Bioavailability of Heavy Metals in Soil: Impact on Microbial Biodegradation of Organic Compounds and Possible Improvement Strategies

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Balakrishna Pillay

2013-05-01

Full Text Available Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation, treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals.

Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine.

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Hernández, A J; Pastor, J

2008-04-01

Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant biodiversity of these grasslands and the bioavailability of heavy metals in the topsoil layer of this abandoned mine. We conducted soil chemical analyses and performed a greenhouse evaluation of the effects of different soil heavy metal concentrations on biodiversity. The greenhouse bioassays were run for 6 months using soil samples obtained from the mine polluted with heavy metals (Cu, Zn, Pb and Cd) and from a control pasture. Soil heavy metal and Na concentrations, along with the pH, had intense negative effects on plant biodiversity, as determined through changes in the Shannon index and species richness. Numbers of grasses, legumes, and composites were reduced, whilst other species (including ruderals) were affected to a lesser extent. Zinc had the greatest effect on biodiversity, followed by Cd and Cu. When we compared the sensitivity of the biodiversity indicators to the different metal content variables, pseudototal metal concentrations determined by X-ray fluorescence (XRF) were the most sensitive, followed by available and soluble metal contents. Worse correlations between biodiversity variables and metal variables were shown by pseudototal contents obtained by plasma emission spectroscopy (ICP-OES). Our results highlight the importance of using as many different indicators as possible to reliably assess the response shown by plants to heavy metal soil pollution.

Heavy metals and soil microbes

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

2009-01-01

The discovery in the early 1980s that soil microorganisms, and in particular the symbiotic bacteria Rhizobium, were highly sensitive to heavy metals initiated a new line of research. This has given us important insights into a range of topics: ecotoxicology, bioavailability of heavy metals, the role

Efficacy of woody biomass and biochar for alleviating heavy metal bioavailability in serpentine soil.

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Bandara, Tharanga; Herath, Indika; Kumarathilaka, Prasanna; Hseu, Zeng-Yei; Ok, Yong Sik; Vithanage, Meththika

2017-04-01

Crops grown in metal-rich serpentine soils are vulnerable to phytotoxicity. In this study, Gliricidia sepium (Jacq.) biomass and woody biochar were examined as amendments on heavy metal immobilization in a serpentine soil. Woody biochar was produced by slow pyrolysis of Gliricidia sepium (Jacq.) biomass at 300 and 500 °C. A pot experiment was conducted for 6 weeks with tomato (Lycopersicon esculentum L.) at biochar application rates of 0, 22, 55 and 110 t ha -1 . The CaCl 2 and sequential extractions were adopted to assess metal bioavailability and fractionation. Six weeks after germination, plants cultivated on the control could not survive, while all the plants were grown normally on the soils amended with biochars. The most effective treatment for metal immobilization was BC500-110 as indicated by the immobilization efficiencies for Ni, Mn and Cr that were 68, 92 and 42 %, respectively, compared to the control. Biochar produced at 500 °C and at high application rates immobilized heavy metals significantly. Improvements in plant growth in biochar-amended soil were related to decreasing in metal toxicity as a consequence of metal immobilization through strong sorption due to high surface area and functional groups.

Bioavailability and phytotoxicity of heavy metals in soils affected by nickel-processing industry in northern Fennoscandia

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Koptsik, G.; Koptsik, S.; Aamlid, D.

2007-01-01

Long-term effects of air pollution have caused strong soil contamination and severe damage to trees and ground vegetation in forest ecosystems in Russia and Norway, in areas near the Pechenganikel smelter, one of the largest emitters of sulfur dioxide in Europe. This paper presented the results of a study that analysed the effects of soil pollution, in particular of nickel and copper pollutants on forest vegetation in surroundings of the smelter. The paper discussed the objects and methods for the study which involved collection of plant and soil samples from almost 100 monitoring plots. Results were discussed in terms of heavy metals in trees and ground vegetation, heavy metals in soils, and plant-soil relationships. Phytotoxicological risk of excess metal input and remediation approaches were also discussed. It was concluded that all of the plant species that were tested exhibited high concentrations of heavy metals, especially nickel and copper and that changes in composition of plant tissues could be explained by changes in element concentrations in soil organic layers where the low pH kept the metals in a bioavailable form. 28 refs., 1 tab, 6 figs

Temporal trends and bioavailability assessment of heavy metals in the sediments of Deception Bay, Queensland, Australia.

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Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

2014-12-15

Thirteen sites in Deception Bay, Queensland, Australia were sampled three times over a period of 7 months and assessed for contamination by a range of heavy metals, primarily As, Cd, Cr, Cu, Pb and Hg. Fraction analysis, enrichment factors and Principal Components Analysis-Absolute Principal Component Scores (PCA-APCS) analysis were conducted in order to identify the potential bioavailability of these elements of concern and their sources. Hg and Te were identified as the elements of highest enrichment in Deception Bay while marine sediments, shipping and antifouling agents were identified as the sources of the Weak Acid Extractable Metals (WE-M), with antifouling agents showing long residence time for mercury contamination. This has significant implications for the future of monitoring and regulation of heavy metal contamination within Deception Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of microscale ZVI/magnetite on methane production and bioavailability of heavy metals during anaerobic digestion of diluted pig manure.

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Liang, Yue-Gan; Li, Xiu-Juan; Zhang, Jin; Zhang, Li-Gan; Cheng, Beijiu

2017-05-01

Low methane production and high levels of heavy metal in pig slurries limit the feasibility of anaerobic digestion of pig manure. In this study, changes in the methane production and bioavailability of heavy metals in the anaerobic digestion of diluted pig manure were evaluated using single and combined action of microscale zero-valence iron (ZVI) and magnetite. After 30 days of anaerobic digestion, the methane yield ranged from 246.9 to 334.5 mL/g VS added, which increased by 20-26% in the group added with microscale ZVI and/or magnetite relative to that in the control group. Results of the first-order kinetic model revealed that addition of microscale ZVI and/or magnetite increased the biogas production potential, rather than the biogas production rate constant. These treatments also changed the distribution of chemical fractions for heavy metal. The addition of ZVI decreased the bioavailability of Cu and Zn in the solid digested residues. Moreover, a better performance was observed in the combined action of microscale ZVI and magnetite, and the ZVI anaerobic corrosion end-product, magnetite, might help enhance methane production through direct interspecies electron transfer in ZVI-anaerobic digestion process.

Labile rhizosphere soil solution fraction for prediction of bioavailability of heavy metals and rare earth elements to plants.

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Shan, Xiao-Quan; Wang, Zhongwen; Wang, Weisheng; Zhang, Shuzhen; Wen, Bei

2003-02-01

A labile rhizosphere soil solution fraction has been recommended to predict the bioavailability of heavy metals and rare earth elements to plants. This method used moist rhizosphere soil in combination with a mixture of 0.01 mol L(-1) of low-molecular-weight organic acids (LMWOAs) as extractant. The extracted soil solutions were fractionated into two colloidal fractions of soil solution fraction, F(lrss). For the soil solutions extracted with a mixture of LMWOAs the concentrations of heavy metals and rare earth elements in F(2) and F(3) were quite similar. However, the mean concentrations of Cr, Ni, Zn, Cu, Pb, Cd, La, Ce, Pr, and Nd in F(lrss) accounted for 79.9%, 91.3%, 90.8%, 60.1%, 77.5%, 75.3%, 81.2%, 77.2%, 80.3%, and 79.5%, respectively, of their concentrations in F(2). In contrast, there were no differences in the extractable metal concentrations between the three fractions while the first step of the method recommended by the European Community of Reference (BCR), where 0.1 mol L(-1) acetic acid was used as an extractant. The single correlation analysis was made between metal concentrations in the different fractions of soil solutions and their concentrations in wheat. If the first step of BCR method was used there was no good correlation between heavy metals in soil pools and that in wheat shoots and roots. When LMWAOs were used a good correlation was obtained between the concentrations of heavy metals in soil pools and that in wheat roots, which followed a general order of r(1 kD, LMWOAs) >r(0.2 microm, LMWOAs) approximately r(0.45 microm, LMWOAs). In the case of rare earth elements the good correlation was obtained for both the wheat roots and shoots. Generally, the correlation coefficients obtained by LMWAOs were better than that obtained by the first step of BCR method. Therefore, LMWAOs and F(lrss) were strongly recommended to predict the bioavailability of metals in soil pools to plants.

The role of tailored biochar in increasing plant growth, and reducing bioavailability, phytotoxicity, and uptake of heavy metals in contaminated soil.

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Mohamed, Badr A; Ellis, Naoko; Kim, Chang Soo; Bi, Xiaotao

2017-11-01

Microwave-assisted catalytic pyrolysis was investigated using K 3 PO 4 and clinoptilolite to enhance biochar sorption affinity for heavy metals. The performance of resulting biochar samples was characterized through their effects on plant growth, bioavailability, phytotoxicity, and uptake of heavy metals in a sandy soil contaminated with Pb, Ni, and Co. The produced biochars have high cation-exchange capacity (CEC) and surface area, and rich in plant nutrients, which not only reduced heavy metals (Pb, Ni, and Co), bioavailability and phytotoxicity, but also increased plant growth rate by up to 145%. The effectiveness of biochar in terms of reduced phytotoxicity and plant uptake of heavy metals was further improved by mixing K 3 PO 4 and clinoptilolite with biomass through microwave pyrolysis. This may be due to the predominance of different mechanisms as 10KP/10Clino biochar has the highest micropore surface area (405 m 2 /g), high concentrations of K (206 g/kg), Ca (26.5 g/kg), Mg (6.2 g/kg) and Fe (11.9 g/kg) for ion-exchange and high phosphorus content (79.8 g/kg) for forming insoluble compounds with heavy metals. The largest wheat shoot length (143 mm) and lowest extracted amounts of Pb (107 mg/kg), Ni (2.4 mg/kg) and Co (63.9 mg/kg) were also obtained by using 10KP/10Clino biochar at 2 wt% load; while the smallest shoot length (68 mm) and highest extracted amounts of heavy metals (Pb 408 mg/kg, Ni 15 mg/kg and Co 148 mg/kg) for the samples treated with biochars were observed for soils mixed with 1 wt% 10Clino biochar. Strong negative correlations were also observed between biochar micropore surface area, CEC and the extracted amounts of heavy metals. Microwave-assisted catalytic pyrolysis of biomass has a great potential for producing biochar with high sorption affinity for heavy metals and rich nutrient contents using properly selected catalysts/additives that can increase microwave heating rate and improve biochar and bio-oil properties

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

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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.

The effect of earthworms on the fractionation and bioavailability of heavy metals before and after soil remediation

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Udovic, Metka; Lestan, Domen

2007-01-01

The effect of two earthworm species, Lumbricus rubellus and Eisenia fetida, on the fractionation/bioavailability of Pb and Zn before and after soil leaching with EDTA was studied. Four leaching steps with total 12.5 mmol kg -1 EDTA removed 39.8% and 6.1% of Pb and Zn, respectively. EDTA removed Pb from all soil fractions fairly uniformly (assessed using sequential extractions). Zn was mostly present in the chemically inert residual soil fraction, which explains its poor removal. Analysis of earthworm casts and the remainder of the soil indicated that L. rubellus and E. fetida actively regulated soil pH, but did not significantly change Pb and Zn fractionation in non-remediated and remediated soil. However, the bioavailability of Pb (assessed using Ruby's physiologically based extraction test) in E. fetida casts was significantly higher than in the bulk of the soil. In remediated soil the Pb bioavailability in the simulated stomach phase increased by 5.1 times. - Earthworm activity increases heavy metal bioavailability in soil before and after remediation

The effect of earthworms on the fractionation and bioavailability of heavy metals before and after soil remediation

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Udovic, Metka [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Lestan, Domen [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia)]. E-mail: domen.lestan@bf.uni-lj.si

2007-07-15

The effect of two earthworm species, Lumbricus rubellus and Eisenia fetida, on the fractionation/bioavailability of Pb and Zn before and after soil leaching with EDTA was studied. Four leaching steps with total 12.5 mmol kg{sup -1} EDTA removed 39.8% and 6.1% of Pb and Zn, respectively. EDTA removed Pb from all soil fractions fairly uniformly (assessed using sequential extractions). Zn was mostly present in the chemically inert residual soil fraction, which explains its poor removal. Analysis of earthworm casts and the remainder of the soil indicated that L. rubellus and E. fetida actively regulated soil pH, but did not significantly change Pb and Zn fractionation in non-remediated and remediated soil. However, the bioavailability of Pb (assessed using Ruby's physiologically based extraction test) in E. fetida casts was significantly higher than in the bulk of the soil. In remediated soil the Pb bioavailability in the simulated stomach phase increased by 5.1 times. - Earthworm activity increases heavy metal bioavailability in soil before and after remediation.

Modelling chelate-Induced phytoextraction: functional models predicting bioavailability of metals in soil, metal uptake and shoot biomass

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Pasqualina Sacco

2006-06-01

Full Text Available Chelate-induced phytoextraction of heavy metals from contaminated soils requires special care to determine, a priori, the best method of chelate application, in terms of both dose and timing. In fact, the chelate dose must assure the bioavailability of the metal to the plant without increasing leaching risk and giving toxic effects. Three mathematical models are here proposed for usefully interpreting the processes taking place: a increased soil bioavailability of metals by chelants; b metal uptake by plants; c variation in plant biomass. The models are implemented and validated using data from pot and lysimeter trials. Both the chelate dose and the time elapsed since its application affected metal bioavailability and plant response. Contrariwise, the distribution strategy (single vs. split application seems to produce significant differences both in plant growth and metal uptake, but not in soil metal bioavailability. The proposed models may help to understand and predict the chelate dose – effect relationship with less experimental work.

Modelling chelate-Induced phytoextraction: functional models predicting bioavailability of metals in soil, metal uptake and shoot biomass

Directory of Open Access Journals (Sweden)

Pasqualina Sacco

Full Text Available Chelate-induced phytoextraction of heavy metals from contaminated soils requires special care to determine, a priori, the best method of chelate application, in terms of both dose and timing. In fact, the chelate dose must assure the bioavailability of the metal to the plant without increasing leaching risk and giving toxic effects. Three mathematical models are here proposed for usefully interpreting the processes taking place: a increased soil bioavailability of metals by chelants; b metal uptake by plants; c variation in plant biomass. The models are implemented and validated using data from pot and lysimeter trials. Both the chelate dose and the time elapsed since its application affected metal bioavailability and plant response. Contrariwise, the distribution strategy (single vs. split application seems to produce significant differences both in plant growth and metal uptake, but not in soil metal bioavailability. The proposed models may help to understand and predict the chelate dose – effect relationship with less experimental work.

Performance of Raphidocelis subcapitata exposed to heavy metal mixtures.

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Expósito, Nora; Kumar, Vikas; Sierra, Jordi; Schuhmacher, Marta; Giménez Papiol, Gemma

2017-12-01

Microalgae growth inhibition assays are candidates for referent ecotoxicological assays, and are a fundamental part in the strategy to reduce the use of fish and other animal models in aquatic toxicology. In the present work, the performance of Raphidocelis subcapitata exposed to heavy metals following standardized growth inhibition assays has been assessed in three different scenarios: 1) dilutions of single heavy metals, 2) artificial mixture of heavy metals at similar levels than those found in natural rivers and, 3) natural samples containing known mixtures of contaminants (heavy metals). Chemical speciation of heavy metals has been estimated with Eh-pH diagram and Visual MINTEQ software; heavy metal and free heavy metal ion concentrations were used as input data, together with microalgae growth inhibition, for Dr. Fit software. The final goal was to assess the suitability of the ecotoxicological test based on the growth inhibition of microalgae cultures, and the mathematic models based on these results, for regulatory and decision-making purposes. The toxicity of a given heavy metal is not only determined by its chemical speciation; other chemical and biological interaction play an important role in the final toxicity. Raphidocelis subcapitata 48h-h-EC50 for tested heavy metals (especially Cu and Zn) were in agreement with previous studies, when ion metal bioavailability was assumed to be 100%. Nevertheless, the calculated growth inhibition was not in agreement with the obtained inhibition when exposed to the artificial mixture of heavy metals or the natural sample. Interactions between heavy metal ions and the compounds of the culture media and/or the natural sample determine heavy metal bioavailability, and eventually their toxicity. More research is needed for facing the challenge posed by pollutant mixtures as they are present in natural environments, and make microalgae-based assays suitable for pollution management and regulatory purposes. Copyright �

Speciation of heavy metals in different grain sizes of Jiaozhou Bay sediments: Bioavailability, ecological risk assessment and source analysis on a centennial timescale.

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Kang, Xuming; Song, Jinming; Yuan, Huamao; Duan, Liqin; Li, Xuegang; Li, Ning; Liang, Xianmeng; Qu, Baoxiao

2017-09-01

Heavy metal contamination is an essential indicator of environmental health. In this work, one sediment core was used for the analysis of the speciation of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in Jiaozhou Bay sediments with different grain sizes. The bioavailability, sources and ecological risk of heavy metals were also assessed on a centennial timescale. Heavy metals were enriched in grain sizes of Pb > Cd > Zn > Cu >Ni > Cr > As. Enrichment factors (EF) indicated that heavy metals in Jiaozhou Bay presented from no enrichment to minor enrichment. The potential ecological risk index (RI) indicated that Jiaozhou Bay had been suffering from a low ecological risk and presented an increasing trend since 1940s owing to the increase of anthropogenic activities. The source analysis indicated that natural sources were primary sources of heavy metals in Jiaozhou Bay and anthropogenic sources of heavy metals presented an increasing trend since 1940s. The principal component analysis (PCA) indicated that Cr, Mn, Ni, Cu and Pb were primarily derived from natural sources and that Zn and Cd were influenced by shipbuilding industry. Mn, Cu, Zn and Pb may originate from both natural and anthropogenic sources. As may be influenced by agricultural activities. Moreover, heavy metals in sediments of Jiaozhou Bay were clearly influenced by atmospheric deposition and river input. Copyright © 2017. Published by Elsevier Inc.

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

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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.

Biosolids and heavy metals in soils

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Silveira Maria Lucia Azevedo

2003-01-01

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

Bioavailability of Cadmium and Zin to Two Earthworm Species in High-metal Soils

OpenAIRE

Liu, Ying

2012-01-01

It was generally recognized that the bioavailability, other than total content of heavy metals in soil, is crucial to predict metals' toxic effect on environment. Stable Isotope Dilution technique (SID) equipped with inductively coupled plasma-mass spectrometry (ICP-MS) is a good way for measuring the potential bioavailable portion of metals in soils. In Chapter 2, we build method to accurately determined Cd (111Cd/114Cd) and the ratio of Zn (66Zn/68Zn) in soil suspension and then applied thi...

Construction of a self- luminescent cyanobacterial bioreporter that detects a broad range of bioavailable heavy metals in aquatic environments

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Keila eMartin-Betancor

2015-03-01

Full Text Available A self-luminescent bioreporter strain of the unicellular cyanobacterium Synechococcus sp. PCC 7942 was constructed by fusing the promoter region of the smt locus (encoding the transcriptional repressor SmtB and the metallothionein SmtA to luxCDABE from Photorhabdus luminescens; the sensor smtB gene controlling the expression of smtA was cloned in the same vector. The bioreporter performance was tested with a range of heavy metals and was shown to respond linearly to divalent Zn, Cd, Cu, Co, Hg and monovalent Ag. Chemical modelling was used to link bioreporter response with metal speciation and bioavailability. Limits of Detection (LODs, Maximum Permissive Concentrations (MPCs and dynamic ranges for each metal were calculated in terms of free ion concentrations. The ranges of detection varied from 11 to 72 pM for Hg2+ (the ion to which the bioreporter was most sensitive to 1.54-5.35 µM for Cd2+ with an order of decreasing sensitivity as follows: Hg2+ >> Cu2+ >> Ag+ > Co2+ ≥ Zn2+ > Cd2+. However, the maximum induction factor reached 75-fold in the case of Zn2+ and 56-fold in the case of Cd2+, implying that Zn2+ is the preferred metal in vivo for the SmtB sensor, followed by Cd2+, Ag+ and Cu2+ (around 45-50-fold induction, Hg2+ (30-fold and finally Co2+ (20-fold. The bioreporter performance was tested in real environmental samples with different water matrix complexity artificially contaminated with increasing concentrations of Zn, Cd, Ag and Cu, confirming its validity as a sensor of free heavy metal cations bioavailability in aquatic environments.

Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

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Rosado, Daniel; Usero, José; Morillo, José

2016-06-01

Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox® bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Migration and speciation of heavy metal in salinized mine tailings affected by iron mining.

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Zhang, Xu; Yang, Huanhuan; Cui, Zhaojie

2017-10-01

The negative effects of heavy metals have aroused much attention due to their high toxicity to human beings. Migration and transformation trend of heavy metals have a close relationship with soil safety. Researching on migration and transformation of heavy metals in tailings can provide a reliable basis for pollution management and ecosystem restoration. Heavy metal speciation plays an important role in risk assessment. We chose Anshan tailings for our study, including field investigations and laboratory research. Four typical heavy metal elements of mine tailings {Fe (373.89 g/kg), Mn (2,303.80 mg/kg), Pb (40.99 mg/kg) and Cr (199.92 mg/kg)} were studied via Tessier test in vertical and horizontal direction. The main speciation of heavy metals in Anshan tailings was the residual. However, heavy metals have a strong ability for migration and transformation in vertical and horizontal directions. Its tendency to change from stable to unstable speciation results in increasing bioavailability and potential bioavailability. Fe, Mn, Pb and Cr showed different ability in the migration and transformation process (Mn > Pb > Fe > Cr) depending on the characteristics of heavy metals and physicochemical properties of the environment.

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops.

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Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

2007-01-01

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

Increased Tolerance to Heavy Metals Exhibited by Swarming Bacteria

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Anyan, M.; Shrout, J. D.

2014-12-01

Pseudomonas aeruginosa is a ubiquitous, Gram-negative bacterium that utilizes several different modes of motility to colonize surfaces, including swarming, which is the coordinated movement of cells over surfaces in groups. Swarming facilitates surface colonization and biofilm development for P. aeruginosa, and it is known that swarming behavior is influenced by changes in nutrient composition and surface moisture. To understand the fate and cycling of heavy metals in the environment, it is important to understand the interaction and toxicity of these metals upon bacteria. While previous studies have shown surface-attached bacterial biofilms to be highly resistant to heavy metal toxicity, little is known about the influence of heavy metals upon surface motile bacteria and developing biofilms. Using a combination of laboratory assays we examined differences in bacterial behavior in response to two metals, Cd and Ni. We find that surface swarming bacteria are able to grow on 4x and 2.5x more Cd and Ni, respectively, than planktonic cells (i.e., test tube cultures). P. aeruginosa was able to swarm in the presence ≤0.051mM Ni and ≤0.045mM Cd. To investigate the bioavailability of metals to bacteria growing under our examined conditions, we separated cell and supernatant fractions of P. aeruginosa cultures, and used ICP-MS techniques to measure Cd and Ni sorption. A greater percentage of Cd than Ni was sorbed by both cells and supernatant (which contains rhamnolipid, a surfactant known to sorb some metals and improve swarming). While we show that cell products such as rhamnolipid bind heavy metals (as expected) and should limit metal bioavailability, our results suggest at least one additional mechanism (as yet undetermined) that promotes cell survival during swarming in the presence of these heavy metals.

A critical review of the bioavailability and impacts of heavy metals in municipal solid waste composts compared to sewage sludge.

Science.gov (United States)

Smith, Stephen R

2009-01-01

The content, behaviour and significance of heavy metals in composted waste materials is important from two potentially conflicting aspects of environmental legislation in terms of: (a) defining end-of-waste criteria and increasing recycling of composted residuals on land and (b) protecting soil quality by preventing contamination. This review examines the effects of heavy metals in compost and amended soil as a basis for achieving a practical and sustainable balance between these different policy objectives, with particular emphasis on agricultural application. All types of municipal solid waste (MSW) compost contain more heavy metals than the background concentrations present in soil and will increase their contents in amended soil. Total concentrations of heavy metals in source-segregated and greenwaste compost are typically below UK PAS100 limits and mechanical segregated material can also comply with the metal limits in UK PAS100, although this is likely to be more challenging. Zinc and Pb are numerically the elements present in the largest amounts in MSW-compost. Lead is the most limiting element to use of mechanically-segregated compost in domestic gardens, but concentrations are typically below risk-based thresholds that protect human health. Composted residuals derived from MSW and greenwaste have a high affinity for binding heavy metals. There is general consensus in the scientific literature that aerobic composting processes increase the complexation of heavy metals in organic waste residuals, and that metals are strongly bound to the compost matrix and organic matter, limiting their solubility and potential bioavailability in soil. Lead is the most strongly bound element and Ni the weakest, with Zn, Cu and Cd showing intermediate sorption characteristics. The strong metal sorption properties of compost produced from MSW or sewage sludge have important benefits for the remediation of metal contaminated industrial and urban soils. Compost and sewage sludge

Effects of heavy metals on plants and resistance mechanisms. A state-of-the-art report with special reference to literature published in Chinese journals.

Science.gov (United States)

Cheng, Shuiping

2003-01-01

As one of the consequences of heavy metal pollution in soil, water and air, plants are contaminated by heavy metals in some parts of China. To understand the effects of heavy metals upon plants and the resistance mechanisms, would make it possible to use plants for cleaning and remediating heavy metal-polluted sites. The research results on the effects of heavy metals on plants and resistant mechanisms are compiled from Chinese publications from scientific journals and university journals, mostly published during the last decade. Effects of heavy metals on plants result in growth inhibition, structure damage, a decline of physiological and biochemical activities as well as of the function of plants. The effects and bioavailability of heavy metals depend on many factors, such as environmental conditions, pH, species of element, organic substances of the media and fertilization, plant species. But, there are also studies on plant resistance mechanisms to protect plants against the toxic effects of heavy metals such as combining heavy metals by proteins and expressing of detoxifying enzyme and nucleic acid, these mechanisms are integrated to protect the plants against injury by heavy metals. There are two aspects on the interaction of plants and heavy metals. On one hand, heavy metals show negative effects on plants. On the other hand, plants have their own resistance mechanisms against toxic effects and for detoxifying heavy metal pollution. To study the effects of heavy metals on plants and mechanisms of resistance, one must select crop cultivars and/or plants for removing heavy metals from soil and water. More highly resistant plants can be selected especially for a remediation of the pollution site. The molecular mechanisms of resistance of plants to heavy metals should be studied further to develop the actual resistance of these plants to heavy metals. Understanding the bioavailability of heavy metals is advantageous for plant cultivation and phytoremediation

Supercritical water treatment of heavy metal and arsenic metalloid-bioaccumulating-biomass.

Science.gov (United States)

Li, Jianxin; Chen, Jinbo; Chen, Shan

2018-08-15

Hyperaccumulator biomass, as a promising resource for renewable energy that can be converted into valuable fuel productions with high conversion efficiency, must be considered as hazardous materials and be carefully treated before further reuse due to the high contents of heavy metals. In this study, Pteris vittata L., an As-hyperaccumulator biomass was treated by an effective and environmental friendly method-supercritical water gasification (SCWG) using a bench-scale batch reactor. The contents of heavy metals (Cd, Pb and Zn) and arsenic metalloid in solid, liquid and gaseous products during SCWG process were thoroughly investigated. The speciation fractions including exchangeable, reducible, oxidizable and residual fractions of each heavy metal as the proportion of the total contents in solid residue were presented and the transformations trend of these heavy metals during the SCWG process was especially demonstrated. The significant operating parameters, including reaction temperature (395-445 °C), pressure (21-27 MPa) and residence time (0-40 min) were varied to explore their effects on the contents and forms. Moreover, the environmental risks of heavy metals in solid residues were evaluated based on risk assessment code, taking into consideration the speciation fractions and bioavailability. It was highlighted that although heavy metals particularly Pb and Zn tended to accumulate in solid residues with a maximum increment of about 50% in the total content, they were mostly converted to more stable oxidizable and residual fractions, and thus the ecotoxicity and bioavailability were greatly mitigated with no obvious increase in direct toxicity fractions. Each tested heavy metal presented no or low risk to the environments after SCWG treatments, meaning that the environmental pollution levels were markedly reduced with no or low risk to the environment. This study highlights the remarkable ability of SCWG for the heavy metal stabilization. Copyright �

Influence of glyphosate and its formulation (Roundup[reg]) on the toxicity and bioavailability of metals to Ceriodaphnia dubia

Energy Technology Data Exchange (ETDEWEB)

Tsui, Martin T.K. [Department of Biology, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Wang Wenxiong [Department of Biology, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Chu, L.M. [Department of Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)]. E-mail: leemanchu@cuhk.edu.hk

2005-11-15

This study examined the toxicological interaction between glyphosate (or its formulation, Roundup[reg]) and several heavy metals to a freshwater cladoceran, Ceriodaphnia dubia. We demonstrated that all binary combinations of Roundup[reg] and metals (Cd, Cu, Cr, Ni, Pb, Se and Zn) exhibited 'less than additive' mixture toxicity, with 48-h LC50 toxic unit>1. Addition of glyphosate alone could significantly reduce the acute toxicity of Ag, Cd, Cr, Cu, Ni, Pb and Zn (but not Hg and Se). The ratio between glyphosate and metal ions was important in determining the mitigation of metal toxicity by glyphosate. A bioaccumulation study showed that in the presence of glyphosate the uptake of some metals (e.g. Ag) was halted but that of others (e.g. Hg) was increased significantly. Therefore, our study strongly suggests that glyphosate and its commercial formulations can control the toxicity as well as the bioavailability of heavy metals in aquatic ecosystems where both groups of chemicals can co-occur. - Glyphosate can control the toxicity and bioavailability of many heavy metals in the aquatic environment.

Influence of glyphosate and its formulation (Roundup[reg]) on the toxicity and bioavailability of metals to Ceriodaphnia dubia

International Nuclear Information System (INIS)

Tsui, Martin T.K.; Wang Wenxiong; Chu, L.M.

2005-01-01

This study examined the toxicological interaction between glyphosate (or its formulation, Roundup[reg]) and several heavy metals to a freshwater cladoceran, Ceriodaphnia dubia. We demonstrated that all binary combinations of Roundup[reg] and metals (Cd, Cu, Cr, Ni, Pb, Se and Zn) exhibited 'less than additive' mixture toxicity, with 48-h LC50 toxic unit>1. Addition of glyphosate alone could significantly reduce the acute toxicity of Ag, Cd, Cr, Cu, Ni, Pb and Zn (but not Hg and Se). The ratio between glyphosate and metal ions was important in determining the mitigation of metal toxicity by glyphosate. A bioaccumulation study showed that in the presence of glyphosate the uptake of some metals (e.g. Ag) was halted but that of others (e.g. Hg) was increased significantly. Therefore, our study strongly suggests that glyphosate and its commercial formulations can control the toxicity as well as the bioavailability of heavy metals in aquatic ecosystems where both groups of chemicals can co-occur. - Glyphosate can control the toxicity and bioavailability of many heavy metals in the aquatic environment

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

Effects of soil water content and organic matter addition on the speciation and bioavailability of heavy metals

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Soriano, Maria C., E-mail: maria.HernandezSoriano@ees.kuleuven.be [Department of Soil Science, College of Agriculture and Life Sciences, North Carolina State University, Campus Box 7619, 101 Derieux Street, 2232 Williams Hall, Raleigh, NC 27695 (United States); Jimenez-Lopez, Jose C. [Department of Biological Sciences, College of Science, Purdue University, 201 S. University Street, West Lafayette, IN 47907 (United States)

2012-04-15

The mobility and bioavailability of cadmium, copper, lead and zinc were evaluated in three soils amended with different organic materials for two moisture regimes. Agricultural and reclamation activities impose fresh inputs of organic matter on soil while intensive irrigation and rainstorm increase soil waterlogging incidence. Moreover, scarcity of irrigation water has prompted the use of greywater, which contain variable concentrations of organic compounds such as anionic surfactants. Soils added with hay, maize straw or peat at 1% w/w were irrigated, at field capacity (FC) or saturated (S), with an aqueous solution of the anionic surfactant Aerosol 22 (A22), corresponding to an addition of 200 mg C/kg soil/day. Soil solution was extracted after one month and analysed for total soluble metals, dissolved soil organic matter and UV absorbance at 254 nm. Speciation analyses were performed with WHAM VI for Cd, Cu, Pb, and Zn. For selected scenarios, metal uptake by barley was determined. Metal mobility increased for all treatments and soils (Pb > Cu > Cd {>=} Zn) compared to control assays. The increase was significantly correlated (p < 0.05) with soil organic matter solubilisation for Cd (R = 0.68), Cu (R = 0.73) and Zn (R = 0.86). Otherwise, Pb release was related to aluminium solubilisation (R = 0.75), which suggests that Pb was originally co-precipitated with Al-DOC complexes in the solid phase. The effect of A22 in metal bioavailability, determined as free ion activities (FIA), was mainly controlled by soil moisture regime. For soil 3, metal bioavailability was up to 20 times lower for soil amended with hay, peat or maize compared to soil treated only with A22. When soil was treated with A22 at FC barley yield significantly decreased (p < 0.05) for the increase of Pb (R = 0.71) and Zn (R = 0.79) concentrations in shoot, while for saturated conditions such uptake was up to 3 times lower. Overall, metal bioavailability was controlled by solubilisation of soil

Heavy metals contamination of soil and fodder: a possible risk to livestock

International Nuclear Information System (INIS)

Ahmad, K.; Shaheen, M.; Khan, Z.I.

2013-01-01

Heavy metals are significant ecological pollutant, principally in areas with sky-scraping anthropogenic stress. Their existence in the environment, soil and water, still in traces can cause severe tribulations to all organisms; heavy metal bioaccumulation in the food chain particularly can be extremely hazardous to animal and human health. Heavy metals generally come into the body by breathing and eating, ingestion being the most important route of contact to these elements in animals. The current study was conducted to examine lead (Pb), cadmium (Cd) and chromium (Cr) in the soil and fodders. Representative samples of soil were collected during two different seasons from two different sites, known as feeding sites for ruminants and analysed for heavy metals after wet digestion, using Atomic Absorption Spectrophotometer. The results showed that location and season had a significant effect (P>0.001) on soil and heavy metal concentrations. Soil and forage Pb, Cd, and Cr concentrations were higher in summer than in winter. From the results of the current study, it was determined that all the metals in soil were lower than deadly levels, posing no probable threat to both plant and animal life. There is an incessant need for monitoring the bioavailability of these heavy metals to grazing livestock, principally in summer season when these metals were found in relatively elevated concentrations, so that their possible toxic consequence to the grazing livestock can not be permitted. Agronomic practices, such as, manure and water managements as well as crop alternation system, can affect bioavailability and crop accretion of heavy metals, thus influencing the thresholds for assessing nutritional toxicity of heavy metals in the foodstuff. This study would be important for livestock owners and scientists working in extension services in Pakistan and other countries with same ecological condition. (author)

Effects of soil water content and organic matter addition on the speciation and bioavailability of heavy metals

International Nuclear Information System (INIS)

Hernandez-Soriano, Maria C.; Jimenez-Lopez, Jose C.

2012-01-01

The mobility and bioavailability of cadmium, copper, lead and zinc were evaluated in three soils amended with different organic materials for two moisture regimes. Agricultural and reclamation activities impose fresh inputs of organic matter on soil while intensive irrigation and rainstorm increase soil waterlogging incidence. Moreover, scarcity of irrigation water has prompted the use of greywater, which contain variable concentrations of organic compounds such as anionic surfactants. Soils added with hay, maize straw or peat at 1% w/w were irrigated, at field capacity (FC) or saturated (S), with an aqueous solution of the anionic surfactant Aerosol 22 (A22), corresponding to an addition of 200 mg C/kg soil/day. Soil solution was extracted after one month and analysed for total soluble metals, dissolved soil organic matter and UV absorbance at 254 nm. Speciation analyses were performed with WHAM VI for Cd, Cu, Pb, and Zn. For selected scenarios, metal uptake by barley was determined. Metal mobility increased for all treatments and soils (Pb > Cu > Cd ≥ Zn) compared to control assays. The increase was significantly correlated (p < 0.05) with soil organic matter solubilisation for Cd (R = 0.68), Cu (R = 0.73) and Zn (R = 0.86). Otherwise, Pb release was related to aluminium solubilisation (R = 0.75), which suggests that Pb was originally co-precipitated with Al–DOC complexes in the solid phase. The effect of A22 in metal bioavailability, determined as free ion activities (FIA), was mainly controlled by soil moisture regime. For soil 3, metal bioavailability was up to 20 times lower for soil amended with hay, peat or maize compared to soil treated only with A22. When soil was treated with A22 at FC barley yield significantly decreased (p < 0.05) for the increase of Pb (R = 0.71) and Zn (R = 0.79) concentrations in shoot, while for saturated conditions such uptake was up to 3 times lower. Overall, metal bioavailability was controlled by solubilisation of soil

Changes in heavy metal bioavailability and speciation from a Pb-Zn mining soil amended with biochars from co-pyrolysis of rice straw and swine manure.

Science.gov (United States)

Meng, Jun; Tao, Mengming; Wang, Lili; Liu, Xingmei; Xu, Jianming

2018-08-15

Biochar has been utilized as a good amendment to immobilize heavy metals in contaminated soils. However, the effectiveness of biochar in metal immobilization depends on biochar properties and metal species. In this study, the biochars produced from co-pyrolysis of rice straw with swine manure at 400°C were investigated to evaluate their effects on bioavailability and chemical speciation of four heavy metals (Cd, Cu, Pb and Zn) in a Pb-Zn contaminated soil through incubation experiment. Results showed that co-pyrolysis process significantly change the yield, ash content, pH, and electrical conductivity (EC) of the blended biochars compared with the single straw/manure biochar. The addition of these biochars significantly increased the soil pH, EC, and dissolved organic carbon (DOC) concentrations. The addition of biochars at a rate of 3% significantly reduced the CaCl 2 -extractable metal concentrations in the order of Pb>Cu>Zn>Cd. The exchangeable heavy metals decreased in all the biochar-amended soils whereas the carbonate-bound metal speciation increased. The increase in soil pH and the decrease in the CaCl 2 extractable metals indicated that these amendments can directly transform the highly availability metal speciation to the stable speciation in soils. In conclusion, biochar derived from co-pyrolysis of rice straw with swine manure at a mass ratio of 3:1 could most effectively immobilize the heavy metals in the soil. Copyright © 2018 Elsevier B.V. All rights reserved.

PLANT CONTAMINATION AND PHYTOTOXICITY DUE TO HEAVY METALS FROM SOIL AND WATER

Directory of Open Access Journals (Sweden)

Judith Prieto Mendez

2008-12-01

Full Text Available High levels of heavy metals, such as: lead, nickel, cadmium and manganese, which are present in soil and wastewater used for agricultural irrigation, are due to the fact that these metals can be accumulated into these systems, of main importance for agriculture. Because of its non-biodegradability features, toxicity effects onto several crops and consequences on their bio-availability, this may result hazardous. This literature survey highlights and remarks relative sensitivity of some plants before heavy metals presence and crops trend to accumulate them, emphasizing aspects related to some soil physicochemical characteristics and heavy metals phyto-toxicity.

Bioavailability of Sediment-bound Heavy Metals on the East African ...

African Journals Online (AJOL)

The results revealed that heavy metal levels at some locations were higher than at others. Cd, Mn and Co were more concentrated in labile fractions compared to the other elements. These metals are easily liberated into overlying water, making them available for biological uptake. More than 62% of the total concentrations ...

Review of Phosphate in soils: Interaction with micronutrients, radionuclides, and heavy metals

Science.gov (United States)

Phosphate-phosphorus present in the vadose zone of soil as native, added, or residual fertilizer influences the retention, transport, and bioavailability of heavy metals, metalloids, or metallic radionuclides to aboveground vegetation, soil microorganisms, and fauna that browse that vegetation, or d...

Potential of siderophore-producing bacteria for improving heavy metal phytoextraction.

Science.gov (United States)

Rajkumar, Mani; Ae, Noriharu; Prasad, Majeti Narasimha Vara; Freitas, Helena

2010-03-01

Phytoremediation holds promise for in situ treatment of heavy metal contaminated soils. Recently, the benefits of combining siderophore-producing bacteria (SPB) with plants for metal removal from contaminated soils have been demonstrated. Metal-resistant SPB play an important role in the successful survival and growth of plants in contaminated soils by alleviating the metal toxicity and supplying the plant with nutrients, particularly iron. Furthermore, bacterial siderophores are able to bind metals other than iron and thus enhance their bioavailability in the rhizosphere of plants. Overall, an increase in plant growth and metal uptake will further enhance the effectiveness of phytoremediation processes. Here, we highlight the diversity and ecology of metal resistant SPB and discuss their potential role in phytoremediation of heavy metals.

Heavy metal toxicity and bioavailability of dissolved nutrients to a bacterivorous flagellate are linked to suspended particle physical properties

International Nuclear Information System (INIS)

Boenigk, Jens; Wiedlroither, Anneliese; Pfandl, Karin

2005-01-01

Many dissolved substances attach easily to sediment particles. In the presence of suspended sediments bioavailability of dissolved substances is therefore, usually reduced and clays are even applied to 'wash' natural waters upon pollution. In organisms which feed on food organisms in the size range of these suspended sediment particles, however, bioavailability of such substances may even increase. For microorganisms the interaction with dissolved substances and suspended sediment particles so far has hardly been investigated. We specifically tested: (1) the importance of suspended particles as an uptake route for dissolved substances; and (2) the significance of particle surface properties, i.e. surface load and mineralogy. As a model system we used an axenically cultured strain of a widespread and often abundant flagellate ('Spumella-like' flagellate strain JBM10). We tested the toxicity of cadmium (II) and mercury (II) as well as availability of dissolved organic matter (DOM) in the absence as well as in the presence of different natural clays, i.e. a kaolinite, a montmorillonite, and a mixed clay, and of artificial silicate particles of different surface charge. When applied separately the presence of the heavy metals cadmium and mercury as well as of suspended particles negatively affected the investigated flagellate but nutritive organics supported growth of the investigated flagellate. Toxic stress response comprises behavioral changes including enhanced swimming activity and stress egestion of ingested particles and was generally similar for a variety of different flagellate species. In combination with suspended particles, the respective effect of trace metals and nutritive substances decreased. Regarding the particle quality, cadmium toxicity increased with increasingly negative surface charge, i.e. increasing surface density of silanol groups (Pearson's product moment, P = 0.005). For mercury particle mineralogy still had a significant effect (P < 0

Incorporation of metal bioavailability into regulatory frameworks-metal exposure in water and sediment

Energy Technology Data Exchange (ETDEWEB)

Ahlf, Wolfgang [Inst. of Environmental Tech. and Energy Economics, TUHH, Hamburg (Germany); Drost, Wiebke [Umweltpruefung Chemikalien IV, Umweltbundesamt, Dessau (Germany); Heise, Susanne [Dept. of Life Sciences, HAW, Hamburg (Germany)

2009-10-15

Background, aim, and scope The cause for this position paper is the impression that risk assessors consider primarily the concentration of free metal ions dissolved in solution controlling metal bioavailability in aquatic systems. Aiming at a more realistic risk assessment of metals, bioavailability has to be discussed under the scope of main uptake routes of metals to organisms. Materials and methods On the basis of a review on the literature relating to bioavailability approaches, this work discusses the incorporation of metal bioavailability into the risk assessment of metals in the context of metal exposure. Results The biotic ligand model (BLM) and the concept of sulfide bound metals described by the ratio of simultaneously extracted metals and acid volatile sulfide concept (AVS) have been developed to consider the bioavailability of metals. Both approaches assume that the free ion concentration is the most relevant exposure pathway. However, apart from geochemical conditions, which control free metal concentration, bioavailability is additionally a result of contaminant/particle interaction and of organisms' activity. Asking for the relevant exposure pathways for inorganic metals to organisms, the compartments' water and sediment have been evaluated and also the importance of contaminated food. (orig.)

Risk assessment of heavy metal pollution for detritivores in floodplain soils in the Biesbosch, The Netherlands, taking bioavailability into account

International Nuclear Information System (INIS)

Hobbelen, P.H.F.; Koolhaas, J.E.; Gestel, C.A.M. van

2004-01-01

Floodplains of the European rivers Rhine and Meuse are heavily polluted. We investigated the risk of heavy metal pollution (Cd, Cu, Pb, Zn) for detritivores living in a floodplain area, the Biesbosch, the Netherlands, affected by these rivers. Total soil, pore water and 0.01 M CaCl 2 extractable concentrations and concentrations in plant leaves, earthworms, isopods and millipedes were measured in two sites and compared with literature data to assess possible risks. Based on total metal concentrations in soil, serious effects on detritivores were expected. However, 0.01 M CaCl 2 extractable, pore water and plant leaf concentrations were similar to metal concentrations found in unpolluted areas. Concentrations of Cu and Cd in earthworms and Cu in millipedes were higher in the Biesbosch than in animals from reference areas. All other measured concentrations of heavy metals in earthworms, isopods and millipedes were similar to the ones found in reference areas. Despite high total soil concentrations, effects of Zn, Cu, Pb and Cd pollution on isopods are therefore not expected, while millipedes may only be affected by Cu. Since Cu and Cd levels in earthworms were increased compared to animals in unpolluted soils, this faunal group seems to be most at risk. Given the engineering role of earthworms in ecosystems, effects on the ecological functioning of floodplain soils therefore cannot be excluded. - Low bioavailability reduced the impact on detritivores

Analysis of heavy metals in road-deposited sediments.

Science.gov (United States)

Herngren, Lars; Goonetilleke, Ashantha; Ayoko, Godwin A

2006-07-07

Road-deposited sediments were analysed for heavy metal concentrations at three different landuses (residential, industrial, commercial) in Queensland State, Australia. The sediments were collected using a domestic vacuum cleaner which was proven to be highly efficient in collecting sub-micron particles. Five particle sizes were analysed separately for eight heavy metal elements (Zn, Fe, Pb, Cd, Cu, Cr, Al and Mn). At all sites, the maximum concentration of the heavy metals occurred in the 0.45-75 microm particle size range, which conventional street cleaning services do not remove efficiently. Multicriteria decision making methods (MCDM), PROMETHEE and GAIA, were employed in the data analysis. PROMETHEE, a non-parametric ranking analysis procedure, was used to rank the metal contents of the sediments sampled at each site. The most polluted site and particle size range were the industrial site and the 0.45-75 microm range, respectively. Although the industrial site displayed the highest metal concentrations, the highest heavy metal loading coincided with the highest sediment load, which occurred at the commercial site. GAIA, a special form of principal component analysis, was applied to determine correlations between the heavy metals and particle size ranges and also to assess possible correlation with total organic carbon (TOC). The GAIA-planes revealed that irrespective of the site, most of the heavy metals are adsorbed to sediments below 150 microm. A weak correlation was found between Zn, Mn and TOC at the commercial site. This could lead to higher bioavailability of these metals through complexation reactions with the organic species in the sediments.

Shells of Nerita gastropod bio-monitors of heavy metals pollution around the Indian Ocean

International Nuclear Information System (INIS)

Badran, M.I.

1999-01-01

Minor and heavy metals Mg, Sr, Mn, Fe and Zn were measured in individual shells of four different Nerita species collected from Phuket Island, Thailand. Shell weight and crystallography were also recorded. Heavy metal concentrations were poorly correlated with both shell weight and crystallography. Out of the four species, N. albicilla acquired the highest heavy metal concentrations. Subsequently shells of N. albicilla collected from different sites around the Indian Ocean were compared for their metal concentrations. Shells of industrial sites in Kenya and India had significantly higher heavy metal concentrations than shells from pristine sites in Mauritius and Aldabra. Discussing the factors that may affect the shell metal concentration, the variations encountered herein are best attributed to the ambient bio-available metal concentration. (author)

The study of heavy metals leaching from waste foundry sands using a one-step extraction

Science.gov (United States)

Bożym, Marta

2017-10-01

There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.). Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni) from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

Phytotoxicity attenuation in Vigna radiata under heavy metal stress at the presence of biochar and N fixing bacteria.

Science.gov (United States)

Seneviratne, Mihiri; Weerasundara, Lakshika; Ok, Yong Sik; Rinklebe, Jörg; Vithanage, Meththika

2017-01-15

This study assesses the effect of N-fixing bacteria and biochar synergism on plant growth and development of Vigna mungo under heavy metal stress (HM). Heavy metal stress is a worldwide problem, which causes critical effects on plant life due to oxidative stress. Application of biochar is a recent biological remediation technique, which often leads to an immobilization of heavy metals in soil. . Synergism of bacteria and biochar is a novel aspect to enhance plant growth under heavy metal stress. Woody biochar a byproduct of a dendro power industry was added as 1, 2.5 and 5% amounts combination with Bradyrhizobium japonicum, where mung seedlings were planted in serpentine soil rich in Ni, Mn, Cr and Co. Pot experiments were conducted for 12 weeks. The plant height, heavy metal uptake by plants, soil bioavailable heavy metal contents, soil N and P and microbial biomass carbon (MBC) were measured. The plant growth was enhanced with biochar amendment but a retardation was observed with high biochar application (5%). The soil N and P increased with the increase of biochar addition percentage while soil MBC showed reductions at 5% biochar amendment. Both soil bioavailable fractions of HM and up take of HMs by plants were gradually reduced with increase in biochar content. Based on the results, 2.5% biochar synergism with bacteria was the best for plant growth and soil nutrition status. Despite the synergism, available N was negatively correlated with the decrease of bioavailable metal percentage in soil whereas it was conversely for P. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of heavy metals bioavailability in dumpsites of Zaria ...

African Journals Online (AJOL)

SERVER

2008-01-18

Jan 18, 2008 ... Cd, Cu, Mn, Pb and Zn in refuse waste soils of some dumpsites in Zaria metropolis. The heavy metals .... soil solution ratio) in acid digestion Teflon cup. It was dry ashed ..... of Cu, Pb, Cd and Zn in soils from or near Donana National Park. J. Environ. ... Administrative Divisions of the World. http://www.world-.

Study on Characteristics of Soil Elements Bio-availability and Their Interrelationship in Black Soil Area of Jilin Province

Science.gov (United States)

Wang, D. Y.

2015-12-01

Abstract: Based on systematic field investigation and surface soil(0-20cm) sampling in the middle part of Jilin province where the soil type mainly consists of black soil and chernozem, soil total content and bio-available content of Fe, Fe, Ca, Mg, K, P, Cu, Zn, Ni, Cr, B, Cd, As were tested. This paper summarizes the geochemical characteristics of the soil elements and takes the ratio of bio-available content to total content as the bio-availability characteristic of each element in soil and studies the interrelationship between their geochemical characteristics of bio-availability by PCA and correlation analysis. Cd、Cr、Ni、Zn、P、Ca are selected out by PCA due to the similar impact under 4 principal components. And their correlation analysis results indicate: the correlation coefficients between heavy metal elements(Cr, Cd, Zn, Ni) bio-availability are significant positive, i.e., the same spatial variation trends are found between them in study area; the same relationships are also found between the bioavailability of P and 4 heavy metal elements (Cr, Cd, Zn, Ni), the promotion of the bioavailability of heavy metal elements goes with P; However, the correlation coefficients between heavy metal(Cr, Cd, Zn, Ni) bio-availability and Ca are mostly significant negative and the adverse spatial variation trends are found between them. The promotion of the bioavailability of heavy metal elements goes against Ca. Key words: soil geochemistry; soil heavy metals; elements interaction; bio-availability

[Heavy metals: soil characteristics and methods of evaluating parameters for defining "contaminated soils"].

Science.gov (United States)

Gagliano-Candela, R; Cammarota, R

2000-01-01

The excessive content of toxic elements in the human environment is associated with the etiology of a number of diseases. Soils' pollutants decontamination regards the main industrialised countries. Heavy metals represent the main problem for soil pollution characterisation. The first approach for pollution evaluation is the determination of total metal concentration; the evaluation of their bioavailability is required for a correct knowledge of the environmental risk. In the present work is shown the procedure to evaluate the sites, which require decontamination and which need the following data: knowledge of the threshold for each metal in the soil and its range, chemical analysis of the components, determination of bioavailability and soil destination. The bioavailability is easily calculated by the procedure of aimed extractions.

Temporal variations and spatial distributions of heavy metals in a wastewater-irrigated soil-eggplant system and associated influencing factors.

Science.gov (United States)

Ai, Shiwei; Liu, Bailin; Yang, Ying; Ding, Jian; Yang, Wenzhi; Bai, Xiaojuan; Naeem, Sajid; Zhang, Yingmei

2018-05-30

Heavy metal pollution in farmlands is highly concerned as crops' easy-uptake of heavy metal can ultimately affect consumers. In order to offer suggestions on cultivating safe quality vegetable, specifically eggplant which is widely consumed for its nutritional value and antioxidant activity, a field study was undertaken to investigate the temporal variations and spatial distributions of heavy metals in a wastewater-irrigated soil-eggplant system. In the present study, eggplants were planted in the farmlands of Weichuan village (WC) (relatively unpolluted field), Liangzhuang village (LZ) (moderately polluted field) and Minqin village (MQ) (seriously polluted field) to elucidate their temporal uptake processes of heavy metals described by the sigmoid model. Eggplant tissues from severely polluted farmlands were found with higher heavy metal concentrations and lower yields compared with other two groups. What is more, 25 farmlands along the Dongdagou stream (heavy metals polluted stream) were chosen to analyze the spatial distribution of heavy metals in soils and eggplants. Heavy metal concentrations in eggplants decreased with the decline of heavy metal concentrations in soil from upstream (pollution source) to downstream. Moreover, several methods were employed to assess bioavailability of heavy metals in soils. All the bioavailable heavy metals were found in linear positive correlations with heavy metal concentrations. Meanwhile, linear correlations were found between heavy metals in soils and eggplants. At last, redundancy analysis was used to investigate the effects of soil properties (pH, organic matter and texture of soils) and heavy metals on eggplants' uptake. The results indicated that soil heavy metals had a dominant impact on their accumulations in eggplant fruit, with a variance contribution of 78.0%, while soil properties had a regulatory effect, with a variance contribution of 5.2%. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of pH and concentration on heavy metal speciation and mobility, and its relation to heavy metal hyperaccumulation and distribution in selected native Australian flora

International Nuclear Information System (INIS)

Menon, D.D.; McPhail, D.C.; Hallam, N.

2000-01-01

Full text: The purpose of this research is to establish a clearer understanding of the relations that exist between heavy metal activity, speciation, bioavailability and their uptake and spatial distribution into plants. A combination of experimental modeling and pot trials using toxic heavy metals (cadmium, lead, mercury, copper, chromium and zinc) will be carried out. In the experiments, selected native Australian flora (Eucalyptus, Acacia, Atriplex) adapted to adverse environmental conditions will be used. Varying external factors such as pH, and metal concentration altered the composition of heavy metal speciation in the soil solution. Mathematical and geochemical (PHREEQC) models were used to vary these factors and emulate the conditions under which experimentation will be taking place. These variations help determine the possible heavy metal speciation that would occur in both soil and hydroponic based experiments under given conditions. The rhizosphere, soil solution and the plant material will be analysed by Inductively Coupled Plasma Mass Spectroscopy (ICPMS). Proton Ion X-ray Emission (PIXE) and Secondary Ion Mass spectrometry will help ascertain the distribution, concentration of heavy metal taken up into plant tissues. Information derived from these data will be used to determine and understand how varying such environmental conditions and hence heavy metal speciation affect their bioavailability in the medium, and how their acceptance, accumulation and storage within the selected flora. Preliminary experimentation showed that, for lead and cadmium, the variation in soil solution pH affected the quantity of heavy metal accumulated into selected native Australian flora. ICP-MS analysis of plants subjected to a known soil solution spiked with 200 μmol of lead and cadmium showed that the quantities of lead and cadmium accumulated into plant sections (roots, stems and leaves) varied in the selected woody species. A. heteroclita, A. saligna, and A

Heavy metal speciation in solid-phase materials from a bacterial sulfate reducing bioreactor using sequential extraction procedure combined with acid volatile sulfide analysis.

Science.gov (United States)

Jong, Tony; Parry, David L

2004-04-01

Heavy metal mobility, bioavailability and toxicity depends largely on the chemical form of metals and ultimately determines potential for environmental pollution. For this reason, determining the chemical form of heavy metals and metalloids, immobilized in sludges by biological mediated sulfate reduction, is important to evaluate their mobility and bioavailability. A modified Tessier sequential extraction procedure (SEP), complemented with acid volatile sulfide (AVS) and simultaneous extracted metals (SEM) measurements, were applied to determine the partitioning of five heavy metals (defined as Fe, Ni, Zn and Cu, and the metalloid As) in anoxic solid-phase material (ASM) from an anaerobic, sulfate reducing bioreactor into six operationally defined fractions. These fractions were water soluble, exchangeable, bound to carbonates (acid soluble), bound to Fe-Mn oxides (reducible), bound to organic matter and sulfides (oxidizable) and residual. It was found that the distribution of Fe, Ni, Zn, Cu and As in ASM was strongly influenced by its association with the above solid fractions. The fraction corresponding to organic matter and sulfides appeared to be the most important scavenging phases of As, Fe, Ni, Zn and Cu in ASM (59.8-86.7%). This result was supported by AVS and SEM (Sigma Zn, Ni and Cu) measurements, which indicated that the heavy metals existed overwhelmingly as sulfides in the organic matter and sulfide fraction. A substantial amount of Fe and Ni at 16.4 and 20.1%, respectively, were also present in the carbonate fraction, while an appreciable portion of As (18.3%) and Zn (19.4%) was bound to Fe-Mn oxides. A significant amount of heavy metals was also associated with the residual fraction, ranging from 2.1% for Zn to 18.8% for As. Based on the average total extractable heavy metal (TEHM) values, the concentration of heavy metals in the ASM was in the order of Cu > Ni > Zn > Fe > As. If the mobility and bioavailability of heavy metals are assumed to be

The study of heavy metals leaching from waste foundry sands using a one-step extraction

Directory of Open Access Journals (Sweden)

Bożym Marta

2017-01-01

Full Text Available There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.. Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

Heavy metal sequestration by humic substances during phyto-treatment of sewage sludges

International Nuclear Information System (INIS)

Peruzzi, E.; Doni, S.; Macci, C.; Ceccanti, B.; Masciandaro, G.

2009-01-01

The presence of heavy metals in sludges stabilized in a reed bed system, may affect their use for agricultural purposes; however, the environmental impact of sludges depends on the availability and phyto toxicity of their heavy metal. The aim of this paper was to determine the effectiveness of a reed bed (Phragmites Australia) sludge treatment system in two urban wastewater treatment plants in Italy after two-year period of operation: by estimating the process of sludge stabilization, following conventional and non conventional parameters related with the evolution of organic matter quality Water soluble Carbon, Dehydrogenase activity, Fulvic Acids, Humic Acids, Pyrolytic indices or organic matter Mineralization and Humification); by following the heavy metal speciation bioavailability in sludges. (Author)

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.

Bioavailability of heavy metals in water and sediments from a typical Mediterranean Bay (Málaga Bay, Region of Andalucía, Southern Spain).

Science.gov (United States)

Alonso Castillo, M L; Sánchez Trujillo, I; Vereda Alonso, E; García de Torres, A; Cano Pavón, J M

2013-11-15

Concentrations of heavy metals were measured in sediment and water from Málaga Bay (South Spain). In the later twentieth century, cities such as Málaga, have suffered the impact of mass summer tourism. The ancient industrial activities, and the actual urbanization and coastal development, recreation and tourism, wastewaters treatment facilities, have been sources of marine pollution. In sediments, Ni was the most disturbing metal because Ni concentrations exceeded the effects range low (ERL), concentration at which toxicity could start to be observed in 85% of the samples analyzed. The metal bioavailability decreased in the order: Cd>Ni>Pb>Cu>Cr. In the sea water samples, Cd and Pb were the most disturbing metals because they exceeded the continuous criteria concentration (CCC) of US EPA in a 22.5% and 10.0% of the samples, respectively. Statistical analyses (ANOVA, PCA, CA) were performed. Copyright © 2013 Elsevier Ltd. All rights reserved.

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 ...

Assessment of the distribution, bioavailability and ecological risks of heavy metals in the lake water and surface sediments of the Caohai plateau wetland, China

Science.gov (United States)

Hu, Jing; Zhou, Shaoqi; Wu, Pan; Qu, Kunjie

2017-01-01

In this study, selected heavy metals (Hg, As, Cd, Pb, Cr, Cu and Zn) in the lake water and sediments from the Caohai wetland, which is a valuable state reserve for migrant birds in China, were investigated to assess the spatial distribution, sources, bioavailability and ecological risks. The results suggested that most of the higher concentrations were found in the eastern region of the lakeshore. The concentration factor (CF) revealed that Hg, Cd and Zn were present from moderate risk levels to considerable risk levels in this study; thus, based on the high pollution load index (PLI) values, the Caohai wetland can be considered polluted. According to the associated effects-range classification, Cd may present substantial environmental hazards. An investigation of the chemical speciation suggested that Cd and Zn were unstable across most of the sites, which implied a higher risk of quick desorption and release. Principal component analysis (PCA) indicated that the heavy metal contamination originated from both natural and anthropogenic sources. PMID:29253896

Assessment of the distribution, bioavailability and ecological risks of heavy metals in the lake water and surface sediments of the Caohai plateau wetland, China.

Directory of Open Access Journals (Sweden)

Jing Hu

Full Text Available In this study, selected heavy metals (Hg, As, Cd, Pb, Cr, Cu and Zn in the lake water and sediments from the Caohai wetland, which is a valuable state reserve for migrant birds in China, were investigated to assess the spatial distribution, sources, bioavailability and ecological risks. The results suggested that most of the higher concentrations were found in the eastern region of the lakeshore. The concentration factor (CF revealed that Hg, Cd and Zn were present from moderate risk levels to considerable risk levels in this study; thus, based on the high pollution load index (PLI values, the Caohai wetland can be considered polluted. According to the associated effects-range classification, Cd may present substantial environmental hazards. An investigation of the chemical speciation suggested that Cd and Zn were unstable across most of the sites, which implied a higher risk of quick desorption and release. Principal component analysis (PCA indicated that the heavy metal contamination originated from both natural and anthropogenic sources.

Comparative study on the hepatoprotection to heavy metals of Zingiber officinale.

Science.gov (United States)

Nwokocha, Chukwuemeka R; Owu, Daniel U; Nwokocha, Magdalene I; Ufearo, Chibueze S; Iwuala, Moses O E

2012-10-01

Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. MATERIALS #ENTITYSTARTX00026; Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (PZingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver.

Bioremediation mechanisms of combined pollution of PAHs and heavy metals by bacteria and fungi: A mini review.

Science.gov (United States)

Liu, Shao-Heng; Zeng, Guang-Ming; Niu, Qiu-Ya; Liu, Yang; Zhou, Lu; Jiang, Lu-Hua; Tan, Xiao-Fei; Xu, Piao; Zhang, Chen; Cheng, Min

2017-01-01

In recent years, knowledge in regard to bioremediation of combined pollution of polycyclic aromatic hydrocarbons (PAHs) and heavy metals by bacteria and fungi has been widely developed. This paper reviews the species of bacteria and fungi which can tackle with various types of PAHs and heavy metals entering into environment simultaneously or successively. Microbial activity, pollutants bioavailability and environmental factors (e.g. pH, temperature, low molecular weight organic acids and humic acids) can all affect the bioremediation of PAHs and heavy metals. Moreover, this paper summarizes the remediation mechanisms of PAHs and heavy metals by microbes via elucidating the interaction mechanisms of heavy metals with heavy metals, PAHs/PAHs metabolites with PAHs and PAHs with heavy metals. Based on the above reviews, this paper also discusses the potential research needs for this field. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan.

Science.gov (United States)

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH)(2) in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb>Cd>Cr, but the order was changed to Pb>Cr>Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan

International Nuclear Information System (INIS)

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH) 2 in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb > Cd > Cr, but the order was changed to Pb > Cr > Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only

Transformation of heavy metals in lignite during supercritical water gasification

International Nuclear Information System (INIS)

Chen, Guifang; Yang, Xinfei; Chen, Shouyan; Dong, Yong; Cui, Lin; Zhang, Yong; Wang, Peng; Zhao, Xiqiang; Ma, Chunyuan

2017-01-01

Highlights: • The transformations of heavy metals during lignite SCWG were investigated. • The risks of heavy metals in lignite and residues after SCWG were evaluated. • The effects of experimental conditions on corrosion during SCWG were studied. - Abstract: Transformation characteristics of heavy metals during lignite supercritical water gasification (SCWG) were studied. A sequential extraction procedure (modified Tessier method) was used to selectively extract different fractions of Pb, Cd, Cr, Mn, Cu, Ni, and Zn. Heavy metals transformed into more stable fractions after SCWG. For Pb, Cd, Mn, Cu, and Zn, SCWG reduced the bioavailability and the risks posed by heavy metals in lignite. Under the experimental conditions, the conversion rates for Pb and Cd were 16.0%–25.2% and 16.3%–23.4%, respectively, whereas those for Mn, Cu, and Zn were much lower. Solid products enriched with Pb, Cd, Mn, Cu, and Zn were obtained after SCWG; the contents of these metals varied slightly in the liquid products under different experimental conditions. Excess Cr and Ni that did not originate from lignite were found in the residues, owing to reactor corrosion during lignite SCWG. Higher temperatures alleviated corrosion, whereas higher pressures and equivalence ratios (ER) had the opposite effect. None of the heavy metals were detected in the gas phase under the experimental conditions used in the present study. The correlation between the distributions of heavy metals and the experimental conditions were also studied. The transformation pathways of Pb, Cd, Mn, Cu, and Zn during SCWG were deduced according to the experimental results.

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

From conceptual model to remediation: bioavailability, a key to clean up heavy metal contaminated soils.

Science.gov (United States)

Petruzzelli, Gianniantonio; Pedron, Francesca; Pezzarossa, Beatrice

2013-04-01

Processes of metal bioavailability in the soil To know the bioavailability processes at site specific levels is essential to understand in detail the risks associated with pollution, and to support the decision-making process, i.e. description of the conceptual model and choice of clean up technologies. It is particularly important to assess how chemical, physical and biological processes in the soil affect the reactions leading to adsorption, precipitation or release of contaminants. The measurement of bioavailability One of the main difficulties in the practical application of the bioavailability concept in soil remediation is the lack of consensus on the method to be used to measure bioavailability. The best strategy is to apply a series of tests to assess bioavailability, since no applicable method is universally valid under all conditions. As an example, bioavailability tests for phytotechnology application should consider two distinct aspects: a physico-chemical driven solubilization process and a physiologically driven uptake process. Soil and plant characteristics strongly influence bioavailability. Bioavailability as a tool in remediation strategies Bioavailability can be used at all stages in remediation strategies: development of the conceptual model, evaluation of risk assessment, and selection of the best technology, considering different scenarios and including different environmental objectives. Two different strategies can be followed: the reduction and the increase of bioavailability. Procedures that reduce bioavailability aim to prevent the movement of pollutants from the soil to the living organisms, essentially by: i) removal of the labile phase of the contaminant, i.e. the fraction which is intrinsic to the processes of bioavailability (phytostabilization); ii) conversion of the labile fraction into a stable fraction (precipitation or adsorption); iii) increase of the resistance to mass transfer of the contaminants (inertization). Procedures

Total concentration and speciation of heavy metals in biosolids from urban origin; Concentracion total y especiacion de metales pesados en biosolidos de origen urbano origin

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Flores, Eduardo [Laboratorio de Ingenieria Ambiental, Instituto Tecnologico de Puebla, Puebla, Puebla (Mexico)]. E-mail: egonz1962@yahoo.com.mx; Tornero Campante, Mario Alberto [Colegio de Postgraduados - Campus Puebla, San Pedro Cholula, Puebla (Mexico); Angeles Cruz, Yolanda [Laboratorio de Ingenieria Ambiental, Instituto Tecnologico de Puebla, Puebla, Puebla (Mexico); Bonilla y Fernandez, Noemi [Departamento de Agroecologia y Ambiente, Instituto de Ciencias - Benemerita Universidad Autonoma de Puebla, Puebla, Puebla (Mexico)

2009-02-15

The analysis of heavy metals is a very important task to asses the potential environmental and health risk associated with biosolids deposition in agricultural soil. However, it is widely accepted that determination of total concentration of heavy metals does not give an accurate estimation of the potential environmental impact. So, it is necessary to apply speciation studies to obtain suitable information about their bioavailability. This study was carried out on sewage sludge samples collected in a municipal waste-water treatment plant, located in Puebla City (Mexico). They are used for amendment agricultural soil. The speciation of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) was made using a sequential extraction procedure. The aim was to determine their concentration in bioavailability fractions. It was got the total concentration of heavy metals using acid digestion in a closed system and was determined with atomic absorption spectrometry. The total concentrations of heavy metals were lower than that established by Mexican legislation. The heavy metals are mainly associated with the mineral fraction and organic matter and consequently they show low bioavailability. [Spanish] El analisis de metales pesados es una actividad importante cuando se quiere valorar el potencial riesgo ambiental y de salud asociado con la utilizacion de biosolidos en suelos agricolas. Sin embargo, es ampliamente aceptado que la determinacion del contenido total no da una valoracion apropiada del impacto ambiental causado. Por lo tanto, es necesario realizar estudios de especiacion para obtener informacion mas detallada sobre su biodisponibilidad. Este estudio se llevo a cabo con muestras de lodos residuales producidos en una planta de tratamiento de aguas residuales ubicada en la ciudad de Puebla (Mexico). Estos biosolidos son utilizados para enmendar suelos agricolas. La especiacion de metales pesados (Cd, Cr, Cu, Ni, Pb y Zn) se realizo usando un procedimiento de extraccion secuencial

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

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.

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.

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.

Heavy metal in sediments of Ziya River in northern China: distribution, potential risks, and source apportionment.

Science.gov (United States)

Zhu, Xiaolei; Shan, Baoqing; Tang, Wenzhong

2016-12-01

The concentration partitioning between the sediment particle and the interstitial water phase plays an important role in controlling the toxicity of heavy metals in aquatic systems. The aim of this study was to assess the sediment quality in a polluted area of the Ziya River, Northern China. The contamination potential and bioavailability of six metals were determined from the concentrations of total metals and the bioavailable fractions. The results showed that the concentrations of Cr, Cu, Ni, Zn, and Pb exceeded the probable effect concentration at several sites. The high geoaccumulation indices showed that the sediments were seriously contaminated by Cd. The ratio of acid-volatile sulfide (AVS) to simultaneously extracted metal (SEM) was higher than 1, which indicated that the availability of metals in sediments was low. The risk assessment of interstitial waters confirmed that there was little chance of release of metals associated with acid-volatile sulfide into the water column. Values of the interstitial water criteria toxicity unit indicated that none of the concentrations of the studied metals exceeded the corresponding water quality thresholds of the US Environmental Protection Agency. Positive matrix factorization showed that the major sources of metals were related to anthropogenic activities. Further, if assessments are based on total heavy metal concentrations, the toxicity of heavy metals in sediment may be overestimated.

Evaluation of biochars from different stock materials as carriers of bacterial strain for remediation of heavy metal-contaminated soil

OpenAIRE

Wang, Ting; Sun, Hongwen; Ren, Xinhao; Li, Bing; Mao, Hongjun

2017-01-01

Two kinds of biochars, one derived from corn straw and one from pig manure, were studied as carriers of a mutant genotype from Bacillus subtilis (B38) for heavy metal contaminated soil remediation. After amendment with biochar, the heavy metal bioavailability decreased. Moreover, the heavy metal immobilization ability of the biochar was enhanced by combining it with B38. The simultaneous application of B38 and pig manure-derived biochar exhibited a superior effect on the promotion of plant gr...

Data on heavy metals and selected anions in the Persian popular herbal distillates

Directory of Open Access Journals (Sweden)

Mozhgan Keshtkar

2016-09-01

Full Text Available In this data article, we determined the concentration levels of heavy metals including Pb, Co, Cd, Mn, Mg, Fe and Cu as well as selected anions including NO3− , NO2−, PO4−3 and SO4−2 in the most used and popular herbal distillates in Iran. It is well known that heavy metals may pose a serious health hazard due to their bioaccumulation throughout the trophic chain (“Heavy metals (Cd, Cu, Ni and Pb content in two fish species of Persian Gulf in Bushehr Port, Iran” (Dobaradaran et al., 2013 [1]; “Comparative investigation of heavy metal, trace, and macro element contents in commercially valuable fish species harvested off from the Persian Gulf” (Abadi et al., 2015 [2] as well as some other environmental pollutions, “Assessment of sediment quality based on acid-volatile sulfide and simultaneously extracted metals in heavily industrialized area of Asaluyeh, Persian Gulf: concentrations, spatial distributions, and sediment bioavailability/toxicity” (Arfaeinia et al., 2016 [3]. The concentration levels of heavy metals and anions in herbal distillates samples were determined using flame atomic absorption spectrometry (FAAS, Varian AA240, Australia and a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK respectively. Keywords: Daily intake, Herbal distillates, Heavy metals, Selected anions

Bioavailability of Metal Ions and Evolutionary Adaptation

Directory of Open Access Journals (Sweden)

Rolando P. Hong Enriquez

2012-10-01

Full Text Available The evolution of life on earth has been a long process that began nearly 3,5 x 109 years ago. In their initial moments, evolution was mainly influenced by anaerobic environments; with the rise of O2 and the corresponding change in bioavailability of metal ions, new mechanisms of survival were created. Here we review the relationships between ancient atmospheric conditions, metal ion bioavailability and adaptation of metals homeostasis during early evolution. A general picture linking geochemistry, biochemistry and homeostasis is supported by the reviewed literature and is further illustrated in this report using simple database searches.

Speciation and bioavailability of lead in complementary medicines

International Nuclear Information System (INIS)

Bolan, S.; Naidu, R.; Kunhikrishnan, A.; Seshadri, B.; Ok, Y.S.; Palanisami, T.; Dong, M.; Clark, I.

2016-01-01

Complementary medicines have associated risks which include toxic heavy metal(loid) and pesticide contamination. The objective of this study was to examine the speciation and bioavailability of lead (Pb) in selected complementary medicines. Six herbal and six ayurvedic medicines were analysed for: (i) total heavy metal(loid) contents including arsenic (As), cadmium (Cd), Pb and mercury (Hg); (ii) speciation of Pb using sequential fractionation and extended x-ray absorption fine structure (EXAFS) techniques; and (iii) bioavailability of Pb using a physiologically-based in vitro extraction test (PBET). The daily intake of Pb through the uptake of these medicines was compared with the safety guidelines for Pb. The results indicated that generally ayurvedic medicines contained higher levels of heavy metal(loid)s than herbal medicines with the amount of Pb much higher than the other metal(loid)s. Sequential fractionation indicated that while organic-bound Pb species dominated the herbal medicines, inorganic-bound Pb species dominated the ayurvedic medicines. EXAFS data indicated the presence of various Pb species in ayurvedic medicines. This implies that Pb is derived from plant uptake and inorganic mineral input in herbal and ayurvedic medicines, respectively. Bioavailability of Pb was higher in ayurvedic than herbal medicines, indicating that Pb added as a mineral therapeutic input is more bioavailable than that derived from plant uptake. There was a positive relationship between soluble Pb fraction and bioavailability indicating that solubility is an important factor controlling bioavailability. The daily intake values for Pb as estimated by total and bioavailable metal(loid) contents are likely to exceed the safe threshold level in certain ayurvedic medicines. This research demonstrated that Pb toxicity is likely to result from the regular intake of these medicines which requires further investigation. - Highlights: • Pb species in complementary medicines was

Application of SEM/EDS to environmental geochemistry of heavy metals

Directory of Open Access Journals (Sweden)

Mateja Gosar

2009-06-01

Full Text Available Heavy metals represent a ubiquitous constituent of the near-surface environment, present in widely varyingconcentrations that typically have little impact on human behaviour and health. However, the mining of metals anduse of these metals in industrial processes has produced significant anthropogenic inputs of metals to both localand global environments. As such, a rigorous overview of the current accumulation of heavy metals and knowledgeof mineralogy of heavy metal-bearing phases is important for understanding their stability, solubility, mobility,bioavailability and toxicity. These data are of fundamental importance for environmental risk assessment and evaluationof future scenarios. Since conventional geochemical analyses provide limited information, other analyticalmethods have to be utilized for the characterisation of heavy metal-bearing phases. Significant analytical methodfor identification and characterisation of heavy metals in environmental media is a scanning electron microscopecoupled with energy dispersive X-ray spectrometer (SEM/EDS, an apparatus for qualitative and semi-quantitative chemical analysis at microne level, newly introduced to Geological Survey of Slovenia. Use of SEM/EDS was already introduced to environmental studies world-wide. In Slovenia, SEM/EDS analyses of environmental media werefirstly carried out on the Meža River stream sediments and snow deposits from Ljubljana urban area.Heavy metal-bearing phases in the Meža River stream sediments were apportioned to three source areas: Mežica mining/smelting area (geogenic-technogenic origin, Ravne ironworks area (technogenic origin and the Meža River catchment area (geogenic origin, which corresponds to data obtained by conventional geochemical and multivariate statistical methods. Airborne particles, identified in urban snow deposits, were interpreted as geogenic particles, represented by fragments of heavy metal-bearing minerals, and technogenic particles that

Data on heavy metals and selected anions in the Persian popular herbal distillates.

Science.gov (United States)

Keshtkar, Mozhgan; Dobaradaran, Sina; Soleimani, Farshid; Karbasdehi, Vahid Noroozi; Mohammadi, Mohammad Javad; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji

2016-09-01

In this data article, we determined the concentration levels of heavy metals including Pb, Co, Cd, Mn, Mg, Fe and Cu as well as selected anions including [Formula: see text] , [Formula: see text], [Formula: see text] and [Formula: see text] in the most used and popular herbal distillates in Iran. It is well known that heavy metals may pose a serious health hazard due to their bioaccumulation throughout the trophic chain ("Heavy metals (Cd, Cu, Ni and Pb) content in two fish species of Persian Gulf in Bushehr Port, Iran" (Dobaradaran et al., 2013) [1]; "Comparative investigation of heavy metal, trace, and macro element contents in commercially valuable fish species harvested off from the Persian Gulf" (Abadi et al., 2015) [2]) as well as some other environmental pollutions, "Assessment of sediment quality based on acid-volatile sulfide and simultaneously extracted metals in heavily industrialized area of Asaluyeh, Persian Gulf: concentrations, spatial distributions, and sediment bioavailability/toxicity" (Arfaeinia et al., 2016) [3]. The concentration levels of heavy metals and anions in herbal distillates samples were determined using flame atomic absorption spectrometry (FAAS, Varian AA240, Australia) and a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK) respectively.

Bioavailability and Bioaccumulation of Metal-Based Engineered Nanomaterials in Aquatic Environments

DEFF Research Database (Denmark)

Luoma, Samuel; Khan, Farhan R.; Croteau, Marie-Noelle

2014-01-01

Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me......-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex...... interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains...

Behavior of solid matters and heavy metals during conductive drying process of sewage sludge

Directory of Open Access Journals (Sweden)

Jianping Luo

2016-12-01

Full Text Available Behavior of solid matters and heavy metals during conductive drying process of sewage sludge was evaluated in a sewage sludge disposal center in Beijing, China. The results showed most of solid matters could be retained in the dried sludge after drying. Just about 3.1% of solid matters were evaporated with steam mainly by the form of volatile fatty acids. Zn was the dominant heavy metal in the sludge, followed by Cu, Cr, Pb, Ni, Hg, and Cd. The heavy metals in the condensate were all below the detection limit except Hg. Hg in the condensate accounted for less than 0.1% of the total Hg. It can be concluded that most of the heavy metals are also retained in the dried sludge during the drying process, but their bioavailability could be changed significantly. The results are useful for sewage sludge utilization and its condensate treatment.

Effects of biochar and Arbuscular mycorrhizae on bioavailability of potentially toxic elements in an aged contaminated soil

International Nuclear Information System (INIS)

Qiao, Yuhui; Crowley, David; Wang, Kun; Zhang, Huiqi; Li, Huafen

2015-01-01

Biochar pyrolyzed from corn stalks at 300 °C/500 °C and arbuscular mycorrhizae (AMF) were examined independently and in combination as possible treatments for soil remediation contaminated with Cd, Cr, Ni, Cu, Pb, Zn after 35 years following land application of sewage sludge in the 1970s. The results showed that biochar significantly decreased the heavy metal concentrations and their bioavailability for plants, and both biochars had similar such effects. AMF inoculation of corn plants had little effect on heavy metal bioavailability in either control or biochar amended soil, and no interaction between biochar and AMF was observed. Changes in DTPA extractable metals following biochar addition to soil were correlated with metal uptake by plants, whereas pore water metal concentrations were not predictive indicators. This research demonstrates positive benefits from biochar application for contaminated soil remediation, but remain ambiguous with regard to the benefits of simultaneous AMF inoculation on reduction of heavy metal bioavailability. - Highlights: • Biochar pyrolyzed from corn stalks at 300 °C/500 °C can increase the biomass of corn growing in a heavily contaminated soil. • Biochar could significantly decrease bioavailability of heavy metals (Cd, Cr, Ni, Cu, Zn) for plants. • Effects were not augmented by the addition of AMF although the production of glomalin is promoted by biochars. • AMF had not reduced bioavailability of PTEs, no significant interaction between biochar and AMF inoculation was observed. - Biochar could significantly decrease bioavailability of heavy metals (Cd, Cr, Ni, Cu, Zn) for plants, but AMF had little such effects, biochar and AMF interaction is not valid.

Combined action of heavy metals in soils sustaining corn and sorghum: assessment methods, phyto remediation as an option and education strategies

International Nuclear Information System (INIS)

Hernandez, A. J.; Alexis, S.; Pastor, J.

2009-01-01

Heavy metals generated through geochemical processes in some tropical ecosystems, besides affecting the productivity of the systems, could also affect human health. Based on this hypothesis, we set out to assess the bioavailability of heavy metals to these crops used as a main food source or component of fodder. (Author)

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.

Bioavailability of metals-trace in sediments: a review

International Nuclear Information System (INIS)

Rodrigues, Rafaela E. de A.V.; Souza, Vivianne Lucia Bormann; Lima, Vanessa Lemos de; Hazin, Clovis Abrahao

2014-01-01

The chemical association of metals in sediments provides an indication of its release by physical, chemical and biological processes, with toxic effects under certain environmental conditions. Knowing about their chemical bonds in sediments, can recognize specific sources of pollution, and speciation of trace metals is important for bioavailability and toxicity to animals and plants. The accumulation of these particles in the sediment occur by the following mechanisms: a) adsorption to the finest particles; b) precipitating of the element in the form of compounds; c) co-precipitating of the element with iron and manganese oxides; d) complexation with organic matter; e) incorporation into the crystal lattice of minerals. Currently, five phases are considered when studying the bioavailability of trace elements in sediments: a) the exchangeable phase, MgCl 2 (causes saltiness change); b) leachable phase, (acetic acid causes pH change); c) reducible phase (hydroxylamine hydrochloride causes release of the bound metals linked to Fe and Mn oxides); d) oxidized phase, the peroxide hydrogen (cause the degradation of organic matter); e) the residual pseudo-phase, the aqua regia (cause release of metals associated to minerals). The first three phases are considered the most bioavailable. In the last two fractions, the metals are linked to sediment constituents and not bioavailable. The organic phase is relatively stable and the metal present therein are removed under oxidative conditions. Metals present in the pseudo-phase residual measure the degree of environmental pollution, since great amount of metals at this stage indicates a lower degree of pollution

Enhanced bioavailable contaminant stripping (EBCS): metal bioavailability for evaluation of phytoextraction success

OpenAIRE

Petruzzelli, Gianniantonio; Pedron, Francesca; Gorini, Francesca; Pezzarossa, Beatrice; Tassi, Eliana; Barbafieri, Meri

2013-01-01

Phytoextraction may be applied at field scale when the removal of bioavailable metals is the specific target of the technology. Residual metals in soil can be considered substantially inert or to be evaluated by site specific risk analysis.

Particle size distribution and characteristics of heavy metals in road-deposited sediments from Beijing Olympic Park.

Science.gov (United States)

Li, Haiyan; Shi, Anbang; Zhang, Xiaoran

2015-06-01

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments (RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size (Pb>Cu>Zn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: Cd>Zn≈Pb>Cu. Copyright © 2015. Published by Elsevier B.V.

Chemical Speciation and Quantitative Evaluation of Heavy Metal Pollution Hazards in Two Army Shooting Range Backstop Soils.

Science.gov (United States)

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

2016-02-01

The chemical speciation and ecological risk assessment of heavy metals in two shooting range backstop soils in Korea were studied. Both soils were highly contaminated with Cd, Cu, Pb, and Sb. The chemical speciation of heavy metals reflected the present status of contamination, which could help in promoting management practices. We-rye soil had a higher proportion of exchangeable and carbonate bound metals and water-extractable Cd and Sb than the Cho-do soil. Bioavailable Pb represented 42 % of the total Pb content in both soils. A significant amount of Sb was found in the two most bioavailable fractions, amounting to ~32 % in the soil samples, in good agreement with the batch leaching test using water. Based on the values of ecological risk indices, both soils showed extremely high potential risk and may represent serious environmental problems.

Fungal inoculation and elevated CO2 mediate growth of Lolium mutiforum and Phytolacca americana, metal uptake, and metal bioavailability in metal-contaminated soil: evidence from DGT measurement.

Science.gov (United States)

Song, Ningning; Wang, Fangli; Zhang, Changbo; Tang, Shirong; Guo, Junkang; Ju, Xuehai; Smith, Donald L

2013-01-01

Fungal inoculation and elevated CO2 may mediate plant growth and uptake of heavy metals, but little evidence from Diffusive Gradients in Thin-films (DGT) measurement has been obtained to characterize the process. Lolium mutiforum and Phytolacca americana were grown at ambient and elevated CO2 on naturally Cd and Pb contaminated soils inoculated with and without Trichoderma asperellum strain C3 or Penicillium chrysogenum strain D4, to investigate plant growth, metal uptake, and metal bioavailability responses. Fungal inoculation increased plant biomass and shoot/root Cd and Pb concentrations. Elevated CO2 significantly increased plants biomass, but decreased Cd and Pb concentrations in shoot/root to various extents, leading to a metal dilution phenomenon. Total Cd and Pb uptake by plants, and DGT-measured Cd and Pb concentrations in rhizosphere soils, were higher in all fungal inoculation and elevated CO2 treatments than control treatments, with the combined treatments having more influence than either treatment alone. Metal dilution phenomenon occurred because the increase in DGT-measured bioavailable metal pools in plant rhizosphere due to elevated CO2 was unable to match the increase in requirement for plant uptake of metals due to plant biomass increase.

Enhanced Bioavailable Contaminant Stripping (EBCS: metal bioavailability for evaluation of phytoextraction success

Directory of Open Access Journals (Sweden)

Petruzzelli G.

2013-04-01

Full Text Available Phytoextraction may be applied at field scale when the removal of bioavailable metals is the specific target of the technology. Residual metals in soil can be considered substantially inert or to be evaluated by site specific risk analysis.

Multivariate statistical study of heavy metal enrichment in sediments of the Pearl River Estuary

International Nuclear Information System (INIS)

Liu, W.X.; Li, X.D.; Shen, Z.G.; Wang, D.C.; Wai, O.W.H.; Li, Y.S.

2003-01-01

Multivariate statistical analysis identified the heavy metal accumulation layers of sediment profiles and showed the various sources of metals in the estuary. - The concentrations and chemical partitioning of heavy metals in the sediment cores of the Pearl River Estuary were studied. Based on Pearson correlation coefficients and principal component analysis results, Al was selected as the concentration normalizer for Pb, while Fe was used as the normalizing element for Co, Cu, Ni and Zn. In each profile, sections with metal concentrations exceeding the upper 95% prediction interval of the linear regression model were regarded as metal enrichment layers. The heavy metal accumulation mainly occurred at sites in the western shallow water areas and east channel, which reflected the hydraulic conditions and influence from riparian anthropogenic activities. Heavy metals in the enrichment sections were evaluated by a sequential extraction method for possible chemical forms in sediments. Since the residual, Fe/Mn oxides and organic/sulfide fractions were dominant geochemical phases in the enriched sections, the bioavailability of heavy metals in sediments was generally low. The 206 Pb/ 207 Pb ratios in the metal-enriched sediment sections also revealed the influence of anthropogenic sources. The spatial distribution of cumulative heavy metals in the sediments suggested that the Zn and Cu mainly originated from point sources, while the Pb probably came from non-point sources in the estuary

Pollution control and metal resource recovery for low grade automobile shredder residue: a mechanism, bioavailability and risk assessment.

Science.gov (United States)

Singh, Jiwan; Lee, Byeong-Kyu

2015-04-01

Automobile shredder residue (ASR) is considered as hazardous waste in Japan and European countries due to presence of heavy metals. This study was carried on the extraction characteristics of heavy metals (Mn, Fe, Ni, and Cr) from automobile shredder residue (ASR). The effects of pH, temperature, particle size, and liquid/solid ratio (L/S) on the extraction of heavy metals were investigated. The recovery rate of Mn, Fe, Ni, and Cr increased with increasing extraction temperature and L/S ratio. The lowest pH 2, the highest L/S ratio, and the smallest particle size showed the highest recovery of heavy metals from ASR. The highest recovery rates were in the following order: Mn > Ni > Cr > Fe. Reduction of mobility factor for the heavy metals was observed in all the size fractions after the recovery. The results of the kinetic analysis for various experimental conditions supported that the reaction rate of the recovery process followed a second order reaction model (R(2) ⩾ 0.95). The high availability of water-soluble fractions of Mn, Fe, Ni, and Cr from the low grade ASR could be potential hazards to the environment. Bioavailability and toxicity risk of heavy metals reduced significantly with pH 2 of distilled water. However, water is a cost-effective extracting agent for the recovery of heavy metals and it could be useful for reducing the toxicity of ASR. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced phytoextraction: II. Effect of EDTA and citric acid on heavy metal uptake by Helianthus annuus from a calcareous soil.

Science.gov (United States)

Lesage, E; Meers, E; Vervaeke, P; Lamsal, S; Hopgood, M; Tack, F M G; Verloo, M G

2005-01-01

High biomass producing plant species, such as Helianthus annuus, have potential for removing large amounts of trace metals by harvesting the aboveground biomass if sufficient metal concentrations in their biomass can be achieved However, the low bioavailability of heavy metals in soils and the limited translocation of heavy metals to the shoots by most high biomass producing plant species limit the efficiency of the phytoextraction process. Amendment of a contaminated soil with ethylene diamine tetraacetic acid (EDTA) or citric acid increases soluble heavy metal concentrations, potentially rendering them more available for plant uptake. This article discusses the effects of EDTA and citric acid on the uptake of heavy metals and translocation to aboveground harvestable plant parts in Helianthus annuus. EDTA was included in the research for comparison purposes in our quest for less persistent alternatives, suitable for enhanced phytoextraction. Plants were grown in a calcareous soil moderately contaminated with Cu, Pb, Zn, and Cd and treated with increasing concentrations of EDTA (0.1, 1, 3, 5, 7, and 10 mmol kg(-1) soil) or citric acid (0.01, 0.05, 0.25, 0.442, and 0.5 mol kg(-1) soil). Heavy metal concentrations in harvested shoots increased with EDTA concentration but the actual amount of phytoextracted heavy metals decreased at high EDTA concentrations, due to severe growth depression. Helianthus annuus suffered heavy metal stress due to the significantly increased bioavailable metal fraction in the soil. The rapid mineralization of citric acid and the high buffering capacity of the soil made citric acid inefficient in increasing the phytoextracted amounts of heavy metals. Treatments that did not exceed the buffering capacity of the soil (heavy metal concentrations. Treatments with high concentrations resulted in a dissolution of the carbonates and compaction of the soil. These physicochemical changes caused growth depression of Helianthus annuus. EDTA and citric

Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico.

Science.gov (United States)

Perry, Harriet; Isphording, Wayne; Trigg, Christine; Riedel, Ralf

2015-12-30

The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Soil heavy metals

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

The possibility to use the Eichhornia crassipes plant in the estimation of heavy metal levels in the Almendares river, Havana Cuba

International Nuclear Information System (INIS)

Columbie, I.; Olivares, S.; Lima, L.; De La Rosa, D.

2005-01-01

The possibility to use the Eichhornia crassipes plant in the estimation of heavy metal levels in the Almendares river were evaluated in this paper. Concentration of Cd, Pb, Zn, Cu, Co, Cr and Ni in macrophyte Eichhornia crassipes (Water Jacint) were evaluated at 15 stations during the dry season of 2003 and 2004. In Eichhornia crassipes roots and in the bioavailable fraction of the sediments followed the some spatial trend, showing elevated metal concentration's at the some stations. Highly significant correlation were found for these elements in Eichhornia crassipes roots and in the organic fraction of the sediments, which means that the concentrations of these elements in Eichhornia crassipes are indicative of the bioavailable concentrations in sediments. Three main sources of heavy metal pollution were identified in the basin due to the high concentration of most of the studied metals in the sampling stations, the secondary smelter Antillana de Acero, an important provincial landfill in the street 100 and the Mordazo tributary river. The obtained results show that Eichhornia crassipes could be an interesting monitor of the heavy metal pollution in Almendares River

Evaluation of biochars from different stock materials as carriers of bacterial strain for remediation of heavy metal-contaminated soil.

Science.gov (United States)

Wang, Ting; Sun, Hongwen; Ren, Xinhao; Li, Bing; Mao, Hongjun

2017-09-21

Two kinds of biochars, one derived from corn straw and one from pig manure, were studied as carriers of a mutant genotype from Bacillus subtilis (B38) for heavy metal contaminated soil remediation. After amendment with biochar, the heavy metal bioavailability decreased. Moreover, the heavy metal immobilization ability of the biochar was enhanced by combining it with B38. The simultaneous application of B38 and pig manure-derived biochar exhibited a superior effect on the promotion of plant growth and the immobilization of heavy metals in soil. The plant biomass increased by 37.9% and heavy metal concentrations in the edible part of lettuce decreased by 69.9-96.1%. The polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that pig manure-derived biochar could enhance the proliferation of both exotic B38 and native microbes. These results suggest that B38 carried by pig manure-derived biochar may be a promising candidate for the remediation of soils contaminated by multiple heavy metals.

Speciation of heavy metals in garden soils. Evidences from selective and sequential chemical leaching

Energy Technology Data Exchange (ETDEWEB)

Cheng, Zhongqi; Lee, Leda; Dayan, Sara; Grinshtein, Michael [Brooklyn College of The City Univ. of New York, Brooklyn, NY (United States). Environmental Sciences Analytical Cnter; Shaw, Richard [USDA-NRCS NYC Soil Survey, Staten Island, NY (United States)

2011-06-15

Purpose: Gardening (especially food growing) in urban areas is becoming popular, but urban soils are often very contaminated for historical reasons. There is lack of sufficient information as to the bioavailability of soil heavy metals to plants and human in urban environments. This study examines the relative leachability of Cr, Ni, As, Cd, Zn, and Pb for soils with varying characteristics. The speciation and mobility of these metals can be qualitatively inferred from the leaching experiments. The goal is to use the data to shed some light on their bioavailability to plant and human, as well as the basis for soil remediation. Materials and methods: Selective and sequential chemical leaching methods were both used to evaluate the speciation of Cr, Ni, As, Cd, Zn, and Pb in soil samples collected from New York City residential and community gardens. The sequential leaching experiment followed a standard BCR four-step procedure, while selective leaching involved seven different chemical extractants. Results and discussion: The results from selective and sequential leaching methods are consistent. In general, very little of the heavy metals were found in the easily soluble or exchangeable fractions. Larger fractions of Cd and Zn can be leached out than other metals. Lead appears predominantly in the organic or carbonate fractions, of which {proportional_to} 30-60% is in the easily soluble organic fraction. Most As cannot be leached out by any of the extractants used, but it could have been complicated by the ineffective dissolution of oxides by ammonium hydroxylamine. Ni and Cr were mostly in the residual fractions but some released in the oxidizable fractions. Therefore, the leachability of metals follow the order Cd/Zn > Pb > Ni/Cr. Conclusions: Despite of the controversy and inaccuracy surrounding chemical leaching methods for the speciation of metals, chemical leaching data provide important, general, and easy-to-access information on the mobility of heavy metals

Accounting for metal bioavailability in assessing water quality: A step change?

Science.gov (United States)

Merrington, Graham; Peters, Adam; Schlekat, Christian E

2016-02-01

Bioavailability of metals to aquatic organisms can be considered to be a combination of the physicochemical factors governing metal behavior and the specific pathophysiological characteristics of the organism's biological receptor. Effectively this means that a measure of bioavailability will reflect the exposures that organisms in the water column actually "experience". This is important because it has long been established that measures of total metal in waters have limited relevance to potential environmental risk. The concept of accounting for bioavailability in regard to deriving and implementing environmental water quality standards is not new, but the regulatory reality has lagged behind the development of scientific evidence supporting the concept. Practical and technical reasons help to explain this situation. For example, concerns remain from regulators and the regulated that the efforts required to change existing systems of metal environmental protection that have been in place for over 35 yr are so great as not to be commensurate with likely benefits. However, more regulatory jurisdictions are now considering accounting for metal bioavailability in assessments of water quality as a means to support evidence-based decision-making. In the past decade, both the US Environmental Protection Agency and the European Commission have established bioavailability-based standards for metals, including Cu and Ni. These actions have shifted the debate toward identifying harmonized approaches for determining when knowledge is adequate to establish bioavailability-based approaches and how to implement them. © 2016 SETAC.

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.

Heavy metals pollution status in surface sediments (rivers and artifical lakes, Serbia)

Science.gov (United States)

Sakan, Sanja; Đorđević, Dragana

2017-04-01

Potentially hazardous trace elements, often in literature referred as "heavy metals", are deemed serious pollutants due to their toxicity, persistence and non-degradability in the environment. These elements play an important role in extent of water pollution and threaten the health of populations and ecosystems. As the sink of heavy metals, sediment beds adsorb metals in quantities that are many times higher than those found in the water column in the long-term polluted water environment. It is believed that most of the metal content, as much as 90% in aquatic sediments is bound to sediments. Metal contamination in these sediments could be directly affect the river water quality, resulting in potential consequences to the sensitive lowest levels of the food chain and ultimately to human health. The objective of this research was the evaluation of heavy metal contamination level in sediments of the most important rivers and artificial lakes in Serbia. The heavy metal enrichment in studied sediments was conducted by using: determination of total metal content, sequential extraction procedure for the fractionation of studied elements, quantification of the metal enrichment degree in the sediments by calculating geo-accumulation indices, determination of actual and potential element availability and application of BRAI index for the assessment of heavy metal bioavailability. The sediments were found to be contaminated by heavy metals to various extents, mostly with Cd, Cu, and Zn. The significant variation in heavy metal distribution among samples collected in this large region, encompassing all Serbian watersheds, suggests the selective contamination of sediments by heavy metals. Elevated concentrations of elements in most cases were detected in samples of river sediments, since artificial lake reservoirs are usually built in rural areas, where the less anthropogenic pollution. Rivers often flow through the towns and these water basins less or more loaded

The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

Science.gov (United States)

Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

2017-01-01

This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

The impact of metal transport processes on bioavailability of free and complex metal ions in methanogenic granular sludge

NARCIS (Netherlands)

Bartacek, J.; Fermoso, F.G.; Vergeldt, F.; Gerkema, E.; Maca, J.; As, van H.; Lens, P.N.L.

2012-01-01

Bioavailability of metals in anaerobic granular sludge has been extensively studied, because it can have a major effect on metal limitation and metal toxicity to microorganisms present in the sludge. Bioavailability of metals can be manipulated by bonding to complexing molecules such as

Fixation and partitioning of heavy metals in slag after incineration of sewage sludge.

Science.gov (United States)

Chen, Tao; Yan, Bo

2012-05-01

Fixation of heavy metals in the slag produced during incineration of sewage sludge will reduce emission of the metals to the atmosphere and make the incineration process more environmentally friendly. The effects of incineration conditions (incineration temperature 500-1100°C, furnace residence time 0-60min, mass fraction of water in the sludge 0-75%) on the fixation rates and species partitioning of Cd, Pb, Cr, Cu, Zn, Mn and Ni in slag were investigated. When the incineration temperature was increased from 500 to 1100°C, the fixation rate of Cd decreased from 87% to 49%, while the fixation rates of Cu and Mn were stable. The maximum fixation rates for Pb and Zn and for Ni and Cr were reached at 900 and 1100°C, respectively. The fixation rates of Cu, Ni, Cd, Cr and Zn decreased as the residence time increased. With a 20min residence time, the fixation rates of Pb and Mn were low. The maximum fixation rates of Ni, Mn, Zn, Cu and Cr were achieved when the mass fraction of water in the sludge was 55%. The fixation rate of Cd decreased as the water mass fraction increased, while the fixation rate of Pb increased. Partitioning analysis of the metals contained in the slag showed that increasing the incineration temperature and residence time promoted complete oxidation of the metals. This reduced the non-residual fractions of the metals, which would lower the bioavailability of the metals. The mass fraction of water in the sludge had little effect on the partitioning of the metals. Correlation analysis indicated that the fixation rates of heavy metals in the sludge and the forms of heavy metals in the incinerator slag could be controlled by optimization of the incineration conditions. These results show how the bioavailability of the metals can be reduced for environmentally friendly disposal of the incinerator slag. Copyright © 2011 Elsevier Ltd. All rights reserved.

Heavy metal jako subkultura

OpenAIRE

KOUTNÁ, Daniela

2016-01-01

This bachelor thesis deals with heavy metal subculture. Its aim is to introduce the most important branches and to show broadness of heavy metal. This bachelor thesis describes development and history, briefly shows Czech heavy metal history alongside with the biggest and most popular Czech heavy metal festivals. It shows the most dressing concerns of society against this style.

Albatross as Sentinels of Heavy Metal Pollution: Local and Global Factors

Directory of Open Access Journals (Sweden)

Bank M.S.

2014-07-01

Full Text Available Heavy metal pollution in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists over the extent to which mercury in biota may have resulted from increases in anthropogenic emissions over time. Albatrosses, including those inhabiting the North Pacific, are wide-ranging, long-lived, keystone, avian predators. Consequently, they serve as ideal sentinel species for investigating the effects of historical and contemporary pollution as well as local and global factors related to heavy metal exposure, bioaccumulation, and ecotoxicological risk. To date, high levels of mercury and lead have been documented in albatross species throughout the Pacific. To address biotic exposure to these multiple stressors, here we synthesize and conduct meta-analyses of total mercury, methylmercury, and lead exposure data in Black-footed albatross (Phoebastria nigripes and Laysan albatross (Phoebastria immutabilis. Our approach includes data from the field and literature, and for total mercury and methyl mercury, we use measurements from museum feathers spanning the past 130 years for Black-Footed albatross. We discuss the use and application of stable isotopes (δ15N and δ13C as a way to control for temporal changes in trophic structure and diet and we demonstrate the importance of conducting speciation analyses for mercury to account for historical, curator-mediated, inorganic mercury contamination of specimens. Our data showed higher levels of inorganic mercury in older specimens of Black-Footed albatross as well as two non-pelagic species (control samples lacking historical sources of bioavailable mercury exposure, which suggests that studies on bioaccumulation should measure methylmercury rather than total mercury when utilizing museum collections. Changes in methylmercury levels in Black-Footed albatross were consistent with historical global and recent regional

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.

Bioavailability in rats of metal adsorbed to soils

International Nuclear Information System (INIS)

Rubenstein, R.; Griffin, S.; Irene, S.; DeRosa, C.; Choudhury, H.

1990-01-01

The toxicity of metals to humans and animals has been well documented, however little data are available on the physiological bioavailability of metals from various soil types. These studies were designed to assess the bioavailability of sodium 75 selenate (NaS), 63 nickel chloride (NiCl) and 109 cadmium chloride (CdCl) adsorbed to sand or clay loam in rats. Each test compound was administered in seven dose groups: Group 1 - intravenously, Group 2 and 3 - oral aqueous solution by gavage, Groups 4-7 - aqueous suspension adsorbed to each soil type by gavage. Blood was collected from the jugular vein at intervals up to 48 hours post dosing and analyzed for radio-activity. Both NiCl and CdCl were poorly adsorbed from the soils. Approximately 3% of the CdCl bound to sand and 1.5% of the NiCl bound to clay loam were absorbed into the bloodstream. Approximately 0.5% and 0.1% of the CdCl bound to sand and clay, respectively were absorbed. NaS was well absorbed following oral administration with approximately 85% of the compound bound to sand and 94% bound to clay being absorbed into the blood. Bioavailability of metals from soil appears to be primarily affected by the ionic state of the metal. Anions, such as selenium, are more mobile in an acid environment and may leach more readily from soil. Cations, such as Ni and Cd may bind to soil more tightly, thus soil type becomes a factor affecting bioavailability

Heavy Metal Stress, Signaling, and Tolerance Due to Plant-Associated Microbes: An Overview

Science.gov (United States)

Tiwari, Shalini; Lata, Charu

2018-01-01

Several anthropogenic activities including mining, modern agricultural practices, and industrialization have long-term detrimental effect on our environment. All these factors lead to increase in heavy metal concentration in soil, water, and air. Soil contamination with heavy metals cause several environmental problems and imparts toxic effect on plant as well as animals. In response to these adverse conditions, plants evolve complex molecular and physiological mechanisms for better adaptability, tolerance, and survival. Nowadays conventional breeding and transgenic technology are being used for development of metal stress resistant varieties which, however, are time consuming and labor intensive. Interestingly the use of microbes as an alternate technology for improving metal tolerance of plants is gaining momentum recently. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices. Interaction of plants with soil microorganisms can play a vital role in acclimatizing plants to metalliferous environments, and can thus be explored to improve microbe-assisted metal tolerance. Plant-associated microbes decrease metal accumulation in plant tissues and also help to reduce metal bioavailability in soil through various mechanisms. Nowadays, a novel phytobacterial strategy, i.e., genetically transformed bacteria has been used to increase remediation of heavy metals and stress tolerance in plants. This review takes into account our current state of knowledge of the harmful effects of heavy metal stress, the signaling responses to metal stress, and the role of plant-associated microbes in metal stress tolerance. The review also highlights the challenges and opportunities in this continued area of research on plant–microbe–metal interaction. PMID:29681916

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

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.

Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

International Nuclear Information System (INIS)

Amaral, Andre; Soto, Manu; Cunha, Regina; Marigomez, Ionan; Rodrigues, Armindo

2006-01-01

Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former. - In earthworms, differences in the chloragogenous tissue morphometry may be related to the bioavailability of metals in soils

Effect of addition of sewage sludge and coal sludge on bioavailability of selected metals in the waste from the zinc and lead industry.

Science.gov (United States)

Sobik-Szołtysek, Jolanta; Wystalska, Katarzyna; Grobelak, Anna

2017-07-01

This study evaluated the content of bioavailable forms of selected heavy metals present in the waste from Zn and Pb processing that can potentially have an effect on the observed difficulties in reclamation of landfills with this waste. The particular focus of the study was on iron because its potential excess or deficiency may be one of the causes of the failure in biological reclamation. The study confirmed that despite high content of total iron in waste (mean value of 200.975gkg -1 ), this metal is present in the forms not available to plants (mean: 0.00009gkg -1 ). The study attempted to increase its potential bioavailability through preparation of the mixtures of this waste with additions in the form of sewage sludge and coal sludge in different proportions. Combination of waste with 10% of coal sludge and sewage sludge using the contents of 10%, 20% and 30% increased the amounts of bioavailable iron forms to the level defined as sufficient for adequate plant growth. The Lepidum sativum test was used to evaluate phytotoxicity of waste and the mixtures prepared based on this waste. The results did not show unambiguously that the presence of heavy metals in the waste had a negative effect on the growth of test plant roots. Copyright © 2017 Elsevier Inc. All rights reserved.

Caddisflies as biomonitors identifying thresholds of toxic metal bioavailability that affect the stream benthos

International Nuclear Information System (INIS)

Rainbow, Philip S.; Hildrew, Alan G.; Smith, Brian D.; Geatches, Tim; Luoma, Samuel N.

2012-01-01

It has been proposed that bioaccumulated concentrations of toxic metals in tolerant biomonitors be used as indicators of metal bioavailability that could be calibrated against the ecological response to metals of sensitive biotic assemblages. Our hypothesis was that metal concentrations in caddisfly larvae Hydropsyche siltalai and Plectrocnemia conspersa, as tolerant biomonitors, indicate metal bioavailability in contaminated streams, and can be calibrated against metal-specific ecological responses of mayflies. Bioaccumulated concentrations of Cu, As, Zn and Pb in H. siltalai from SW English streams were related to the mayfly assemblage. Mayflies were always sparse where bioavailabilities were high and were abundant and diverse where bioavailabilities of all metals were low, a pattern particularly evident when the combined abundance of heptageniid and ephemerellid mayflies was the response variable. The results offer promise that bioaccumulated concentrations of metals in tolerant biomonitors can be used to diagnose ecological impacts on stream benthos from metal stressors. - Highlights: ► Metal concentrations in caddisfly larvae can be calibrated against mayfly ecological responses. ► Cu, As, Zn and Pb concentrations in Hydropsyche siltalai were related to stream mayfly assemblages. ► Mayflies were sparse in high metal bioavailabilities, and abundant in low bioavailabilities. ► Joint heptageniid and ephemerellid mayfly abundance was the most sensitive response variable. ► Copper, arsenic and, in one catchment, lead were the primary stressors limiting mayfly abundance. - Accumulated metal concentrations in tolerant biomonitors can be used to detect and diagnose ecological impacts on freshwater stream benthos from metal stressors.

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Science.gov (United States)

Stietiya, Mohammed Hashem; Duqqah, Mohammad; Udeigwe, Theophilus; Zubi, Ruba; Ammari, Tarek

2014-01-01

Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective. PMID:24723833

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Directory of Open Access Journals (Sweden)

Mohammed Hashem Stietiya

2014-01-01

Full Text Available Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1 soil was higher than Wadi Dhuleil (WD1 soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.

Relating metal bioavailability to risk assessment for aquatic species: Daliao River watershed, China

International Nuclear Information System (INIS)

Han, Shuping; Zhang, Ying; Masunaga, Shigeki; Zhou, Siyun; Naito, Wataru

2014-01-01

The spatial distribution of metal bioavailability (Ni, Cu, Zn, and Pb) was first evaluated within the waters of Daliao River watershed, using the diffusive gradient in thin films (DGT) and chemical equilibrium models. To assess potential risks associated with metal bioavailability, site-specific 95% protection levels (HC5), risk characterizations ratios (RCR) and ratios of DGT-labile/HC5 were derived, using species sensitivity distribution (SSD). The highest bioavailability values for metals were recorded in the main channel of the Daliao River, followed by the Taizi River. Dynamic concentrations predicted by WHAM 7.0 and NICA-Donnan for Cu and Zn agreed well with DGT results. The estuary of the Daliao River was found to have the highest risks related to Ni, Cu, and Zn. The number of sites at risk increased when considering the total toxicity of Ni, Cu, and Zn. - Highlights: • Spatial variation in metal bioavailability within Daliao River watershed was studied. • WHAM 7.0 and NICA-Donnan examined the differences in predicting metal speciation. • Bioavailability values of metals were highest in main channel of the Daliao River. • Site-specific 95% protection levels (HC5)/risk variations were assessed using SSD. • Maximum risks from Ni, Cu, and Zn occurred in the estuary of the Daliao River. - The highest bioavailability values and the highest risks of metals were found in the estuary of the Daliao River

Influence of bacteria on Pb and Zn speciation, mobility and bioavailability in soil: A laboratory study

International Nuclear Information System (INIS)

Wu, S.C.; Luo, Y.M.; Cheung, K.C.; Wong, M.H.

2006-01-01

A soil column experiment was carried out to investigate the effects of inoculation of bacteria on metal bioavailability, mobility and potential leachability through single chemical extraction, consequential extraction and in situ soil solution extraction technologies. Results showed that bacteria inoculated, including Azotobacter chroococcum, Bacillus megaterium and Bacillus mucilaginosus, may pose both positive and negative impacts on bioavailability and mobility of heavy metals in soil, depending on the chemical nature of the metals. The activities of bacteria led to an increase of water dissolved organic carbon (DOC) concentration and a decrease of pH value, which enhanced metal mobility and bioavailability (e.g. an increase of water-soluble and HOAc-soluble Zn). On the other hand, bacteria could immobilize metals (e.g. a great reduction of water-soluble Pb) due to the adsorption by bacterial cell walls and possible sedimentation reactions with phosphate or other anions produced through bacterial metabolism. - Influence of bacterial activities on heavy metal is two-edged

Heavy Metal Stress, Signaling, and Tolerance Due to Plant-Associated Microbes: An Overview

Directory of Open Access Journals (Sweden)

Shalini Tiwari

2018-04-01

Full Text Available Several anthropogenic activities including mining, modern agricultural practices, and industrialization have long-term detrimental effect on our environment. All these factors lead to increase in heavy metal concentration in soil, water, and air. Soil contamination with heavy metals cause several environmental problems and imparts toxic effect on plant as well as animals. In response to these adverse conditions, plants evolve complex molecular and physiological mechanisms for better adaptability, tolerance, and survival. Nowadays conventional breeding and transgenic technology are being used for development of metal stress resistant varieties which, however, are time consuming and labor intensive. Interestingly the use of microbes as an alternate technology for improving metal tolerance of plants is gaining momentum recently. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices. Interaction of plants with soil microorganisms can play a vital role in acclimatizing plants to metalliferous environments, and can thus be explored to improve microbe-assisted metal tolerance. Plant-associated microbes decrease metal accumulation in plant tissues and also help to reduce metal bioavailability in soil through various mechanisms. Nowadays, a novel phytobacterial strategy, i.e., genetically transformed bacteria has been used to increase remediation of heavy metals and stress tolerance in plants. This review takes into account our current state of knowledge of the harmful effects of heavy metal stress, the signaling responses to metal stress, and the role of plant-associated microbes in metal stress tolerance. The review also highlights the challenges and opportunities in this continued area of research on plant–microbe–metal interaction.

Temporal variations of heavy metals levels in Perna viridis, on the Chacopata-Bocaripo lagoon axis, Sucre State, Venezuela.

Science.gov (United States)

Pinto, Rafael; Acosta, Vanessa; Segnini, Mary Isabel; Brito, Leonor; Martínez, Gregorio

2015-02-28

Perna viridis was used as biomonitor to assess heavy metal levels in the Chacopata-Bocaripo lagoon axis, Venezuela, during rain and drought seasons. The mussels were weighed and measured. The metal concentrations were determined by atomic absorption spectrophotometry. For rain period, the order of bioavailability was: Cu>Ni>Mn>Co>Cd>Pb, and for drought: Cu>Mn>Ni>Co>Pb>Cd. The concentrations of Ni, Co, Cd and Pb showed significant differences (P<0.05) in both periods. There was higher metal accumulation during drought season, possibly related to upwelling, since it produces an increase in primary productivity, which translates more food into organisms, making metals bioavailable for mussels. Only Cu and Mn showed significant relationships between the size and metal concentration, during drought period, it may be because of the organisms need for these essential metals in different physiological processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heavy metals in our foodstuffs

Energy Technology Data Exchange (ETDEWEB)

1983-11-01

The special group ''chemistry of food and forensic chemistry'' of the Association of German Analytical Chemists in Munich in 1983 issued a statement on that subject. The publication points out how heavy metals (examples: lead, cadmium and mercury) make their way into the foodstuffs, how many heavy metals are contained in our foodstuffs, which heavy metals are indispensable minerals and which aren't, and which heavy metals are ingested with food. It concludes by discussing how heavy metal contamination of our food can be prevented.

Metal bioavailability in ecological risk assessment of freshwater ecosystems: From science to environmental management.

Science.gov (United States)

Väänänen, Kristiina; Leppänen, Matti T; Chen, XuePing; Akkanen, Jarkko

2018-01-01

Metal contamination in freshwater ecosystems is a global issue and metal discharges to aquatic environments are monitored in order to protect aquatic life and human health. Bioavailability is an important factor determining metal toxicity. In aquatic systems, metal bioavailability depends on local water and sediment characteristics, and therefore, the risks are site-specific. Environmental quality standards (EQS) are used to manage the risks of metals in aquatic environments. In the simplest form of EQSs, total concentrations of metals in water or sediment are compared against pre-set acceptable threshold levels. Now, however, the environmental administration bodies have stated the need to incorporate metal bioavailability assessment tools into environmental regulation. Scientific advances have been made in metal bioavailability assessment, including passive samplers and computational models, such as biotic ligand models (BLM). However, the cutting-edge methods tend to be too elaborate or laborious for standard environmental monitoring. We review the commonly used metal bioavailability assessment methods and introduce the latest scientific advances that might be applied to environmental management in the future. We present the current practices in environmental management in North America, Europe and China, highlighting the good practices and the needs for improvement. Environmental management has met these new challenges with varying degrees of success: the USA has implemented site-specific environmental risk assessment for water and sediment phases, and they have already implemented metal mixture toxicity evaluation. The European Union is promoting the use of bioavailability and BLMs in ecological risk assessment (ERA), but metal mixture toxicity and sediment phase are still mostly neglected. China has regulation only for total concentrations of metals in surface water. We conclude that there is a need for (1) Advanced and up-to-date guidelines and legislation

Albatross as Sentinels of Heavy Metal Pollution: Local and Global Factors

Science.gov (United States)

Sentman, W.; Edwards, S. V.; Vo, A. E.; Bank, M. S.

2012-12-01

Heavy metal pollution in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists over the extent to which mercury in biota may have resulted from increases in anthropogenic emissions over time. Albatrosses, including those inhabiting the North Pacific, are wide-ranging, long-lived, keystone, avian predators. Consequently, they serve as ideal sentinel species for investigating the effects of historical and contemporary pollution as well as local and global factors related to heavy metal bioaccumulation, exposure, and ecotoxicological risk. To date, high levels of mercury and lead have been documented in albatross species throughout the Pacific. To address biotic exposure to these multiple stressors, here we synthesize and conduct meta-analyses of total mercury, methylmercury, and lead exposure data in Black-footed albatross (Phoebastria nigripes) and Laysan albatross (Phoebastria immutabilis). Our approach uses data from the field and literature and for methyl mercury uses museum feathers spanning the past 130 years for Black-Footed albatross. We discuss the use and application of stable isotopes (δ15N and δ13C) as a way to control for temporal changes in trophic structure and diet and the importance of conducting speciation analyses, for mercury, to account for curator mediated inorganic mercury in older specimens. Our data showed higher levels of inorganic mercury in older specimens of Black-Footed albatross as well as two non-pelagic species (control samples) lacking historical sources of bioavailable mercury exposure, which suggests that studies on bioaccumulation should measure methylmercury rather than total mercury when utilizing museum collections. Additionally, at the local scale, previous research has reported that lead paint exposure from buildings was also an important environmental stressor for Laysan albatross, suggesting that albatross species face heavy

Heavy metal levels and solid phase speciation in street dusts of Delhi, India

International Nuclear Information System (INIS)

Banerjee, Anju D.K.

2003-01-01

Although the street dusts of Delhi contain considerably high levels of Cr, Ni, Cu, Cd, Zn and Pb, solid phase speciation results indicate comparatively limited environmental mobility and bioavailability of Ni and Cr. - Street dust samples were collected from three different localities (industrial, heavy traffic and rural) situated in the greater Delhi area of India. The samples analyzed for Cd, Zn, Pb, Ni, Cu, and Cr indicated remarkably high levels of Cr, Ni, and Cu in the industrial area, whilst Pb and Cd did not show any discernible variations between the three localities. A multivariate statistical approach (Principal Component Analysis) was used to define the possible origin of metals in dusts. The street dusts were sequentially extracted so that the solid pools of Cd, Zn, Pb, Ni, Cu, Cr could be partitioned into five operationally defined fractions viz. exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. Metal recoveries in sequential extractions were ±10% of the independently measured total metal concentrations. Cd was the only metal present appreciably (27.16%) in the exchangeable fraction and Cu was the only metal predominantly associated (44.26%) with organic fraction. Zn (45.64%) and Pb (28.26%) were present mainly in the Fe-Mn oxide fraction and the residual fraction was the most dominant solid phase pool of Cr (88.12%) and Ni (70.94%). Assuming that the mobility and bioavailability are related to the solubility of geochemical forms of the metals and decrease in order of extraction, the apparent mobility and potential metal bioavailability for these highly contaminated street dust samples is: Cd>Zn congruent with Pb>Ni>Cu>Cr

Distribution of heavy metals (Pb, Cd, and Zn) in sediment profiles associated to Rhizophora mangle in Sevilla River - Cienaga Grande de Santa Marta, Colombia

International Nuclear Information System (INIS)

Parra, Juan Pablo; Espinosa, Luisa Fernanda

2008-01-01

In order to evaluate the vertical distribution of the heavy metals Pb, Cd, and Zn in sediments associated to Rhizophora mangle plants, potentially bioavailable and not bioavailable concentrations of these metals were determined in three sediment cores collected in the Sevilla River, Cienaga Grande de Santa Marta. Measurements were carried out by inductively coupled plasma-atomic emission spectrometry. The results showed that in Sevilla River mangrove ecosystem these metals are accumulated principally in non-bioavailable forms, this means that a great part or them are retained in the sediment. The retention of Pb, Cd, and Zn in the sediments of this mangrove ecosystem is strongly related to the physicochemical parameters pH, salinity, and redox potential, and to organic matter, and silt and clays contents

SERDP and ESTCP Expert Panel Workshop on Research and Development Needs for Understanding and Assessing the Bioavailability of Contaminants in Soils and Sediments

Science.gov (United States)

2008-11-01

compartments contributing to fish tissue uptake. Develop tools to evaluate contaminant source apportionment into fish and higher trophic levels for use in... apportionment into risk assessments. 7.1.1.2 Improved Understanding of Metal Bioavailability in Sediments. The bioavailability of metals from...Bryan, G.W. and Langston, W.J., 1992. Bioavailability, Accumulation and Effects of Heavy Metals in Sediments with Special Reference to United

The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community

Energy Technology Data Exchange (ETDEWEB)

Wang, Ting [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Urban Transport Emission Control Research Centre, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Hongwen, E-mail: sunhongwen@nankai.edu.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Mao, Hongjun [Urban Transport Emission Control Research Centre, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

2014-08-15

Highlights: • A UV-mutated species, Bacillus subtilis 38, is a good sorbent for multi-metals (Cd, Cr, Hg and Pb). • B38 mixed with NovoGro exhibited a synergetic effect on the immobilization of heavy metals in soil. • DTPA, M3 and BCR were suitable for predicting metal bioavailability for specific classes of plant. • The NovoGro could enhance the proliferation of both exotic B38 and native microbes. • It's a practical strategy for the remediation of actual farmland polluted by multi-heavy metals. - Abstract: Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4–97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals.

The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community

International Nuclear Information System (INIS)

Wang, Ting; Sun, Hongwen; Mao, Hongjun; Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei

2014-01-01

Highlights: • A UV-mutated species, Bacillus subtilis 38, is a good sorbent for multi-metals (Cd, Cr, Hg and Pb). • B38 mixed with NovoGro exhibited a synergetic effect on the immobilization of heavy metals in soil. • DTPA, M3 and BCR were suitable for predicting metal bioavailability for specific classes of plant. • The NovoGro could enhance the proliferation of both exotic B38 and native microbes. • It's a practical strategy for the remediation of actual farmland polluted by multi-heavy metals. - Abstract: Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4–97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals

Efficacy of Designer Biochars with or without Lime Application for Remediating Heavy Metals in Mine Spoil Soils

Science.gov (United States)

Sigua, Gilbert C.; Novak, Jeffrey; Johnson, Mark; Ippolito, James; Spokas, Kurt; Ducey, Thomas; Trippe, Kristin

2017-04-01

A multitude of research investigations have confirmed that biochars can increase soil carbon sequestration, improve critical plant nutrient concentrations, and improve the fertility, chemical, and physical properties of degraded agricultural soils. Recently, biochars ability to sequester metals has caught the attention of the mine reclamation sector. It is proposed that biochar is a suitable amendment to remediate heavy metals in mine spoils, as well as improve chemical conditions for enhanced plant growth. Better plant growth will improve phytostabilization, increase containment of metal-laden sediment, while also reducing potential metal uptake by plants. As such, utilization of a biochar with appropriate chemical and physical characteristics is crucial for effective binding of heavy metals while also improving plant growth conditions in mine spoils. Using two different mine spoils, we conducted laboratory and greenhouse experiments to determine the ability of designer biochar with or without lime application to favorably improve soil pH, reduce heavy metal bioavailability, and improve grass (e.g., wild blue rye) plant nutrient uptake. Preliminary results showed that our designer biochars did increase pH of acid mine spoils significantly (pheavy metals (e.g. aluminum, chromium, zinc, nickel, zinc, manganese, copper and cadmium) in the soils.

Bioavailability of heavy metals in fresh water Tilapia nilotica (Oreachromis niloticus Linnaeus, 1758): potential risk to fishermen and consumers.

Science.gov (United States)

El-Sadaawy, Manal M; El-Said, Ghada F; Sallam, Neama A

2013-01-01

The study was undertaken to assess the accumulation of some heavy metals (Cr, Co, Cu, Ni, Zn, Pb and Cd) in different tissues (muscle, gills, heart, liver, brain, bone and skin) of Tilapia nilotica. It is one of the most edible fish species in Egypt and was collected from a commercial fish farm in order to evaluate their potential risk to fishermen and consumers. This fish farm is fed with discharged water containing agricultural, industrial, sewage and domestic wastes. The length-weight relation and condition factor calculation of Tilapia nilotica samples showed a significant linear regression (r(2) = 0.920) and an average condition factor of 4.1 g/cm(3). This indicated that the health status for the studied fish samples was good. Metal pollution index (MPI) values for the determined heavy metals in the different tissues reflected that the muscle was the only tissue that had the lowest content. Provisional Tolerable Weekly Intake (PTWI) values for the investigated heavy metals were lower than those reported for the permissible limits. The data were evaluated by using ANOVA statistical analysis. For appraising the human health risk effects of heavy metals in fish muscle, estimated dietary intake (EDI) and hazard quotient (HQ) were determined. HQ levels indicated that Cr and Co were the only heavy metals among the determined ones that had values more than unity. Also, their relative contributions in fish consumptions were Cr> Co> Pb> Ni> Cu> Cd> Zn. The highest average HQ value of chromium determined in this study referred to the possible adverse effects of Cr on human health. Accordingly, the potential public health risks from dietary exposure to hazardous contaminants in fish species from fish farms must be continually subjected to research, regulation and debate.

Predicting Metal Speciation & Bioavailability via Estimation of Metal-Organic Thermodynamic Properties

Science.gov (United States)

Prasad, A.; Howells, A. E.; Shock, E.

2017-12-01

The biological fate of any metal depends on its chemical form in the environment. Arsenic for example, is extremely toxic in the form of inorganic As+3 but completely benign in the organic form of arsenobetaine. Thus, given an exhaustive set of reactions and their equilibrium constants (logK), the bioavailability of any metal can be obtained for blood plasma, hydrothermal fluids or any system of interest. While many data exist for metal-inorganic ligands, logK data covering the temperature range of life for metal-organic complexes are sparse. Hence, we decided to estimate metal-organic logK values from correlations with the commonly available values of ligand pKa. Metal ion specific correlations were made with ligands classified according to their electron donor atoms, denticity and other chemical factors. While this approach has been employed before (Carbonaro et al. 2007, GCA 71, 3958-3968), new correlations were developed that provide estimates even when no metal-organic logK is available. In addition, we have used the same methods to make estimates of metal-organic entropy of association (ΔaS), which can provide logK for any temperature of biological relevance. Our current correlations employ logK and ΔaS data from 30 metal ions (like the biologically relevant Fe+3 & Zn+2) and 74 ligands (like formate and ethylenediamine), which can be expanded to estimate the metal-ligand reaction properties for these 30 metal ions with a possibly limitless number of ligands that may belong to our categories of ligands. With the help of such data, copper speciation was obtained for a defined growth medium for methanotrophs employed by Morton et al. (2000, AEM 66, 1730-1733) that agrees with experimental measurements showing that the free metal ion may not be the bioavailable form in all conditions. These results encourage us to keep filling the gaps in metal-organic logK data and continue finding relationships between biological responses (like metal-accumulation ratios

Removal of heavy metals from polluted soil using the citric acid fermentation broth: a promising washing agent.

Science.gov (United States)

Zhang, Hongjiao; Gao, Yuntao; Xiong, Huabin

2017-04-01

The citric acid fermentation broth was prepared and it was employed to washing remediation of heavy metal-polluted soil. A well-defined washing effect was obtained, the removal percentages using citric acid fermentation broth are that 48.2% for Pb, 30.6% for Cu, 43.7% for Cr, and 58.4% for Cd and higher than that using citric acid solution. The kinetics of heavy metals desorption can be described by the double constant equation and Elovich equation and is a heterogeneous diffusion process. The speciation analysis shows that the citric acid fermentation broth can effectively reduce bioavailability and environmental risk of heavy metals. Spectroscopy characteristics analysis suggests that the washing method has only a small effect on the mineral composition and does not destroy the framework of soil system. Therefore, the citric acid fermentation broth is a promising washing agent and possesses a potential practical application value in the field of remediation of soils with a good washing performance.

Biogenic precipitation of manganese oxides and enrichment of heavy metals at acidic soil pH

Science.gov (United States)

Mayanna, Sathish; Peacock, Caroline L.; Schäffner, Franziska; Grawunder, Anja; Merten, Dirk; Kothe, Erika; Büchel, Georg

2014-05-01

The precipitation of biogenic Mn oxides at acidic pH is rarely reported and poorly understood, compared to biogenic Mn oxide precipitation at near neutral conditions. Here we identified and investigated the precipitation of biogenic Mn oxides in acidic soil, and studied their role in the retention of heavy metals, at the former uranium mining site of Ronneburg, Germany. The site is characterized by acidic pH, low carbon content and high heavy metal loads including rare earth elements. Specifically, the Mn oxides were present in layers identified by detailed soil profiling and within these layers pH varied from 4.7 to 5.1, Eh varied from 640 to 660 mV and there were enriched total metal contents for Ba, Ni, Co, Cd and Zn in addition to high Mn levels. Using electron microprobe analysis, synchrotron X-ray diffraction and X-ray absorption spectroscopy, we identified poorly crystalline birnessite (δ-MnO2) as the dominant Mn oxide in the Mn layers, present as coatings covering and cementing quartz grains. With geochemical modelling we found that the environmental conditions at the site were not favourable for chemical oxidation of Mn(II), and thus we performed 16S rDNA sequencing to isolate the bacterial strains present in the Mn layers. Bacterial phyla present in the Mn layers belonged to Firmicutes, Actinobacteria and Proteobacteria, and from these phyla we isolated six strains of Mn(II) oxidizing bacteria and confirmed their ability to oxidise Mn(II) in the laboratory. The biogenic Mn oxide layers act as a sink for metals and the bioavailability of these metals was much lower in the Mn layers than in adjacent layers, reflecting their preferential sorption to the biogenic Mn oxide. In this presentation we will report our findings, concluding that the formation of natural biogenic poorly crystalline birnessite can occur at acidic pH, resulting in the formation of a biogeochemical barrier which, in turn, can control the mobility and bioavailability of heavy metals in

In situ stabilization of heavy metals in multiple-metal contaminated paddy soil using different steel slag-based silicon fertilizer.

Science.gov (United States)

Ning, Dongfeng; Liang, Yongchao; Song, Alin; Duan, Aiwang; Liu, Zhandong

2016-12-01

Steel slag has been widely used as amendment and silicon fertilizer to alleviate the mobility and bioavailability of heavy metals in soil. The objective of this study was to evaluate the influence of particle size, composition, and application rate of slag on metal immobilization in acidic soil, metals uptake by rice and rice growth. The results indicated that application of slag increased soil pH, plant-available silicon concentrations in soil, and decreased the bioavailability of metals compared with control treatment, whereas pulverous slag (S1) was more effective than granular slag (S2 and S3). The acid-extractable fraction of Cd in the spiked soil was significantly decreased with application of S1 at rates of 1 and 3 %, acid-extractable fractions of Cu and Zn were decreased when treated at 3 %. Use of S1 at both rates resulted in significantly lower Cd, Cu, and Zn concentrations in rice tissues than in controls by 82.6-92.9, 88.4-95.6, and 67.4-81.4 %, respectively. However, use of pulverous slag at 1 % significantly promotes rice growth, restricted rice growth when treated at 3 %. Thus, the results explained that reduced particle size and suitable application rate of slag could be beneficial to rice growth and metals stabilization.

Heavy metal sorption by microalgae

International Nuclear Information System (INIS)

Sandau, E.; Sandau, P.; Pulz, O.

1996-01-01

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

Bioavailability and bioaccumulation of metal-based engineered nanomaterials in aquatic environments: concepts and processes: chapter 5

Science.gov (United States)

Luoma, Samuel N.; Khan, Farhan R.; Croteau, Marie-Noële

2014-01-01

Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.

Dynamic speciation analysis and bioavailability of metals in aquatic systems

NARCIS (Netherlands)

Leeuwen, van H.P.; Town, R.M.; Buffle, J.; Cleven, R.F.M.J.; Davison, W.; Puy, J.; Riemsdijk, van W.H.; Sigg, L.

2005-01-01

Dynamic metal speciation analysis in aquatic ecosystems is emerging as a powerful basis for development of predictions of bioavailability and reliable risk assessment strategies. A given speciation sensor is characterized by an effective time scale or kinetic window that defines the measurable metal

Soil Heavy Metal Concentrations in Green Space of Mobarake Steel Complex

Directory of Open Access Journals (Sweden)

vahid Moradinasab

2017-01-01

Full Text Available Introduction: Water shortage in arid and semiarid regions of the world is a cause of serious concerns. The severe water scarcity urges the reuse of treated wastewater effluent and marginal water as a resource for irrigation. Mobarake Steel Complex has been using treated industrial wastewater for drip-irrigation of trees in about 1350 ha of its green space. However, wastewater may contain some amounts of toxic heavy metals, which create problems. Excessive accumulation of heavy metals in agricultural soils through wastewater irrigation may not only result in soil contamination, but also affect food quality and safety. Improper irrigation management, however, can lead to the loss of soil quality through such processes as contamination and salination. Soil quality implies its capacity to sustain biological productivity, maintain environmental quality, and enhance plants, human and animal health. Soil quality assessment is a tool that helps managers to evaluate short-term soil problems and appropriate management strategies for maintaining soil quality in the long time. Mobarakeh Steel Complex has been using treated wastewater for irrigation of green space to combat water shortage and prevent environmental pollution. This study was performed to assess the impact of short- middle, and long-term wastewater irrigation on soil heavy metal concentration in green space of Mobarake Steel complex. Materials and Methods: The impacts of wastewater irrigation on bioavailable and total heavy metal concentrations in the soils irrigated with treated wastewater for 2, 6 and 18 years as compared to those in soils irrigated with groundwater and un-irrigated soils. Soils were sampled from the wet bulb produced by under-tree sprinklers in three depths (0-20, 20-40 and 40-60 cm. Soil samples were air-dried, and crushed to pass through a 2-mm sieve. Plant-available metal concentrations were extracted from the soil with diethylenetriaminepentaacetic acid-CaCl2

Experiences of the Use of Bio monitors for Heavy Metal Pollution Control in Almendares River

International Nuclear Information System (INIS)

Olivares- Rieumont, S.; Lima, L.; De la Rosa, D.; Martinez, F.; Borroto, J.; Columbie, I.; Sanchez, M.J.

2003-01-01

Full Text: This work is the first approach to establish a monitoring system for heavy metals in the Almendares Vento Basin. This basin is the most important watershed of Havana City, which main river is the Almendares River, that with 42 km of length goes through 5 municipalities, where live more than 500,000 inhabitants. The river receives a large pollution loads from more than 50 pollution sources of Havana City. Inputs of toxic substances like heavy metals come from the industries located along the river and tributaries, the urban discharges and from important speedways in both shores of the river. In the work, concentrations of Cd, Pb, Zn, Cu, Ni, Co and Cr in sediments, water, gastropod species Tarebia granifera Lamarck, macrophyte Eichhornia Crassipes and fish from the specie Gambusia were evaluated at 14 stations during the dry season of 2003. Concentrations of copper and lead in water samples exceeded applicable guidelines for many of the sites monitored in the river basin. Heavy metals in sediments were analysed using three-stage sequential extraction procedure. In sediments high contents of studied metals were found in the bioavailable fraction. Some stations were highly polluted with all elements. Two main sources of pollution with heavy metals could be identified in the basin due to the higher concentration of most of the studied metals in the analized sampling stations. Pb concentrations were high in almost all the stations. Similar behaviour was found for the metal concentration in Eichhornia Crassipes roots, that appear to have an interesting potential as bio monitor of the pollution with heavy metals. Tarebia granifera Lamarck only could be found in 5 of the 14 stations monitored, and it presence is related with the quality of the river water. The magnitude of contamination was estimated by the comparison between local backgrounds and concentration of metals measured. Only high concentration of Zn were found in the Gambusia tissue, and no

Lethal concentrations of heavy metals in tissue of earthworms. Interim report No. 1, June-July 1987

Energy Technology Data Exchange (ETDEWEB)

Bouche, M.B.; Brun, P.; Gal, J.Y.; Reza, A.

1987-07-01

The objective of this phase of Toxicological Research on Lethal Concentrations of Heavy Metals in Tissue of Earthworms is to improve both ecotoxicological tests in a chemically defined medium and a procedure of bioavailability study in field. In this first period the authors worked on breeding stock of earthworms (species Eisenia fetida andrei) in decomposing manure heaps to increase them and make them grow. They also installed two chambers with thermostats fixed at 20 C to do toxicity tests and chose chemical species of heavy-metal contaminants. For field procedure, they improved a practical way to sample both earthworms and soil in very close connections, avoiding artifacts. For both field procedure and laboratory tests, they tried to standardize a method to dissolve earthworms in acids and to analyze the concentrations of heavy metals inside. A preliminary set of samples in calcareous soils was started and analysis of them are in progress. For lab tests, the first part of the test (preliminary test) was started with the different contaminants (cadmium, copper, arsenic, mercury) in an artificial medium named Artisol.

The effectiveness of spent coffee grounds and its biochar on the amelioration of heavy metals-contaminated water and soil using chemical and biological assessments.

Science.gov (United States)

Kim, Min-Suk; Min, Hyun-Gi; Koo, Namin; Park, Jeongsik; Lee, Sang-Hwan; Bak, Gwan-In; Kim, Jeong-Gyu

2014-12-15

Spent coffee grounds (SCG) and charred spent coffee grounds (SCG-char) have been widely used to adsorb or to amend heavy metals that contaminate water or soil and their success is usually assessed by chemical analysis. In this work, the effects of SCG and SCG-char on metal-contaminated water and soil were evaluated using chemical and biological assessments; a phytotoxicity test using bok choy (Brassica campestris L. ssp. chinensis Jusl.) was conducted for the biological assessment. When SCG and SCG-char were applied to acid mine drainage, the heavy metal concentrations were decreased and the pH was increased. However, for SCG, the phytotoxicity increased because a massive amount of dissolved organic carbon was released from SCG. In contrast, SCG-char did not exhibit this phenomenon because any easily released organic matter was removed during pyrolysis. While the bioavailable heavy metal content decreased in soils treated with SCG or SCG-char, the phytotoxicity only rose after SCG treatment. According to our statistical methodology, bioavailable Pb, Cu and As, as well as the electrical conductivity representing an increase in organic content, affected the phytotoxicity of soil. Therefore, applying SCG during environment remediation requires careful biological assessments and evaluations of the efficiency of this remediation technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relating environmental availability to bioavailability: soil-type-dependent metal accumulation in the oligochaete Eisenia andrei.

Science.gov (United States)

Peijnenburg, W J; Baerselman, R; de Groot, A C; Jager, T; Posthuma, L; Van Veen, R P

1999-11-01

Body residues are often better estimates of the amount of a chemical at the sites of toxic action in an organism than ambient soil concentrations, because bioavailability differences among soils are explicitly taken into account in considerations of body residues. Often, however, insufficient attention is paid to the rate and extent at which tissue concentrations respond to soil concentrations and soil characteristics. In this contribution the impact of soil characteristics on the environmental bioavailability of heavy metals for the oligochaete worm Eisenia andrei is reported. Uptake of As, Cd, Cr, Cu, Ni, Pb, and Zn in 20 Dutch field soils and in OECD artificial soil was quantified as a function of time. Internal metal concentrations varied less than the corresponding external levels. Metal uptake and elimination were both metal- and species-dependent. Worms typically attained steady-state concentrations rapidly for Cr, Cu, Ni, and Zn. Internal concentrations similar to those in the cultivation medium, linearly increasing body concentrations, or steady-state internal concentrations well above those in the cultivation medium were found for As, Cd, and Pb. Multivariate expressions were derived to describe uptake rate constants, steady-state concentrations, and bioaccumulation factors as a function of soil characteristics. Soil acidity is the most important solid-phase characteristic modulating the availability of As, Cd, and Pb. Although additional semimechanistic calculations yielded evidence of pore-water-related uptake of Cd and Pb modulated by competition between H(+) and metal ions at the active sites of the membranes, the findings for Cr, Cu, Ni, and Zn point to additional influences, among which is probably regulation. Copyright 1999 Academic Press.

Heavy metal uptake of Geosiphon pyriforme

Energy Technology Data Exchange (ETDEWEB)

Scheloske, Stefan E-mail: stefan.scheloske@mpi-hd.mpg.de; Maetz, Mischa; Schuessler, Arthur

2001-07-01

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

Biomolecules for Removal of Heavy Metal.

Science.gov (United States)

Singh, Namita Ashish

2017-01-01

Patents reveal that heavy metals are natural constituents of the earth's crust, but some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to other synthetic biosorbents due to their environmental friendly nature and cost effectiveness. The goal of this work is to identify the role of biomolecules like polysaccharides, polypeptides, natural compounds containing aromatic acid etc. for heavy metal removal by bio sorption. It has been observed that efficiency of biomolecules can be increased by functionalization e.g. cellulose functionalization with EDTA, chitosan with sulphur groups, alginate with carboxyl/ hydroxyl group etc. It was found that the porous structure of aerogel beads improves both sorption and kinetic properties of the material. Out of polypeptides metallothionein has been widely used for removal of heavy metal up to 88% from seawater after a single centrifugation. These cost effective functionalized biomolecules are significantly used for remediation of heavy metals by immobilizing these biomolecules onto materials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Divergent biology of facultative heavy metal plants.

Science.gov (United States)

Bothe, Hermann; Słomka, Aneta

2017-12-01

Among heavy metal plants (the metallophytes), facultative species can live both in soils contaminated by an excess of heavy metals and in non-affected sites. In contrast, obligate metallophytes are restricted to polluted areas. Metallophytes offer a fascinating biology, due to the fact that species have developed different strategies to cope with the adverse conditions of heavy metal soils. The literature distinguishes between hyperaccumulating, accumulating, tolerant and excluding metallophytes, but the borderline between these categories is blurred. Due to the fact that heavy metal soils are dry, nutrient limited and are not uniform but have a patchy distribution in many instances, drought-tolerant or low nutrient demanding species are often regarded as metallophytes in the literature. In only a few cases, the concentrations of heavy metals in soils are so toxic that only a few specifically adapted plants, the genuine metallophytes, can cope with these adverse soil conditions. Current molecular biological studies focus on the genetically amenable and hyperaccumulating Arabidopsis halleri and Noccaea (Thlaspi) caerulescens of the Brassicaceae. Armeria maritima ssp. halleri utilizes glands for the excretion of heavy metals and is, therefore, a heavy metal excluder. The two endemic zinc violets of Western Europe, Viola lutea ssp. calaminaria of the Aachen-Liège area and Viola lutea ssp. westfalica of the Pb-Cu-ditch of Blankenrode, Eastern Westphalia, as well as Viola tricolor ecotypes of Eastern Europe, keep their cells free of excess heavy metals by arbuscular mycorrhizal fungi which bind heavy metals. The Caryophyllaceae, Silene vulgaris f. humilis and Minuartia verna, apparently discard leaves when overloaded with heavy metals. All Central European metallophytes have close relatives that grow in areas outside of heavy metal soils, mainly in the Alps, and have, therefore, been considered as relicts of the glacial epoch in the past. However, the current

Heavy metals concentrations and risk assessment of roselle and jute mallow cultivated with three compost types

Directory of Open Access Journals (Sweden)

M. Abubakari

2017-12-01

Full Text Available Field experiments were conducted at the research field of the CSIR–SARI near Nyankpala in the Northern region of Ghana during the major growing seasons of 2014 and 2015. The objectives of the study were to determine the effect of three compost types i.e. Accra compost and recycling plant (ACARP compost; decentralised compost (DeCo and composted deep litter chicken manure (CDLCM on heavy metals concentrations in roselle (Hibiscus sabdariffa L. and jute mallow (Corchorus olitorius L. and the health risk of these vegetables to adults and children. The composts were each applied at the rate of 10 t/ha in a randomized complete block design in four replications. The concentrations of Cd and Pb in the leaves of roselle were 0.8 mg/kg and 5.0 mg/kg whiles in jute mallow, they were 0.7 mg/kg and 6.0 mg/kg, respectively. These concentrations were above the Maximum residue levels (MRLs of 0.2 mg/kg for Cd and 0.3 mg/kg for Pb in the standards of the European Commission and Codex Alimentarius Commission. The low soil pH might have facilitated the bioavailability of the heavy metals resulting in concentrations that could be harmful to consumers of these vegetables. There is, therefore, the need to amend the soil pH of the study area. An upward adjustment of the pH of the composts used can also help in reducing the bioavailability of heavy metals to roselle and jute mallow cultivated in soils with low pH.

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.

Process for removing heavy metal compounds from heavy crude oil

Science.gov (United States)

Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

1991-01-01

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

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)

Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

International Nuclear Information System (INIS)

Pauget, B.; Gimbert, F.; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

2012-01-01

Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO 4 , EDTA, CaCl 2 , NH 4 NO 3 , NaNO 3 , free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r² adj = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r² adj = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: ► New approach to identify chemical methods able to predict metal bioavailability to snails. ► Bioavailability of cadmium, lead and zinc to snails was determined by

Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

Energy Technology Data Exchange (ETDEWEB)

Pauget, B.; Gimbert, F., E-mail: frederic.gimbert@univ-fcomte.fr; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

2012-08-01

Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO{sub 4}, EDTA, CaCl{sub 2}, NH{sub 4}NO{sub 3}, NaNO{sub 3}, free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r Superscript-Two {sub adj} = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r Superscript-Two {sub adj} = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: Black-Right-Pointing-Pointer New approach to identify chemical methods able to predict metal bioavailability

(17) ACCUMULATION OF HEAVY METAL

African Journals Online (AJOL)

Adeyinka Odunsi

Spectrophotometer (AAS) 2ID using their respective lamp and wavelengths. Calculation ... (Table 2). Concentration of heavy metals in the cassava. Lead and chromium were not significantly ..... Market basket survey for some heavy metals in ...

Poisoning of domestic animals with heavy metals

Directory of Open Access Journals (Sweden)

Velev Romel

2009-01-01

Full Text Available The term heavy metal refers to a metal that has a relatively high density and is toxic for animal and human organism at low concentrations. Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed. To a small extent they enter animal organism via food, drinking water and air. Some heavy metals (e.g cooper, iron, chromium, zinc are essential in very low concentrations for the survival of all forms of life. These are described as essential trace elements. However, when they are present in greater quantities, like the heavy metals lead, cadmium and mercury which are already toxic in very low concentrations, they can cause metabolic anomalies or poisoning. Heavy metal poisoning of domestic animals could result, for instance, from drinking-water contamination, high ambient air concentrations near emission sources, or intake via the food chain. Heavy metals are dangerous because they tend to bioaccumulate in a biological organism over time. Manifestation of toxicity of individual heavy metals varies considerably, depending on dose and time of exposure, species, gender and environmental and nutritional factors. Large differences exist between the effects of a single exposure to a high concentration, and chronic exposures to lower doses. The aim of this work is to present the source of poisoning and toxicity of some heavy metals (lead, mercury, cadmium, thallium, arsenic, as well as new data about effects of those heavy metals on the health of domestic animals. .

Evaluation of soil metal bioavailability estimates using two plant species (L. perenne and T. aestivum) grown in a range of agricultural soils treated with biosolids and metal salts

International Nuclear Information System (INIS)

Black, Amanda; McLaren, Ronald G.; Reichman, Suzanne M.; Speir, Thomas W.; Condron, Leo M.

2011-01-01

Few studies have quantified the accuracy of soil metal bioavailability assays using large datasets. A meta-analysis from experiments spanning 6 months to 13 years on 12 soil types, compared bioavailability estimate efficiencies for wheat and ryegrass. Treatments included biosolids ± metals, comparing total metal, Ca(NO 3 ) 2 , EDTA, soil solution, DGT and free ion activity. The best correlations between soil metal bioavailability and shoot concentrations were for Ni using Ca(NO 3 ) 2 (r 2 = 0.72) which also provided the best estimate of Zn bioavailability (r 2 = 0.64). DGT provided the best estimate of Cd bioavailability, accounting for 49% of shoot Cd concentrations. There was no reliable descriptor of Cu bioavailability, with less than 35% of shoot Cu concentrations defined. Thus interpretation of data obtained from many soil metal bioavailability assays is unreliable and probably flawed, and there is little justification to look beyond Ca(NO 3 ) 2 for Ni and Zn, and DGT for Cd. - Highlights: → A meta-analysis evaluated the efficacy of soil metal bioavailability assays. → DGT could explain 49% of shoot Cd concentration. → There is little justification to look beyond Ca(NO 3 ) 2 for Ni and Zn. - A meta-analysis of soil metal bioavailability estimates for 12 soil types concluded that there is little justification to look beyond Ca(NO 3 ) 2 for Ni and Zn, and DGT for Cd.

A plasmid containing the human metallothionein II gene can function as an antibody-assisted electrophoretic biosensor for heavy metals.

Science.gov (United States)

Wooten, Dennis C; Starr, Clarise R; Lyon, Wanda J

2016-01-01

Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with biochemical systems can be laborious and unreliable. To generate a reliable easy-to-use biologically-based biosensor system, the entire human metallothionein-II (MT-II) gene was incorporated into a plasmid (pUC57-MT) easily replicated in Escherichia coli. In this system, a commercial polyclonal antibody raised against human metal-responsive transcription factor-1 protein (MTF-1 protein) could modify the electrophoretic migration patterns (i.e. cause specific decreases in agarose gel electrophoretic mobility) of the plasmid in the presence or absence of heavy metals other than zinc (Zn). In the study here, heavy metals, MTF-1 protein, and polyclonal anti-MTF-1 antibody were used to assess pUC57-MT plasmid antibody-assisted electrophoretic mobility. Anti-MTF-1 antibody bound both MTF-1 protein and pUC57-MT plasmid in a non-competitive fashion such that it could be used to differentiate specific heavy metal binding. The results showed that antibody-inhibited plasmid migration was heavy metal level-dependent. Zinc caused a unique mobility shift pattern opposite to that of other metals tested, i.e. Zn blocked the antibody ability to inhibit plasmid migration, despite a greatly increased affinity for DNA by the antibody when Zn was present. The Zn effect was reversed/modified by adding MTF-1 protein. Additionally, antibody inhibition of plasmid mobility was resistant to heat pre-treatment and trypsinization, indicating absence of residual DNA extraction-resistant bacterial DNA binding proteins. DNA binding by anti-DNA antibodies may be commonly enhanced by xenobiotic heavy metals and elevated levels of Zn, thus making them potentially effective tools for assessment of heavy metal bioavailability in aqueous solutions and

Oil Spill Related Heavy Metal: A Review

International Nuclear Information System (INIS)

Ahmad Dasuki Mustafa; Hafizan Juahir; Kamaruzzaman Yunus; Mohammad Azizi Amran; Che Noraini Che Hasnam; Fazureen Azaman; Ismail Zainal Abidin; Syahril Hirman Azmee; Nur Hishaam Sulaiman

2015-01-01

Oil spill occurs every day worldwide and oil contamination is a significant contributor for the higher levels of heavy metals in the environment. This study is purposely to summarize the heavy metals which significant to major oil spill incidents around the world and effects of toxic metals to human health. The study performed a comprehensive review of relevant scientific journal articles and government documents concerning heavy metals contamination and oil spills. Overall, the heavy metals most frequently been detected in oil spill related study where Pb>Ni>V>Zn>Cd and caused many effects to human health especially cancer. In conclusion, the comparison of heavy metal level between the post - spill and baseline levels must be done, and implementation of continuous monitoring of heavy metal. In addition, the result based on the strategies must be transparent to public in order to maintaining human health. (author)

Potential bioavailability assessment, source apportionment and ecological risk of heavy metals in the sediment of Brisbane River estuary, Australia.

Science.gov (United States)

Duodu, Godfred Odame; Goonetilleke, Ashantha; Ayoko, Godwin A

2017-04-15

A weak acid extraction was used to mobilize the loosely bound metals in estuary sediment samples. More than 30% of Ag, As, Ca, Cd, Co, Cu, Hg, Mn Ni, Pb and Zn were leached from the sediment showing that these metals are significantly present in the bioavailable form. PCA/APCS identified three sources of the metals, namely: lithogenic accounting for 72%, shipping related contributing 15% and traffic related representing 13% of the total load. Application of pollution index (PI) and modified pollution index (MPI) revealed that the sediment range from unpolluted to heavily polluted while ecological risk index (RI) classifies the sediment as posing low ecological risk modified ecological risk index (MRI) suggests considerable to very high ecological risk. To provide holistic insights into the ecological risks posed by metals, enrichment factor, MPI and MRI are recommended for the assessment of sediment in complex environments such as estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recovering heavy rare earth metals from magnet scrap

Science.gov (United States)

Ott, Ryan T.; McCallum, Ralph W.; Jones, Lawrence L.

2017-08-08

A method of treating rare earth metal-bearing permanent magnet scrap, waste or other material in a manner to recover the heavy rare earth metal content separately from the light rare earth metal content. The heavy rare earth metal content can be recovered either as a heavy rare earth metal-enriched iron based alloy or as a heavy rare earth metal based alloy.

Evaluation of calcium di-sodium EDTA intramuscular injection using gamma scintigraphy against heavy metal poisoning

International Nuclear Information System (INIS)

Kumar, N.; Soni, S.; Mehra, L.; Mittal, G.; Nishad, D.K.; Bhatnagar, A.; Singh, T.; Ahmad, F.J.

2010-01-01

Full text: Heavy metals become toxic when they are not metabolized by the body and accumulate in soft tissues. These metals may enter the body through food, water, air or absorption through skin when an individual is exposed to areas with high heavy metal content such as agriculture, pharmaceutical manufacturing, paint and heavy metal industries or residential settings. Majority of population commonly get affected by heavy metal poisoning. Heavy metal poisoning is more likely to result through inhalation or ingestion route. Aim of the present study is to provide an easy, effective and controlled chelating therapy against heavy metal using Ca-disodium EDTA intramuscular injection. Ca-disodium-EDTA and Sesame oil were procured from Merck, India and Sigma Aldrich, USA respectively. Ca-Na 2 EDTA radiolabeling with 99m Tc-pertechnetate was standardized using stannous ions as reducing agent. The hypothesis of present work is to maintain effective concentration of chelating agent in blood for prolong time period. To test this hypothesis, we studied 1% Ca-Na 2 EDTA blood bioavailability after intramuscular depot administration in new zealand white rabbit. The optimized radiolabeled intramuscular formulation was evaluated for its dissolution and permeation studies in isotonic buffer solution were envisaged through radiometry. Sub-acute toxicity studies were performed after a single dose intramuscular administration of 1% Ca-Na 2 EDTA in Sprague Dawley rats. Radiolabeled Ca-disodium-EDTA (>95% labeled) was found to be fairly stable up to 24 h in physiological solution (Serum) as well as in normal saline with negligible degradation of 2.5% and 5.0% respectively, thereby indicating high stability of radiolabeled product. In-vitro data indicates that control release pattern (Cmax 24 hrs) with effective concentration up to seven days. 99m Tc-CaNa 2 EDTA retention at depot site was estimated up to 3 days by scintigraphy. Subacute toxicity studies done by histopathological

Factors Affecting the Binding of a Recombinant Heavy Metal-Binding Domain (CXXC motif Protein to Heavy Metals

Directory of Open Access Journals (Sweden)

Kamala Boonyodying

2012-06-01

Full Text Available A number of heavy metal-binding proteins have been used to study bioremediation. CXXC motif, a metal binding domain containing Cys-X-X-Cys motif, has been identified in various organisms. These proteins are capable of binding various types of heavy metals. In this study, heavy metal binding domain (CXXC motif recombinant protein encoded from mcsA gene of S. aureus were cloned and overexpressed in Escherichia coli. The factors involved in the metal-binding activity were determined in order to analyze the potential of recombinant protein for bioremediation. A recombinant protein can be bound to Cd2+, Co2+, Cu2+ and Zn2+. The thermal stability of a recombinant protein was tested, and the results showed that the metal binding activity to Cu2+ and Zn2+ still exist after treating the protein at 85ºC for 30 min. The temperature and pH that affected the metal binding activity was tested and the results showed that recombinant protein was still bound to Cu2+ at 65ºC, whereas a pH of 3-7 did not affect the metal binding E. coli harboring a pRset with a heavy metal-binding domain CXXC motif increased the resistance of heavy metals against CuCl2 and CdCl2. This study shows that metal binding domain (CXXC motif recombinant protein can be effectively bound to various types of heavy metals and may be used as a potential tool for studying bioremediation.

Evaluation of soil metal bioavailability estimates using two plant species (L. perenne and T. aestivum) grown in a range of agricultural soils treated with biosolids and metal salts

Energy Technology Data Exchange (ETDEWEB)

Black, Amanda, E-mail: amanda.black@lincoln.ac.nz [Department of Soil and Physical Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln 7647, Christchurch (New Zealand); McLaren, Ronald G. [Department of Soil and Physical Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln 7647, Christchurch (New Zealand); Reichman, Suzanne M. [School of Civil, Environmental and Chemical Engineering, RMIT University, GPO Box 2476, Melbourne 3001 (Australia); Speir, Thomas W. [Institute of Environmental Science and Research Ltd (ESR), PO Box 50348, Porirua 5240 (New Zealand); Condron, Leo M. [Department of Soil and Physical Sciences, Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln 7647, Christchurch (New Zealand)

2011-06-15

Few studies have quantified the accuracy of soil metal bioavailability assays using large datasets. A meta-analysis from experiments spanning 6 months to 13 years on 12 soil types, compared bioavailability estimate efficiencies for wheat and ryegrass. Treatments included biosolids {+-} metals, comparing total metal, Ca(NO{sub 3}){sub 2}, EDTA, soil solution, DGT and free ion activity. The best correlations between soil metal bioavailability and shoot concentrations were for Ni using Ca(NO{sub 3}){sub 2} (r{sup 2} = 0.72) which also provided the best estimate of Zn bioavailability (r{sup 2} = 0.64). DGT provided the best estimate of Cd bioavailability, accounting for 49% of shoot Cd concentrations. There was no reliable descriptor of Cu bioavailability, with less than 35% of shoot Cu concentrations defined. Thus interpretation of data obtained from many soil metal bioavailability assays is unreliable and probably flawed, and there is little justification to look beyond Ca(NO{sub 3}){sub 2} for Ni and Zn, and DGT for Cd. - Highlights: > A meta-analysis evaluated the efficacy of soil metal bioavailability assays. > DGT could explain 49% of shoot Cd concentration. > There is little justification to look beyond Ca(NO{sub 3}){sub 2} for Ni and Zn. - A meta-analysis of soil metal bioavailability estimates for 12 soil types concluded that there is little justification to look beyond Ca(NO{sub 3}){sub 2} for Ni and Zn, and DGT for Cd.

Heavy metals precipitation in sewage sludge

NARCIS (Netherlands)

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

2005-01-01

There is a great need for heavy metal removal from strongly metal-polluted sewage sludges. One of the advantages of heavy metal removal from this type of sludge is the possibility of the sludge disposal to landfill with reduced risk of metals being leached to the surface and groundwater. Another

[Research advances in heavy metals pollution ecology of diatom].

Science.gov (United States)

Ding, Teng-Da; Ni, Wan-Min; Zhang, Jian-Ying

2012-03-01

Diatom, due to its high sensitivity to environmental change, is one of the bio-indicators of aquatic ecosystem health, and some typical diatom species have been applied to indicate the heavy metals pollution of water body. With the focus on the surface water heavy metals pollution, this paper reviewed the research advances in the toxic effect of heavy metals pollution on diatom, biosorption and bioaccumulation of heavy metals by diatom, ecological adaptation mechanisms of diatom to heavy metals pollution, and roles of diatom as bio-indicator and in ecological restoration of heavy metals pollution. The growth tendency of diatom and the morphological change of frustule under heavy metals pollution as well as the differences in heavy metals biosorption and bioaccumulation by diatom, the ecological adaptation mechanisms of diatom on heavy metals surface complexation and ion exchange, and the roles of diatom as bio-indicator and in ecological restoration of heavy metals polluted water body were also discussed. This review could provide scientific evidences for the prevention of aquatic ecosystems heavy metals pollution and related early warning techniques.

Bioavailability

Energy Technology Data Exchange (ETDEWEB)

Jensen, J. [National Environmental Research Inst., Silkeborg (Denmark). Dept. of Terrestrial Ecology

2003-07-01

Although commonly discussed and debated the scientific basis for adequately using bioavailability in ecological risk assessment is still relatively weak. One of the first obstacles to solve is to define the term properly. It must be recognised that bioavailability is dynamic processes comprising several distinct phases. One is the adsorption/desorption process (chemical availability) controlled by parameters like pH, clay, CEC and organic matter. Another one is a physiological driven uptake process (biological availability) controlled by species-specific parameters like anatomy, feeding strategy, preferences in micro-habitat etc. The last one is an internal allocation process (toxicological availability) controlled by species specific parameters like metabolism, detoxification, storage, excretion, energy resources etc. The complexity of bioavailability means that there seems no straight way forward how to handle bioavailability in the risk assessment procedure. Nevertheless, what almost all people - from scientists to problem holders and responsible authorities - agree upon is that there is a need for alternatives to the common use of the 'total concentration approach'. From an ecological perspective, biological tools would be preferred when assessing risk to ecosystems. However, due to the lower cost and higher reproducibility chemical tools may often be the best suitable solutions. The outcome of mild extraction procedures like CaCl{sub 2} have for example been shown to correlated relatively well to ecotoxicological effects of heavy metals. Bioavailability of organic pollutants has less frequently been correlated to ecological effects of organisms within the soil compartment and adjacent water systems. It has nevertheless been documented that mild extractors like n-butanol, propanol, ethyl acetate and acetonitrile are useful in predicting the uptake of PAHs in earthworms and plants as well as microbial toxicity. (orig.)

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.

Impacts of landscape remediation on the heavy metal pollution dynamics of a lake surrounded by non-ferrous smelter waste

Energy Technology Data Exchange (ETDEWEB)

Blake, William H. [Department of Geography, University of Wales, Swansea SA2 8PP (United Kingdom)]. E-mail: william.blake@plymouth.ac.uk; Walsh, Rory P.D. [Department of Geography, University of Wales, Swansea SA2 8PP (United Kingdom); Reed, Jane M. [Department of Geography, University of Hull, Cottingham Road, Hull HU6 7RX (United Kingdom); Barnsley, Michael J. [Department of Geography, University of Wales, Swansea SA2 8PP (United Kingdom); Smith, Jamie [Department of Geography, University of Wales, Swansea SA2 8PP (United Kingdom)

2007-07-15

Heavy metal concentrations and potential bioavailability are reported for sediment in a shallow flood detention lake surrounded by reclaimed, smelter-contaminated land. A range of sediment column proxy indicators is used to explore changes in pollution dynamics with remediation. Sediment concentrations of Pb and Zn are high at {approx}600 and 20 000 mg kg{sup -1}, respectively. Less than 7% of total Pb is potentially bioavailable following sequential extraction as opposed to 47% of Zn. Metal transfer mechanisms to lake sediment include detrital inputs, scavenging by particulates and biogeochemical precipitation. Sedimentary evidence indicates that detrital inputs to the lake declined following land reclamation after which it is proposed that dissolved inputs increased with leaching of reworked waste material. Whilst downcore metal profiles may be subject to post-depositional change, diatom analysis suggests more recent improvements in water quality. The potential for post-remediation pollution episodes relating to metal release from historic sedimentary stores should be considered in future remediation strategies. - The contaminant hydrology of reworked smelter spoil is complex.

Impacts of landscape remediation on the heavy metal pollution dynamics of a lake surrounded by non-ferrous smelter waste

International Nuclear Information System (INIS)

Blake, William H.; Walsh, Rory P.D.; Reed, Jane M.; Barnsley, Michael J.; Smith, Jamie

2007-01-01

Heavy metal concentrations and potential bioavailability are reported for sediment in a shallow flood detention lake surrounded by reclaimed, smelter-contaminated land. A range of sediment column proxy indicators is used to explore changes in pollution dynamics with remediation. Sediment concentrations of Pb and Zn are high at ∼600 and 20 000 mg kg -1 , respectively. Less than 7% of total Pb is potentially bioavailable following sequential extraction as opposed to 47% of Zn. Metal transfer mechanisms to lake sediment include detrital inputs, scavenging by particulates and biogeochemical precipitation. Sedimentary evidence indicates that detrital inputs to the lake declined following land reclamation after which it is proposed that dissolved inputs increased with leaching of reworked waste material. Whilst downcore metal profiles may be subject to post-depositional change, diatom analysis suggests more recent improvements in water quality. The potential for post-remediation pollution episodes relating to metal release from historic sedimentary stores should be considered in future remediation strategies. - The contaminant hydrology of reworked smelter spoil is complex

Effects of past sewage sludge additions on heavy metal availability in light textured soils: implications for crop yields and metal uptakes

International Nuclear Information System (INIS)

Bhogal, A.; Nicholson, F.A.; Chambers, B.J.; Shepherd, M.A.

2003-01-01

Topsoil extractable zinc and copper concentrations are a good indicator of metal bioavailability to crops. - The effect of heavy metal additions in past sewage sludge applications on soil metal availability and the growth and yield of crops was evaluated at two sites in the UK. At Gleadthorpe, sewage sludges enriched with salts of zinc (Zn), copper (Cu) and nickel (Ni) had been applied to a loamy sand in 1982 and additionally naturally contaminated Zn and Cu sludge cakes in 1986. At Rosemaund, sewage sludges naturally contaminated with Zn, Cu, Ni and chromium (Cr) had been applied in 1968-1971 to a sandy loam. From 1994 to 1997, the yields of both cereals and legumes at Gleadthorpe were up to 3 t/ha lower than the no-sludge control where total topsoil Zn and Cu concentrations exceeded 200 and 120 mg/kg, respectively, but only when topsoil ammonium nitrate extractable metal levels also exceeded 40 mg/kg Zn and 0.9 mg/kg Cu. At Rosemaund, yields were only decreased where total topsoil Cu concentrations exceeded 220 mg/kg or 0.7 mg/kg ammonium nitrate extractable Cu. These results demonstrate the importance of measuring extractable as well as total heavy metal concentrations in topsoils when assessing likely effects on plant yields and metal uptakes, and setting soil quality criteria

Contamination and comprehensive risk assessment of heavy metals in Liangtan River, Chongqing, China

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Lei Wang

2016-10-01

Full Text Available Distribution and fraction of heavy metals (Pb, Cr, Zn, and Mn in water and sediment in Liangtan River, Chongqing was analyzed using the atomic absorption spectrometry method. Pearson correlation coefficient, bioavailability index, geoaccumulation index and potential ecological risk index were introduced to classify the source and assess the environmental risk of the heavy metal. Pb, Cr, and Zn mainly existed in residual fraction and fraction bounded to Fe–Mn oxides while Mn mainly existed in the fraction bounded to carbonates and the residual fraction. Mn and Pb, Zn and Cr in the sediment were confirmed originating from, separate common sources. Igeo and $E_\\text{r}^{i}$ were both in the order of Pb > Zn > Cr > Mn. Geoaccumulation indexes demonstrated that the Liangtan River has been heavily polluted by Pb and Zn with the class of 2–4 and 2–3, independently. From viewpoint of the whole Liangtan River, the mean RI (45.1 belonged to low risk level.

Do constructed wetlands remove metals or increase metal bioavailability?

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Xu, Xiaoyu; Mills, Gary L

2018-07-15

The H-02 wetland was constructed to treat building process water and storm runoff water from the Tritium Processing Facility on the Department of Energy's Savannah River Site (Aiken, SC). Monthly monitoring of copper (Cu) and zinc (Zn) concentrations and water quality parameters in surface waters continued from 2014 to 2016. Metal speciation was modeled at each sampling occasion. Total Cu and Zn concentrations released to the effluent stream were below the NPDES limit, and the average removal efficiency was 65.9% for Cu and 71.1% for Zn. The metal-removal processes were found out to be seasonally regulated by sulfur cycling indicated by laboratory and model results. High temperature, adequate labile organic matter, and anaerobic conditions during the warm months (February to August) favored sulfate reduction that produced sulfide minerals to significantly remove metals. However, the dominant reaction in sulfur cycling shifted to sulfide oxidation during the cool months (September to next March). High concentrations of metal-organic complexes were observed, especially colloidal complexes of metal and fulvic acid (FA), demonstrating adsorption to organic matter became the primary process for metal removal. Meanwhile, the accumulation of metal-FA complexes in the wetland system will cause negative effects to the surrounding environment as they are biologically reactive, highly bioavailable, and can be easily taken up and transferred to ecosystems by trophic exchange. Copyright © 2018 Elsevier Ltd. All rights reserved.

Heavy metal pollution in vegetables grown in the vicinity of a multi-metal mining area in Gejiu, China: total concentrations, speciation analysis, and health risk.

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Li, Yanyan; Wang, Hongbin; Wang, Haijuan; Yin, Fei; Yang, Xiaoyan; Hu, Yongjun

2014-11-01

A field survey was conducted to investigate the present situation and health risk of arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) in soils and vegetables in a multi-metal mining area, Gejiu, China. Furthermore, three vegetables (water spinach, potato, and summer squash) containing high metal concentrations were selected to further analyze metal speciation. The results showed that the average concentrations of five metals in soil exceeded the limiting values, and their bioavailable concentrations were significantly positively correlated to the total ones. Heavy metals in the edible parts of vegetables also exceeded the corresponding standards. The leaves of pakchoi, peppermint, and coriander had a strong metal-accumulative ability and they were not suitable for planting. Except the residue forms, the main forms of metals in the edible parts of three selected vegetables were ethanol-, NaCl-, and HAc-extractable fractions for As, Pb, and Cd, respectively; however, Cu was mainly presented as NaCl-extractable and Zn as HAc-extractable fractions. A high proportion of ethanol-extractable As showed that As bioactivity and toxic effects were the highest. Although the total and bioavailable Cd were high in soil, its speciation in vegetables was mainly presented as HAc-extractable fraction, which has a relatively low bioactivity. Lead and arsenic were imposing a serious threat on the local residents via vegetable consumption.

Assessment of heavy metals pollution using AVS-SEM and fractionation techniques in Edku Lagoon sediments, Mediterranean Sea, Egypt.

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El Zokm, Gehan M; Okbah, Mohamed A; Younis, Alaa M

2015-01-01

A method is presented to evaluate the fractionation of metals (Fe, Zn, Cu, Pb, Cd and Ni), acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) in Edku lagoon sediments. Thirteen sediment samples were collected from the study area in the period of 2010-2011 to assess the potential bioavailability and toxicity of the selected metals. According to classification of the Interim Sediment Quality Quidelines (ISQG), five stations near the drains exhibited 10% toxic probability. The high AVS and low ∑SEM ranges in Summer were identified as 6-138 and 0.86-3.3 µmol g(-1) dry wet, respectively which are referring to the low mobility of heavy metals in this season and vice versa for winter (2.5-23.9 and 1.16-3.82 µmol g(-1) dry wet, respectively). According to the evaluation of USEPA, all sediment samples showed ∑SEM/AVS heavy metals in Edku lagoon sediments posed a low risk of adverse biological effects due to cadmium, copper, lead, nickel and zinc in all evaluated stations.

Stormwater impact in Guanabara Bay (Rio de Janeiro): Evidences of seasonal variability in the dynamic of the sediment heavy metals

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Fonseca, E. M.; Baptista Neto, J. A.; Silva, C. G.; McAlister, J. J.; Smith, B. J.; Fernandez, M. A.

2013-09-01

Guanabara Bay is one of the most prominent coastal bays in Brazil. This environment is an estuary of 91 rivers and channels, surrounded by the metropolis of Rio de Janeiro. The bay receives considerable amounts of contaminants introduced from sewage effluents, industrial discharge, urban and agricultural runoff, atmospheric fallout, and the combined inputs from the rivers, making Guanabara Bay one of the most polluted coastal environments on the Brazilian coastline. The aim of this work is to study the concentration and fractionation of the heavy metals within the sediments of the bay. In order to understand the possible seasonal influence on the heavy metal fractionation, two campaigns were carried out in two different seasons of the year (rainy and dry). Twelve stations, in four different areas, with different oceanographic characteristics, where chosen. To assess the bioavailability of the metals a selective extraction procedure was used to study the geochemical fractionation and bioavailability of Zn, Cu, Cr, Ni and Pb. The rainy season was very important with respect to variation in the total concentrations of Cr, Ni and Pb and their fractionation within different "operational" phases present in Guanabara Bay sediments. The water-soluble phase showed little importance, with respect to metal adsorption and this would suggest very low mobility of metals in the water column. Nevertheless, the potentially available metals within these sediments showed a high probability for their release and therefore cause contamination of the water column, since different parts of the bay are constantly subjected to dredging projects promoted by the harbor authorities.

On the bioavailability of trace metals in surface sediments: a combined geochemical and biological approach.

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Roosa, Stéphanie; Prygiel, Emilie; Lesven, Ludovic; Wattiez, Ruddy; Gillan, David; Ferrari, Benoît J D; Criquet, Justine; Billon, Gabriel

2016-06-01

The bioavailability of metals was estimated in three river sediments (Sensée, Scarpe, and Deûle Rivers) impacted by different levels of Cu, Cd, Pb, and Zn (Northern France). For that, a combination of geochemistry and biological responses (bacteria and chironomids) was used. The results obtained illustrate the complexity of the notion of "bioavailability." Indeed, geochemical indexes suggested a low toxicity, even in surface sediments with high concentrations of total metals and a predicted severe effect levels for the organisms. This was also suggested by the abundance of total bacteria as determined by DAPI counts, with high bacterial cell numbers even in contaminated areas. However, a fraction of metals may be bioavailable as it was shown for chironomid larvae which were able to accumulate an important quantity of metals in surface sediments within just a few days.We concluded that (1) the best approach to estimate bioavailability in the selected sediments is a combination of geochemical and biological approaches and that (2) the sediments in the Deûle and Scarpe Rivers are highly contaminated and may impact bacterial populations but also benthic invertebrates.

Heavy metals in municipal solid waste deposits

Energy Technology Data Exchange (ETDEWEB)

Flyhammar, P.

1997-12-01

Extensive use of heavy metals in modern society influences routes followed by fluxes on the surface of the Earth. The changed flow paths may be harmful for the balance of biological systems at different levels, micro-organisms, human beings and whole ecosystems, since the toxicity of heavy metals is determined by their concentrations and chemical forms. Despite the low mobility of heavy metals (Zn, Cu, Pb, Cr, Ni and Cd) in municipal landfills, it was found that extensive transformations of the binding forms of heavy metal take place within the waste mass during the degradation of the waste. These changes appear to be closely related to the development of early diagenetic solid phases, i.e. new secondary solid phases formed in the waste. The heavy metals often constitute a minor part of these phases and the bindings include several forms such as adsorption, complexation, coprecipitation, precipitation, etc. It was also found that the associations between heavy metals and solid phases are dominated by several binding forms to one specific substrate rather than bindings to various solid phases. The mobility of iron and manganese seems to increase during the processes involved in waste degradation due to the solution of oxide/hydroxide phases, while the heavy metals appear to become less mobile due to their binding to organic compounds and sulphides. However, one exception in this case may be nickel. Another aspect of the transformation of heavy metals is the accumulation of pools of heavy metals which can become susceptible to environmental changes, such as oxidation or acidification. However, the risk of increased mobilization caused by lower pH values seem to be limited since municipal solid waste has a large buffer capacity. 66 refs, 9 figs, 3 tabs 66 refs, 9 figs, 3 tabs

Toxic responses of cytochrome P450 sub-enzyme activities to heavy metals exposure in soil and correlation with their bioaccumulation in Eisenia fetida.

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Cao, Xiufeng; Bi, Ran; Song, Yufang

2017-10-01

The dose- and time- dependent responses of cytochrome P450 (CYP) sub-enzyme activities to heavy metals in soil, and the relationships between biomarker responses and metal bioaccumulation in Eisenia fetida were evaluated. Earthworms were exposed to soils spiked with increasing doses of Cd, Cu, Pb or Zn for 21 d. Results demonstrated that EROD and CYP3A4 activities responded significantly with increasing dose and exposure duration. EROD activity significantly (P metal burdens had significant correlation with the total metal concentrations in soil (P metal concentration in soil. The order of metal bioavailability to E. fetida was Cd > Zn > Cu > Pb. CYP3A4 activity in Pb-exposed earthworms had a significant correlation with the accumulated metal (P heavy metals exposure, and we also concluded that different biomarkers with multiple durations could be conducted in the eco-toxicological diagnosis of soil pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Bioremoval of heavy metals by bacterial biomass.

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Aryal, Mahendra; Liakopoulou-Kyriakides, Maria

2015-01-01

Heavy metals are among the most common pollutants found in the environment. Health problems due to the heavy metal pollution become a major concern throughout the world, and therefore, various treatment technologies such as reverse osmosis, ion exchange, solvent extraction, chemical precipitation, and adsorption are adopted to reduce or eliminate their concentration in the environment. Biosorption is a cost-effective and environmental friendly technique, and it can be used for detoxification of heavy metals in industrial effluents as an alternative treatment technology. Biosorption characteristics of various bacterial species are reviewed here with respect to the results reported so far. The role of physical, chemical, and biological modification of bacterial cells for heavy metal removal is presented. The paper evaluates the different kinetic, equilibrium, and thermodynamic models used in bacterial sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions and regeneration of biomass are also discussed.

The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

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Grobelak, Anna; Napora, Anna

2015-01-01

Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and

The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

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Anna Grobelak

Full Text Available Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry and inorganic amendments (lime, superphosphate, and potassium phosphate on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1. A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the

Effects of Medium-Term Amendment with Diversely Processed Sewage Sludge on Soil Humification—Mineralization Processes and on Cu, Pb, Ni, and Zn Bioavailability

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Gabriella Rossi

2018-03-01

Full Text Available The organic fraction of sewage sludge administered to agricultural soil can contribute to slowing down the loss of soil’s organic carbon and, in some cases, can improve the physical and mechanical properties of the soil. One of the main constraints to the agricultural use of sewage sludge is its heavy metals content. In the long term, agricultural administration of sewage sludge to soil could enhance the concentration of soil heavy metals (as total and bioavailable fractions. The aim of this research was to evaluate the effects of medium-term fertilization with diversely processed sewage sludge on the soil’s organic carbon content and humification–mineralization processes, on the physical–mechanical properties of soil and their influence on the pool of potentially bioavailable heavy metals, in order to assess their effectiveness as soil organic amendments. After eight years of sludge administration; an increase in the concentrations of bioavailable form was evidenced in all the heavy metals analyzed; independently of the type of sludge administered. The form of sludge administration (liquid, dehydrated, composted has differently influenced the soil humification–mineralization processes and the physical–mechanical properties of soil. The prolonged amendment with composted sewage sludge contributed to keeping the soil humification–mineralization process in equilibrium and to improving the physical and mechanical qualities of the treated soil.

Bioremediation of Toxic Heavy Metals: A Patent Review.

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Verma, Neelam; Sharma, Rajni

2017-01-01

The global industrialization is fulfilling the demands of modern population at the cost of environmental exposure to various contaminants including heavy metals. These heavy metals affect water and soil quality. Moreover, these enter into the food chain and exhibit their lethal effects on the human health even when present at slightly higher concentration than required for normal metabolism. To the worst of their part, the heavy metals may become carcinogenic. Henceforth, the efficient removal of heavy metals is the demand of sustainable development. Remedy: Bioremediation is the 'green' imperative technique for the heavy metal removal without creating secondary metabolites in the ecosystem. The metabolic potential of several bacterial, algal, fungal as well as plant species has the efficiency to exterminate the heavy metals from the contaminated sites. Different strategies like bioaccumulation, biosorption, biotransformation, rhizofilteration, bioextraction and volatilization are employed for removal of heavy metals by the biological species. Bioremediation approach is presenting a splendid alternate for conventional expensive and inefficient methods for the heavy metal removal. The patents granted on the bioremediation of toxic heavy metals are summarized in the present manuscript which supported the applicability of bioremediation technique at commercial scale. However, the implementation of the present information and advanced research are mandatory to further explore the concealed potential of biological species to resume the originality of the environment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Transfer of heavy metals through terrestrial food webs: a review.

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Gall, Jillian E; Boyd, Robert S; Rajakaruna, Nishanta

2015-04-01

Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal accumulation in animals including behavior, physiology, and diet. Biotic effects of heavy metals are often quite different for essential and non-essential heavy metals, and vary depending on the specific metal involved. They also differ for adapted organisms, including metallophyte plants and heavy metal-tolerant insects, which occur in naturally high-metal habitats (such as serpentine soils) and have adaptations that allow them to tolerate exposure to relatively high concentrations of some heavy metals. Some metallophyte plants are hyperaccumulators of certain heavy metals and new technologies using them to clean metal-contaminated soil (phytoextraction) may offer economically attractive solutions to some metal pollution challenges. These new technologies provide incentive to catalog and protect the unique biodiversity of habitats that have naturally high levels of heavy metals.

Heavy Metal Poisoning and Cardiovascular Disease

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Eman M. Alissa

2011-01-01

Full Text Available Cardiovascular disease (CVD is an increasing world health problem. Traditional risk factors fail to account for all deaths from CVD. It is mainly the environmental, dietary and lifestyle behavioral factors that are the control keys in the progress of this disease. The potential association between chronic heavy metal exposure, like arsenic, lead, cadmium, mercury, and CVD has been less well defined. The mechanism through which heavy metals act to increase cardiovascular risk factors may act still remains unknown, although impaired antioxidants metabolism and oxidative stress may play a role. However, the exact mechanism of CVD induced by heavy metals deserves further investigation either through animal experiments or through molecular and cellular studies. Furthermore, large-scale prospective studies with follow up on general populations using appropriate biomarkers and cardiovascular endpoints might be recommended to identify the factors that predispose to heavy metals toxicity in CVD. In this review, we will give a brief summary of heavy metals homeostasis, followed by a description of the available evidence for their link with CVD and the proposed mechanisms of action by which their toxic effects might be explained. Finally, suspected interactions between genetic, nutritional and environmental factors are discussed.

Bioassessment of heavy metal toxicity and enhancement of heavy metal removal by sulfate-reducing bacteria in the presence of zero valent iron.

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Guo, Jing; Kang, Yong; Feng, Ying

2017-12-01

A simple and valid toxicity evaluation of Zn 2+ , Mn 2+ and Cr 6+ on sulfate-reducing bacteria (SRB) and heavy metal removal were investigated using the SRB system and SRB+Fe 0 system. The heavy metal toxicity coefficient (β) and the heavy metal concentration resulting in 50% inhibition of sulfate reduction (I) from a modeling process were proposed to evaluate the heavy metal toxicity and nonlinear regression was applied to search for evaluation indices β and I. The heavy metal toxicity order was Cr 6+  > Mn 2+  > Zn 2+ . Compared with the SRB system, the SRB+Fe 0 system exhibited a better capability for sulfate reduction and heavy metal removal. The heavy metal removal was above 99% in the SRB+Fe 0 system, except for Mn 2+ . The energy-dispersive spectroscopy (EDS) analysis showed that the precipitates were removed primarily as sulfide for Zn 2+ and hydroxide for Mn 2+ and Cr 6+ .The method of evaluating the heavy metal toxicity on SRB was of great significance to understand the fundamentals of the heavy metal toxicity and inhibition effects on the microorganism and regulate the process of microbial sulfate reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioavailability of cyanide and metal-cyanide mixtures to aquatic life.

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Redman, Aaron; Santore, Robert

2012-08-01

Cyanide can be toxic to aquatic organisms, and the U.S. Environmental Protection Agency has developed ambient water-quality criteria to protect aquatic life. Recent work suggests that considering free, rather than total, cyanide provides a more accurate measure of the biological effects of cyanides and provides a basis for water-quality criteria. Aquatic organisms are sensitive to free cyanide, although certain metals can form stable complexes and reduce the amount of free cyanide. As a result, total cyanide is less toxic when complexing metals are present. Cyanide is often present in complex effluents, which requires understanding how other components within these complex effluents can affect cyanide speciation and bioavailability. The authors have developed a model to predict the aqueous speciation of cyanide and have shown that this model can predict the toxicity of metal-cyanide complexes in terms of free cyanide in solutions with varying water chemistry. Toxicity endpoints based on total cyanide ranged over several orders of magnitude for various metal-cyanide mixtures. However, predicted free cyanide concentrations among these same tests described the observed toxicity data to within a factor of 2. Aquatic toxicity can be well-described using free cyanide, and under certain conditions the toxicity was jointly described by free cyanide and elevated levels of bioavailable metals. Copyright © 2012 SETAC.

Influence of Rapeseed Cake on Heavy Metal Uptake by a Subsequent Rice Crop After Phytoextraction Using Sedum plumbizincicola.

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Zhou, Liqiang; Wu, Longhua; Li, Zhu; Yang, Bingfan; Yin, Bin; Luo, Yongming; Christie, Peter

2015-01-01

A glasshouse pot experiment was conducted to study the effects of phytoextraction by Sedum plumbizincicola and application of rapeseed cake (RSC) on heavy metal accumulation by a subsequent rice (Oryza sativa L.) crop in a contaminated paddy soil collected from east China. After phytoextraction by S. plumbizincicola the soil and brown rice Cd concentrations effectively declined. After phytoextraction, RSC application reduced brown rice Cd concentrations in the subsequent rice crop to 0.23-0.28 mg kg(-1), almost down to the standard limit (0.2 mg kg(-1)). After phytoextraction and then application of RSC, the soil solution pH, dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentrations increased during early stages of rice growth resulting directly and indirectly in lowering the bioavailability of the heavy metals. Thus the grain yield of the subsequent rice crop increased and the heavy metals in the brown rice declined significantly. In this contaminated acid soil, growing the hyperaccumulator S. plumbizincicola and rice in rotation together with RSC application may therefore be regarded as a viable strategy for safe grain production and bioremediation.

Influence of eutrophication on metal bioaccumulation and oral bioavailability in oysters, Crassostrea angulata.

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Li, Shun-Xing; Chen, Li-Hui; Zheng, Feng-Ying; Huang, Xu-Guang

2014-07-23

Oysters (Crassostrea angulata) are often exposed to eutrophication. However, how these exposures influence metal bioaccumulation and oral bioavailability (OBA) in oysters is unknown. After a four month field experimental cultivation, bioaccumulation factors (BAF) of metals (Fe, Cu, As, Cd, and Pb) from seawater to oysters and metal oral bioavailability in oysters by bionic gastrointestinal tract were determined. A positive effect of macronutrient (nitrate N and total P) concentration in seawater on BAF of Cd in oysters was observed, but such an effect was not significant for Fe, Cu, Pb, and As. Only OBA of As was significantly positively correlated to N and P contents. For Fe, OBA was negatively correlated with N. The regular variation of the OBA of Fe and As may be due to the effect of eutrophication on the synthesis of metal granules and heat-stable protein in oysters, respectively.

Adsorption of heavy metal ions on different clays

International Nuclear Information System (INIS)

Kruse, K.

1992-01-01

The aim of the present dissertation is to study the adsorption of heavy metal ions (Cd 2+ , Cu 2+ , Pb 2+ , Zn 2+ ) and their mixtures on clays. Different clays and bentonites (Ca 2+ -bentonite, activated Na + -bentonite, special heavy metal adsorber bentonite, two organophilic bentonites and a mixed layer clay) were used. The adsorbed metal ions were desorbed by appropriate solutions of HCl, EDTA and dioctadecyl dimethylammonium bromide. High concentrations of the heavy metal ions in the solutions can be reached. The desorption guarantees economical recycling. After desorption the clays were used (up to three times) for purification of contaminated water. The best experimental conditions, i.e. the highest adsorption of heavy metal ions from aqueous solutions was found for the greatest ratio of adsorbent/adsorbate. The adsorption was very fast. Calcium, sodium bentonites and the heavy metal adsorber bentonite attained the highest adsorption and desorption for Cu 2+, Zn 2+ and Pb 2+ ions. Cd 2+ ions were only absorbed by Silitonit, a special heavy metal absorber bentonite. The mixed layer clay (Opalit) ranges in adsorption and desorption properties below the unmodified Ca 2+ -bentonite (Montigel) or the activated Na + -bentonite. Only Tixosorb and Tixogel (organophilic bentonites) reach the lowest value of heavy metal adsorption. Only lead cations which are characterised by good polarizability were adsorbed at higher rates, therefore the organophilic bentonites are not appropriate for adsorption of heavy metal ions from aqueous solutions. Mixing of the metal ions generally decreases the adsorption of Pb 2+ and increases the adsorption of Cd 2+ . From mixtures if heavy metal ions adsorption and desorption of Cu 2+ ions reached a maximum for all clays. (author) figs., tabs., 56 refs

Atmospheric heavy metal deposition in the Copenhagen area

Energy Technology Data Exchange (ETDEWEB)

Andersen, A; Hovmand, M F; Johnsen, I

1978-10-01

Transport of heavy metals from the atmosphere to the soil and vegetation takes place by dust fall, bulk precipitation, and gas/aerosol adsorption processes. Atmospheric dry and wet deposition of the heavy metals lead, zinc, nickel, vanadium, iron, and copper over the Copenhagen area was measured by sampling in plastic funnels from 17 stations throughout the area for 12 months. Epigeic bryophytes, epiphytic lichen, and topsoil samples were analyzed. A linear correlation between bulk precipitation and heavy metal concentration in lichens and bryophytes was found. An exponential correlation between bulk precipitation and heavy metal concentration in soil was noted. Regional variation of the heavy metal levels in the Copenhagen area was described, and three sub-areas with high metal burdens were distinguished. (10 diagrams, 8 graphs, 13 references, 2 tables)

Speciation and distribution characteristics of heavy metals and pollution assessments in the sediments of Nashina Lake, Heilongjiang, China.

Science.gov (United States)

Li, Miao; Zang, Shuying; Xiao, Haifeng; Wu, Changshan

2014-05-01

Sediment core samples from Nashina Lake, Heilongjiang, China were collected using a gravity sampler. The cores were sliced horizontally at 1 cm each to determine the particle size, total concentrations and speciation of Cd, Cr, Cu, Mn, Ni, Pb, and Zn. Total concentrations of heavy metals were extracted using an acid mixture (containing hydro fluoric acid, nitric acid, and sulphuric acid) and analyzed using an inductively coupled plasma spectrometry. A sequential extraction procedure was employed to separate chemical species. Analysis of results indicate that the concentrations of heavy metals in the sediments of Nashina Lake in descending order are Mn, Cr, Zn, Pb, Ni, Cu, and Cd. The ratios of the average concentrations of four heavy metals (e.g.Cr, Cu, Ni, Zn) to their background values were >1; and those of Mn, Cd, and Pb were >1. Moreover, some toxic metals were mainly distributed in bioavailable fractions. For instance, both Cd and Mn were typically found in Acid-extractable species or Fe-Mn oxide species, and thus can be easily remobilized and enter the food chain. Finally, the analysis of geo-accumulation index showed that anthropogenic pollution levels of Cr, Cu, Mn, Ni, Zn were low, but those of Pb and Cd were at the moderate level. As both Pb and Cd are toxic metals, it is highly necessary to prohibit their transformation and accumulation in the sediments.

Climate change driven plant-metal-microbe interactions.

Science.gov (United States)

Rajkumar, Mani; Prasad, Majeti Narasimha Vara; Swaminathan, Sandhya; Freitas, Helena

2013-03-01

Various biotic and abiotic stress factors affect the growth and productivity of crop plants. Particularly, the climatic and/or heavy metal stress influence various processes including growth, physiology, biochemistry, and yield of crops. Climatic changes particularly the elevated atmospheric CO₂ enhance the biomass production and metal accumulation in plants and help plants to support greater microbial populations and/or protect the microorganisms against the impacts of heavy metals. Besides, the indirect effects of climatic change (e.g., changes in the function and structure of plant roots and diversity and activity of rhizosphere microbes) would lead to altered metal bioavailability in soils and concomitantly affect plant growth. However, the effects of warming, drought or combined climatic stress on plant growth and metal accumulation vary substantially across physico-chemico-biological properties of the environment (e.g., soil pH, heavy metal type and its bio-available concentrations, microbial diversity, and interactive effects of climatic factors) and plant used. Overall, direct and/or indirect effects of climate change on heavy metal mobility in soils may further hinder the ability of plants to adapt and make them more susceptible to stress. Here, we review and discuss how the climatic parameters including atmospheric CO₂, temperature and drought influence the plant-metal interaction in polluted soils. Other aspects including the effects of climate change and heavy metals on plant-microbe interaction, heavy metal phytoremediation and safety of food and feed are also discussed. This review shows that predicting how plant-metal interaction responds to altering climatic change is critical to select suitable crop plants that would be able to produce more yields and tolerate multi-stress conditions without accumulating toxic heavy metals for future food security. Copyright © 2012 Elsevier Ltd. All rights reserved.

Heavy metal contamination in some mining communities within the Jimi River basin in Ashanti Region, Ghana

International Nuclear Information System (INIS)

Akabzaa, T.M.; Banoeng-Yakubu, B.; Seyire, J.S.

2005-01-01

The study assesses heavy metals contamination of some communities along the Jim River Basin in the Ashanti Region. The Jim River Basin is within the mining concession of Ashanti Goldfields Company (AGC) Limited, now Anglogold Ashanti. The selected communities receive drainage and effluent from mining, processing and waste containment facilities of AGC and from the activities of illegal small scale miners (galamseys) in the area. Representative samples of water from streams, boreholes, hand-dug wells, stream and over bank sediments, and fruits were analyzed for Mn, Cu, Zn, Ni, Pb and Cd using the Unicam 969 Atomic Absorption Spectrometer (AAS). Fe was determined by ion chromatography, As by an ARL 341 hydride-generator and Hg by cold vapour Atomic Fluorescence Spectrometry. Protracted periods of underground mining, recent extensive surface mining and intensified illegal mining activities were identified as major sources of augmented levels of heavy metals in water, sediment and fruit samples. Sediments and fruits exhibit higher concentration of determined metals than water. Cu, Cd, Zn, and Ni, are generally low in water samples, while Fe, As and Mn are generally high, particularly in stream water and ranged from < 0.002 to 17.100mg/l, 0.001 to 6.318mg/l and <0.001 to 2.584mg/l respectively. Metal concentrations were highest in sediments. Fe values in sediments ranged from 2210-50180 mg/kg and averaged 28270mg/kg, Hg between 0.26 to 3.02 mg/kg and averaged 1.21mg/kg while arsenic ranged between 0.24-to 7591.58mg/kg and averaged 1746.51mg/kg. Heavy metals in fruit samples were considered indicative of their bioavailability. Some fruits showed extremely high concentrations Hg, Zn and As. High heavy metal concentrations are generally coincident with areas of past and/ or of active mining and processing activities. (author)

A sensitive whole-cell biosensor for the simultaneous detection of a broad-spectrum of toxic heavy metal ions.

Science.gov (United States)

Cerminati, S; Soncini, F C; Checa, S K

2015-04-07

Bacterial biosensors are simple, cost-effective and efficient analytical tools for detecting bioavailable heavy metals in the environment. This work presents the design, construction and calibration of a novel whole-cell fluorescent biosensory device that, simultaneously and with high sensitivity, reports the presence of toxic mercury, lead, cadmium and/or gold ions in aqueous samples. This bio-reporter can be easily applied as an immediate alerting tool for detecting the presence of harmful pollutants in drinking water.

Measurement of soil lead bioavailability and influence of soil types and properties: A review.

Science.gov (United States)

Yan, Kaihong; Dong, Zhaomin; Wijayawardena, M A Ayanka; Liu, Yanju; Naidu, Ravi; Semple, Kirk

2017-10-01

Lead (Pb) is a widespread heavy metal which is harmful to human health, especially to young children. To provide a human health risk assessment that is more relevant to real conditions, Pb bioavailability in soils is increasingly employed in the assessment procedure. Both in vivo and in vitro measurements for lead bioavailability are available. In vivo models are time- consuming and expensive, while in vitro models are rapid, economic, reproducible, and reliable while involving more uncertainties. Uncertainties in various measurements create difficulties in accurately predicting Pb bioavailability, resulting in the unnecessary remediation of sites. In this critical review, we utilised available data from in vivo and in vitro studies to identify the key parameters influencing the in vitro measurements, and presented uncertainties existing in Pb bioavailability measurements. Soil type, properties and metal content are reported to influence lead bioavailability; however, the differences in methods for assessing bioavailability and the differences in Pb source limit one's ability to conduct statistical analyses on influences of soil factors on Pb bioavailability. The information provided in the review is fundamentally useful for the measurement of bioavailability and risk assessment practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of heavy metals on soil microbial community

Science.gov (United States)

Chu, Dian

2018-02-01

Soil is one of the most important environmental natural resources for human beings living, which is of great significance to the quality of ecological environment and human health. The study of the function of arable soil microbes exposed to heavy metal pollution for a long time has a very important significance for the usage of farmland soil. In this paper, the effects of heavy metals on soil microbial community were reviewed. The main contents were as follows: the effects of soil microbes on soil ecosystems; the effects of heavy metals on soil microbial activity, soil enzyme activities and the composition of soil microbial community. In addition, a brief description of main methods of heavy metal detection for soil pollution is given, and the means of researching soil microbial community composition are introduced as well. Finally, it is concluded that the study of soil microbial community can well reflect the degree of soil heavy metal pollution and the impact of heavy metal pollution on soil ecology.

Ecological risk assessment and source identification for heavy metals in surface sediment from the Liaohe River protected area, China.

Science.gov (United States)

Ke, Xin; Gui, Shaofeng; Huang, Hao; Zhang, Haijun; Wang, Chunyong; Guo, Wei

2017-05-01

Surface sediment samples collected from 19 sites in the Liaohe River protected area were analysed for heavy metals to evaluate their potential ecological risk. The results demonstrated that the degree of pollution from seven heavy metals decreases in the following sequence: cadmium(Cd)>arsenic(As)>copper(Cu)>nickel(Ni)>lead(Pb)>chromium(Cr)>zinc(Zn). The metal speciation analysis indicated that Cd, Pb and Zn were dominated by non-residual fractions and have high mobility and bioavailability, indicating significant anthropogenic sources. Based on the potential ecological risk index (PERI), geo-accumulation index (I geo ) and risk assessment code (RAC), Cd made the most dominant contribution, with a high to very high potential ecological risk being determined in this studied area. Moreover, in reference to the results of multivariate statistical analyses, we deduced that Cd and Zn originated from agriculture sources within the Liaohe River protected area, whereas Cu, Cr and Ni primarily originated from natural sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioavailability of metals-trace in sediments: a review; Biodisponibilidade de metais-traco em sedimentos: uma revisao

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Rafaela E. de A.V.; Souza, Vivianne Lucia Bormann; Lima, Vanessa Lemos de; Hazin, Clovis Abrahao, E-mail: rafaelarodriguesss@hotmail.com, E-mail: vlsouza@cnen.gov.br, E-mail: lemos.nessa@yahoo.com.br, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

2014-07-01

The chemical association of metals in sediments provides an indication of its release by physical, chemical and biological processes, with toxic effects under certain environmental conditions. Knowing about their chemical bonds in sediments, can recognize specific sources of pollution, and speciation of trace metals is important for bioavailability and toxicity to animals and plants. The accumulation of these particles in the sediment occur by the following mechanisms: a) adsorption to the finest particles; b) precipitating of the element in the form of compounds; c) co-precipitating of the element with iron and manganese oxides; d) complexation with organic matter; e) incorporation into the crystal lattice of minerals. Currently, five phases are considered when studying the bioavailability of trace elements in sediments: a) the exchangeable phase, MgCl{sub 2} (causes saltiness change); b) leachable phase, (acetic acid causes pH change); c) reducible phase (hydroxylamine hydrochloride causes release of the bound metals linked to Fe and Mn oxides); d) oxidized phase, the peroxide hydrogen (cause the degradation of organic matter); e) the residual pseudo-phase, the aqua regia (cause release of metals associated to minerals). The first three phases are considered the most bioavailable. In the last two fractions, the metals are linked to sediment constituents and not bioavailable. The organic phase is relatively stable and the metal present therein are removed under oxidative conditions. Metals present in the pseudo-phase residual measure the degree of environmental pollution, since great amount of metals at this stage indicates a lower degree of pollution.

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

DEFF Research Database (Denmark)

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

2003-01-01

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

Biomonitoring of trace metal bioavailabilities to the barnacle Amphibalanus amphitrite along the Iranian coast of the Persian Gulf.

Science.gov (United States)

Nasrolahi, A; Smith, B D; Ehsanpour, M; Afkhami, M; Rainbow, P S

2014-10-01

The fouling barnacle Amphibalanus amphitrite is a cosmopolitan biomonitor of trace metal bioavailabilities, with an international comparative data set of body metal concentrations. Bioavailabilities of As, Cd, Cr, Cu, Fe, Mn, Pb, V and Zn to A. amphitrite were investigated at 19 sites along the Iranian coast of the understudied Persian Gulf. Commercial and fishing ports showed extremely high Cu bioavailabilities, associated with high Zn bioavailabilities, possibly from antifouling paints and procedures. V availability was raised at one port, perhaps associated with fuel leakage. Cd bioavailabilities were raised at sites near the Strait of Hormuz, perhaps affected by adjacent upwelling off Oman. The As data allow a reinterpretation of the typical range of accumulated As concentrations in A. amphitrite. The Persian Gulf data add a new region to the A. amphitrite database, confirming its importance in assessing the ecotoxicologically significant trace metal contamination of coastal waters across the world. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sewage sludge pyrolysis - the distribution of heavy metals

Energy Technology Data Exchange (ETDEWEB)

Kistler, R.; Widmer, F.; Brunner, P.

1986-01-01

The paper informs about the heavy metal contents of sewage sludges and discusses the origin of household, industry and surface sewerage of the respective heavy metals. The study aimed at assessing whether and in how far heavy metal volatility may be checked by reducing the temperature during sewage sludge pyrolysis. The testing equipment used was made of glass/silica glass. Instead of in particles heavy metals were precipitated in the gaseous state. Except from mercury heavy metals are retained by the ashes up to temperatures from 450 to 555/sup 0/C. Due to the persistence of mercury care should be taken to keep the sewerage clear of it from the very beginning. Emissions caused by reactor materials can be avoided by choosing appropriate pyrolysis reactors.

Toxicity of heavy metals in the environment

National Research Council Canada - National Science Library

Oehme, F.W

1978-01-01

... as the fundamental mechanisms of toxicity resulting from heavy metal chemicals. The more common toxic heavy metals, along with their biochemistry and associated clinical syndromes, are then described...

Bioavailability of particulate metal to zebra mussels: Biodynamic modelling shows that assimilation efficiencies are site-specific

Energy Technology Data Exchange (ETDEWEB)

Bourgeault, Adeline, E-mail: bourgeault@ensil.unilim.fr [Cemagref, Unite de Recherche Hydrosystemes et Bioprocedes, 1 rue Pierre-Gilles de Gennes, 92761 Antony (France); FIRE, FR-3020, 4 place Jussieu, 75005 Paris (France); Gourlay-France, Catherine, E-mail: catherine.gourlay@cemagref.fr [Cemagref, Unite de Recherche Hydrosystemes et Bioprocedes, 1 rue Pierre-Gilles de Gennes, 92761 Antony (France); FIRE, FR-3020, 4 place Jussieu, 75005 Paris (France); Priadi, Cindy, E-mail: cindy.priadi@eng.ui.ac.id [LSCE/IPSL CEA-CNRS-UVSQ, Avenue de la Terrasse, 91198 Gif-sur-Yvette (France); Ayrault, Sophie, E-mail: Sophie.Ayrault@lsce.ipsl.fr [LSCE/IPSL CEA-CNRS-UVSQ, Avenue de la Terrasse, 91198 Gif-sur-Yvette (France); Tusseau-Vuillemin, Marie-Helene, E-mail: Marie-helene.tusseau@ifremer.fr [IFREMER Technopolis 40, 155 rue Jean-Jacques Rousseau, 92138 Issy-Les-Moulineaux (France)

2011-12-15

This study investigates the ability of the biodynamic model to predict the trophic bioaccumulation of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) in a freshwater bivalve. Zebra mussels were transplanted to three sites along the Seine River (France) and collected monthly for 11 months. Measurements of the metal body burdens in mussels were compared with the predictions from the biodynamic model. The exchangeable fraction of metal particles did not account for the bioavailability of particulate metals, since it did not capture the differences between sites. The assimilation efficiency (AE) parameter is necessary to take into account biotic factors influencing particulate metal bioavailability. The biodynamic model, applied with AEs from the literature, overestimated the measured concentrations in zebra mussels, the extent of overestimation being site-specific. Therefore, an original methodology was proposed for in situ AE measurements for each site and metal. - Highlights: > Exchangeable fraction of metal particles did not account for the bioavailability of particulate metals. > Need for site-specific biodynamic parameters. > Field-determined AE provide a good fit between the biodynamic model predictions and bioaccumulation measurements. - The interpretation of metal bioaccumulation in transplanted zebra mussels with biodynamic modelling highlights the need for site-specific assimilation efficiencies of particulate metals.

Impact of heavy metal on activity of some microbial enzymes in the riverbed sediments: Ecotoxicological implications in the Ganga River (India).

Science.gov (United States)

Jaiswal, Deepa; Pandey, Jitendra

2018-04-15

We studied the extracellular enzyme activity (EEA) in the riverbed sediment along a 518km gradient of the Ganga River receiving carbon and nutrient load from varied human sources. Also, we tested, together with substrate-driven stimulation, if the heavy metal accumulated in the sediment inhibits enzyme activities. Because pristine values are not available, we considered Dev Prayag, a least polluted site located 624km upstream to main study stretch, as a reference site. There were distinct increases in enzyme activities in the sediment along the study gradient from Dev Prayag, however, between-site differences were in concordance with sediment carbon(C), nitrogen (N) and phosphorus (P). Fluorescein diacetate hydrolysis (FDAase), β-glucosidase (Glu) and protease activities showed positive correlation with C, N and P while alkaline phosphatase was found negatively correlated with P. Enzyme activities were found negatively correlated with heavy metal, although ecological risk index (E R i ) varied with site and metal species. Dynamic fit curves showed significant positive correlation between heavy metal and microbial metabolic quotient (qCO 2 ) indicating a decrease in microbial activity in response to increasing heavy metal concentrations. This study forms the first report linking microbial enzyme activities to regional scale sediment heavy metal accumulation in the Ganga River, suggests that the microbial enzyme activities in the riverbed sediment were well associated with the proportion of C, N and P and appeared to be a sensitive indicator of C, N and P accumulation in the river. Heavy metal accumulated in the sediment inhibits enzyme activities, although C rich sediment showed relatively low toxicity due probably to reduced bioavailability of the metal. The study has relevance from ecotoxicological as well as from biomonitoring perspectives. Copyright © 2017 Elsevier Inc. All rights reserved.

Heavy metal pollution in coastal areas of South China: A review

International Nuclear Information System (INIS)

Wang, Shuai-Long; Xu, Xiang-Rong; Sun, Yu-Xin; Liu, Jin-Ling; Li, Hua-Bin

2013-01-01

Highlights: • Heavy metal contamination in coastal areas of South China has been reviewed. • Heavy metal levels were closely related to economic development in past decades. • Heavy metal levels from Hong Kong continually decreased from the early 1990s. • Higher concentrations of heavy metals were found in mollusk. • Levels of heavy metals in part of seafood exceeded the safety limit. -- Abstract: Coastal areas of South China face great challenges due to heavy metal contamination caused by rapid urbanization and industrialization. In this paper, more than 90 articles on levels, distributions, and sources of heavy metals in sediments and organisms were collected to review the status of heavy metal pollution along coastal regions of South China. The results show that heavy metal levels were closely associated with local economic development. Hong Kong and the Pearl River Estuary were severely contaminated by heavy metals. However, concentrations of heavy metals in sediments from Hong Kong have continually decreased since the early 1990s. High levels of heavy metals were found in biota from Lingdingyang in Guangdong province. Mollusks had higher concentrations of heavy metals than other species. Human health risk assessments suggested that levels of heavy metals in some seafood from coastal areas of South China exceeded the safety limit

MICROBIAL REMOVAL OF HEAVY METALS FROM WASTEWATER

Directory of Open Access Journals (Sweden)

Justyna Koc-Jurczyk

2014-10-01

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

Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

Science.gov (United States)

Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

2015-02-15

Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

Monitoring of some heavy metal in egypt using different spectroscopic technique ICP-AES and AAS-GF

International Nuclear Information System (INIS)

El-Sayed, A.A.

2005-01-01

Heavy metals include both toxic and/or non toxic elements egyptian aquatic environment were monitored using inductivly coupled plasma-atomic emission spectroscopy; ICP-AES and graphite furnace-atomic absorption spectroscopy; GF-AAS. Water and aquatic weeds (waterhyathins) are of different categories specified for such monitoring form the canals. The locations of sampling sites the river nile in egypt. These sites were chosen based on the industrial activity comparing to the cleansite and the other cultivated one. Bioavailability and related effects were defined so as to specify actually the higher concentration more contaminated areas

Behaviour of heavy metals in soils

NARCIS (Netherlands)

Harmsen, K.

1977-01-01

Fractions of Zn, Cd, Cu, Pb, Fe and Mn extractable with water, a salt solution and dilute acid, and residual fractions were determined in soils with raised contents of heavy metals, near zinc smelters, along a river formerly discharging heavy metals, and in a sewage farm. Special attention

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.

Modeling of Heavy Metal Transformation in Soil Ecosystem

Science.gov (United States)

Kalinichenko, Kira; Nikovskaya, Galina N.

2017-04-01

The intensification of industrial activity leads to an increase in heavy metals pollution of soils. In our opinion, sludge from biological treatment of municipal waste water, stabilized under aerobic-anaerobic conditions (commonly known as biosolid), may be considered as concentrate of natural soil. In their chemical, physical and chemical and biological properties these systems are similar gel-like nanocomposites. These contain microorganisms, humic substances, clay, clusters of nanoparticles of heavy metal compounds, and so on involved into heteropolysaccharides matrix. It is known that microorganisms play an important role in the transformation of different nature substances in soil and its health maintenance. The regularities of transformation of heavy metal compounds in soil ecosystem were studied at the model of biosolid. At biosolid swelling its structure changing (gel-sol transition, weakening of coagulation contacts between metal containing nanoparticles, microbial cells and metabolites, loosening and even destroying of the nanocomposite structure) can occur [1, 2]. The promotion of the sludge heterotrophic microbial activities leads to solubilization of heavy metal compounds in the system. The microbiological process can be realized in alcaligeneous or acidogeneous regimes in dependence on the type of carbon source and followed by the synthesis of metabolites with the properties of flocculants and heavy metals extragents [3]. In this case the heavy metals solubilization (bioleaching) in the form of nanoparticles of hydroxycarbonate complexes or water soluble complexes with oxycarbonic acids is observed. Under the action of biosolid microorganisms the heavy metals-oxycarbonic acids complexes can be transformed (catabolised) into nano-sizing heavy metals- hydroxycarbonates complexes. These ecologically friendly complexes and microbial heteropolysaccharides are able to interact with soil colloids, stay in the top soil profile, and improve soil structure due

Effects of alkaline and bioorganic amendments on cadmium, lead, zinc, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals.

Science.gov (United States)

He, Huaidong; Tam, Nora F Y; Yao, Aijun; Qiu, Rongliang; Li, Wai Chin; Ye, Zhihong

2016-12-01

Paddy soils and rice (Oryza sativa L.) contaminated by mixed heavy metals have given rise to great concern. Field experiments were conducted over two cultivation seasons to study the effects of steel slag (SS), fly ash (FA), limestone (LS), bioorganic fertilizer (BF), and the combination of SS and BF (SSBF) on rice grain yield, Cd, Pb, and Zn and nutrient accumulation in brown rice, bioavailability of Cd, Pb, and Zn in soil as well as soil properties (pH and catalase), at two acidic paddy fields contaminated with mixed heavy metals (Cd, Pb, and Zn). Compared to the controls, SS, LS, and SSBF at both low and high additions significantly elevated soil pH over both cultivation seasons. The high treatments of SS and SSBF markedly increased grain yields, the accumulation of P and Ca in brown rice and soil catalase activities in the first cultivation season. The most striking result was from SS application (4.0 t ha -1 ) that consistently and significantly reduced the soil bioavailability of Cd, Pb, and Zn by 38.5-91.2 % and the concentrations of Cd and Pb in brown rice by 20.9-50.9 % in the two soils over both cultivation seasons. LS addition (4.0 t ha -1 ) also markedly reduced the bioavailable Cd, Pb, and Zn in soil and the Cd concentrations in brown rice. BF remobilized soil Cd and Pb leading to more accumulation of these metals in brown rice. The results showed that steel slag was most effective in the remediation of acidic paddy soils contaminated with mixed heavy metals.

Potential of Brassic rapa, Cannabis sativa, Helianthus annuus and Zea mays for phytoextraction of heavy metals from calcareous dredged sediment derived soils.

Science.gov (United States)

Meers, E; Ruttens, A; Hopgood, M; Lesage, E; Tack, F M G

2005-10-01

Remediation of soil pollution is one of the many current environmental challenges. Anthropogenic activity has resulted in the contamination of extended areas of land, the remediation of which is both invasive and expensive by conventional means. Phytoextraction of heavy metals from contaminated soils has the prospect of being a more economic in situ alternative. In addition, phytoextraction targets ecotoxicologically the most relevant soil fraction of these metals, i.e. the bioavailable fraction. Greenhouse experiments were carried out to evaluate the potential of four high biomass crop species in their potential for phytoextraction of heavy metals, with or without with the use of soil amendments (EDTA or EDDS). A calcareous dredged sediment derived surface soil, with high organic matter and clay content and moderate levels of heavy metal pollution, was used in the experiments. No growth depression was observed in EDTA or EDDS treated pots in comparison to untreated controls. Metal accumulation was considered to be low for phytoextraction purposes, despite the use of chelating agents. The low observed shoot concentrations of heavy metals were attributed to the low phytoavailability of heavy metals in this particular soil substrate. The mobilising effects induced by EDTA in the soil were found to be too long-lived for application as a soil amendment in phytoextraction. Although EDDS was found to be more biodegradable, higher effect half lives were observed than reported in literature or observed in previous experiments. These findings caution against the use of any amendment, biodegradable or otherwise, without proper investigation of its effects and the longevity thereof.

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

Science.gov (United States)

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

2005-01-01

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

Geochemical Assessment and Spatial Analysis of Heavy Metals in the Surface Sediments in the Eastern Beibu Gulf: A Reflection on the Industrial Development of the South China Coast

Science.gov (United States)

Lin, Jing; Qian, Bihua; Wu, Zhai; Huang, Peng; Chen, Kai; Li, Tianyao; Cai, Minggang

2018-01-01

The Beibu Gulf (also named the Gulf of Tonkin), located in the northwest of the South China Sea, is representative of a bay suffering from turbulence and contamination associated with rapid industrialization and urbanization. In this study, we aim to provide the novel baseline levels of heavy metals for the research area. Concentrations of five heavy metals (i.e., Cu, Pb, Zn, Cd and Cr) were determined in surface sediments from 35 sites in the eastern Beibu Gulf. The heavy metal content varied from 6.72 to 25.95 mg/kg for Cu, 16.99 to 57.98 mg/kg for Pb, 73.15 to 112.25 mg/kg for Zn, 0.03 to 0.12 mg/kg for Cd, and 20.69 to 56.47 mg/kg for Cr, respectively. With respect to the Chinese sediment quality criteria, sediments in the eastern Beibu Gulf have not been significantly affected by coastal metal pollutions. The results deduced from the geoaccumulation index (Igeo) showed that the study area has been slightly polluted by Pb, which might be caused by non-point sources. Relatively high concentrations of Cu, Pb and Cd were found around the coastal areas of Guangxi province, the Leizhou Peninsula and the northwest coast of Hainan Island, whereas the highest concentrations of Zn and Cr were found on the northwest coast of Hainan Island. Spatial distribution patterns of the heavy metals showed that bioavailable fractions of Pb were higher than in the residual fractions, while Cu and Cd concentrations in exchangeable and carbonate fractions were relatively higher than those in the bioavailable fractions. Hierarchical clustering analysis suggested that the sampling stations could be separated into three groups with different geographical distributions. Accompanying their similar spatial distribution in the study area, significant correlation coefficients among Cu, Cd and Pb were also found, indicating that these three metals might have had similar sources. Overall, the results indicated that the distribution of these heavy metals in the surface sediments collected from

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.

Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

Energy Technology Data Exchange (ETDEWEB)

Xiao, Rong [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); School of Nature Conservation, Beijing Forestry University, Beijing 100083 (China); Bai, Junhong, E-mail: junhongbai@163.com [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China)

2015-06-01

The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

International Nuclear Information System (INIS)

Xiao, Rong; Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui

2015-01-01

The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

Heavy Metal Blood Test: MedlinePlus Lab Test Information

Science.gov (United States)

... this page: https://medlineplus.gov/labtests/heavymetalbloodtest.html Heavy Metal Blood Test To use the sharing features ... this page, please enable JavaScript. What is a Heavy Metal Blood Test? A heavy metal blood test ...

Heavy metal distribution and partitioning in the vicinity of the discharge areas of Lisbon drainage basins (Tagus Estuary, Portugal)

Science.gov (United States)

Duarte, Bernardo; Silva, Gilda; Costa, José Lino; Medeiros, João Paulo; Azeda, Carla; Sá, Erica; Metelo, Inês; Costa, Maria José; Caçador, Isabel

2014-10-01

Worldwide estuarine ecosystems are by their privileged geographic location, anthropogenically impacted systems. Heavy metal contamination in estuarine waters and sediments are well known to be one of the most important outcomes driven from human activities. The partitioning of these elements has been widely focused, due to its importance not only on the estuarine biogeochemistry but also on its bioavailability to the trophic webs. As observed in other estuaries, in the Tagus basin, no increase in the partition coefficients with the increasing suspended particulate matter concentrations was observed, mostly due to a permanent dilution process of the suspended matter, rich in heavy metals and less contaminated and resuspended bottom sediments. Another important outcome of this study was the common origin of all the analysed heavy metals, probably due to the large industrialization process that the margins of the Tagus estuary suffered in the past, although no relationship was found with the presence of the different discharge areas. In fact, metal partitioning seems to be mostly influenced by the chemical species in which the pollutant is delivered to the system and on water chemistry, with a higher emphasis on the metal cycling essentially between the particulate and dissolved phase. This partitioning system acquires a relevant importance while evaluating the impacts of marine construction and the associated dredging operations, and consequent changes in the estuarine water chemistry.

Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer

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Wenzhen Yuan

2016-01-01

Full Text Available With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1 Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS damage. (2 Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3 Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4 Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8 and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective.

Microbial treatment of heavy metal leachates

International Nuclear Information System (INIS)

Alvarez Aliaga, M. T.

2009-01-01

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

Biosorption of heavy metals from wastewater by biosolids

Energy Technology Data Exchange (ETDEWEB)

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

2006-08-15

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

Remediation of multiple heavy metal-contaminated soil through the combination of soil washing and in situ immobilization.

Science.gov (United States)

Zhai, Xiuqing; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Huang, Mei; Zhang, Qiu; Zeng, Guangming

2018-09-01

The remediation of heavy metal-contaminated soils is a great challenge for global environmental sciences and engineering. To control the ecological risks of heavy metal-contaminated soil more effectively, the present study focused on the combination of soil washing (with FeCl 3 ) and in situ immobilization (with lime, biochar, and black carbon). The results showed that the removal rate of Cd, Pb, Zn, and Cu was 62.9%, 52.1%, 30.0%, and 16.7%, respectively, when washed with FeCl 3 . After the combined remediation (immobilization with 1% (w/w) lime), the contaminated soils showed 36.5%, 73.6%, 70.9%, and 53.4% reductions in the bioavailability of Cd, Cu, Pb, and Zn (extracted with 0.11M acetic acid), respectively, than those of the soils washed with FeCl 3 only. However, the immobilization with 1% (w/w) biochar or 1% (w/w) carbon black after washing exhibited low effects on stabilizing the metals. The differences in effects between the immobilization with lime, biochar, and carbon black indicated that the soil pH had a significant influence on the lability of heavy metals during the combined remediation process. The activity of the soil enzymes (urease, sucrase, and catalase) showed that the addition of all the materials, including lime, biochar, and carbon black, exhibited positive effects on microbial remediation after soil washing. Furthermore, lime was the most effective material, indicating that low soil pH and high acid-soluble metal concentrations might restrain the activity of soil enzymes. Soil pH and nutrition were the major considerations for microbial remediation during the combined remediation. These findings suggest that the combination of soil washing and in situ immobilization is an effective method to amend the soils contaminated with multiple heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

Microalgae - A promising tool for heavy metal remediation.

Science.gov (United States)

Suresh Kumar, K; Dahms, Hans-Uwe; Won, Eun-Ji; Lee, Jae-Seong; Shin, Kyung-Hoon

2015-03-01

Biotechnology of microalgae has gained popularity due to the growing need for novel environmental technologies and the development of innovative mass-production. Inexpensive growth requirements (solar light and CO2), and, the advantage of being utilized simultaneously for multiple technologies (e.g. carbon mitigation, biofuel production, and bioremediation) make microalgae suitable candidates for several ecofriendly technologies. Microalgae have developed an extensive spectrum of mechanisms (extracellular and intracellular) to cope with heavy metal toxicity. Their wide-spread occurrence along with their ability to grow and concentrate heavy metals, ascertains their suitability in practical applications of waste-water bioremediation. Heavy metal uptake by microalgae is affirmed to be superior to the prevalent physicochemical processes employed in the removal of toxic heavy metals. In order to evaluate their potential and to fill in the loopholes, it is essential to carry out a critical assessment of the existing microalgal technologies, and realize the need for development of commercially viable technologies involving strategic multidisciplinary approaches. This review summarizes several areas of heavy metal remediation from a microalgal perspective and provides an overview of various practical avenues of this technology. It particularly details heavy metals and microalgae which have been extensively studied, and provides a schematic representation of the mechanisms of heavy metal remediation in microalgae. Copyright © 2014 Elsevier Inc. All rights reserved.

Heavy metal decontamination of sludges and soils. Pt. 2

International Nuclear Information System (INIS)

Niemann, J.

1993-06-01

This research project deals with decontamination technology for contaminated soil and sediments. A pilot plant for the decontamination of soil contaminated with heavy metals has been erected and is operated. The process is arranged in two steps: - heavy metal contaminated solid is decontaminted with acidic extraction. - the heavy metals are separated in a recyclable formation from the process solution you gain in the first process step. Heavy metal contaminated soil, heavy metal contaminated sediments (habour sediments) as well as residue from a soil regeneration plant have been successfully decontaminated in the pilot plan. An adaption of the process is necessary for various materials. High rates of mobilisation of heavy metals (e.g. lead, cadmium, chromium, copper, nickel, zinc) were obtained, especially with soil which contains less organic matter. (orig.). 54 figs., 30 tabs., 45 refs [de

Macroalgal biomonitors of trace metal contamination in acid sulfate soil aquaculture ponds.

Science.gov (United States)

Gosavi, K; Sammut, J; Gifford, S; Jankowski, J

2004-05-25

Earthen shrimp aquaculture ponds are often impacted by acid sulfate soils (ASS), typically resulting in increased disease and mortality of cultured organisms. Production losses have been attributed to either low pH or to elevated concentrations of toxic metals, both direct products of pyrite oxidation in ASS. The standard farm management practice to minimise effects of pyrite oxidation is to maintain pH of pond waters above 5, based on the assumption that dissolved metal bioavailability is negligible at this pH. This study aimed to test the validity of this assumption, and therefore elucidate a possible role of toxic heavy metals in observed decreases in farm productivity. Metal bioaccumulation in four genera of macroalgae, Ulva sp., Enteromorpha sp., Cladophora sp. and Chaetomorpha sp., sampled from ASS-affected shrimp aquaculture ponds were measured using inductively coupled plasma-optical emission spectroscopy (ICP-OES) to assess the relative bioavailability of dissolved metals within the system. Results showed that all four genera of macroalgae accumulated appreciable quantities of Fe, Al, Zn, Cd, Cu, As and Pb. Iron and Al, the most common metals mobilised from ASS, were both accumulated in all algal genera to concentrations three orders of magnitude greater than all other metals analysed. These findings indicate that dissolved heavy metals are indeed bioavailable within the aquaculture pond system. A literature search of heavy metal bioaccumulation by these algal genera revealed concentrations recorded in this study are comparable to highly contaminated environments, such as those exposed to urban, industrial and mining pollution. The results of this study indicate that dissolved metal bioavailability in many earthen shrimp aquaculture ponds may be higher than previously thought.

Dynamics of arbuscular mycorrhizal symbiosis in heavy metal phytoremediation: Meta-analytical and conceptual perspectives

International Nuclear Information System (INIS)

Audet, Patrick; Charest, Christiane

2007-01-01

To estimate dynamics of arbuscular mycorrhizal (AM) symbiosis in heavy metal (HM) phytoremediation, we conducted a literature survey and correlated HM uptake and relative plant growth parameters from published data. After estimating AM feedback responses for these parameters at low and high soil-HM concentration intervals, we determined that the roles of AM symbiosis are characterized by (1) an increased HM phytoextraction via mycorrhizospheric 'Enhanced Uptake' at low soil-HM concentrations, and (2) a reduced HM bioavailability via AM fungal 'Metal-Binding' processes at high soil-HM levels, hence resulting in increased plant biomass and enhanced plant tolerance through HM stress-avoidance. We present two conceptual models which illustrate the important compromise between plant growth, plant HM uptake and HM tolerance, and further emphasize the importance of AM symbiosis in buffering the soil environment for plants under such stress conditions. - This meta-analysis has revealed a transition role of the AM symbiosis in phytoremediation shifting from 'Enhanced Uptake' to 'Metal-Binding' beyond critical soil-HM levels

Hydroponics reducing effluent's heavy metals discharge.

Science.gov (United States)

Rababah, Abdellah; Al-Shuha, Ahmad

2009-01-01

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

Evaluation of trace metals bioavailability in Japanese river waters using DGT and a chemical equilibrium model.

Science.gov (United States)

Han, Shuping; Naito, Wataru; Hanai, Yoshimichi; Masunaga, Shigeki

2013-09-15

To develop efficient and effective methods of assessing and managing the risk posed by metals to aquatic life, it is important to determine the effects of water chemistry on the bioavailability of metals in surface water. In this study, we employed the diffusive gradients in thin-films (DGT) to determine the bioavailability of metals (Ni, Cu, Zn, and Pb) in Japanese water systems. The DGT results were compared with a chemical equilibrium model (WHAM 7.0) calculation to examine its robustness and utility to predict dynamic metal speciation. The DGT measurements showed that biologically available fractions of metals in the rivers impacted by mine drainage and metal industries were relatively high compared with those in urban rivers. Comparison between the DGT results and the model calculation indicated good agreement for Zn. The model calculation concentrations for Ni and Cu were higher than the DGT concentrations at most sites. As for Pb, the model calculation depended on whether the precipitated iron(III) hydroxide or precipitated aluminum(III) hydroxide was assumed to have an active surface. Our results suggest that the use of WHAM 7.0 combined with the DGT method can predict bioavailable concentrations of most metals (except for Pb) with reasonable accuracy. Copyright © 2013. Published by Elsevier Ltd.

Background concentrations and reference values for heavy metals in soils of Cuba.

Science.gov (United States)

Alfaro, Mirelys Rodríguez; Montero, Alfredo; Ugarte, Olegario Muñiz; do Nascimento, Clístenes Williams Araújo; de Aguiar Accioly, Adriana Maria; Biondi, Caroline Miranda; da Silva, Ygor Jacques Agra Bezerra

2015-01-01

The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.

Improving the relationship between soil characteristics and metal bioavailability by using reactive fractions of soil parameters in calcareous soils.

Science.gov (United States)

de Santiago-Martín, Ana; van Oort, Folkert; González, Concepción; Quintana, José R; Lafuente, Antonio L; Lamy, Isabelle

2015-01-01

The contribution of the nature instead of the total content of soil parameters relevant to metal bioavailability in lettuce was tested using a series of low-polluted Mediterranean agricultural calcareous soils offering natural gradients in the content and composition of carbonate, organic, and oxide fractions. Two datasets were compared by canonical ordination based on redundancy analysis: total concentrations (TC dataset) of main soil parameters (constituents, phases, or elements) involved in metal retention and bioavailability; and chemically defined reactive fractions of these parameters (RF dataset). The metal bioavailability patterns were satisfactorily explained only when the RF dataset was used, and the results showed that the proportion of crystalline Fe oxides, dissolved organic C, diethylene-triamine-pentaacetic acid (DTPA)-extractable Cu and Zn, and a labile organic pool accounted for 76% of the variance. In addition, 2 multipollution scenarios by metal spiking were tested that showed better relationships with the RF dataset than with the TC dataset (up to 17% more) and new reactive fractions involved. For Mediterranean calcareous soils, the use of reactive pools of soil parameters rather than their total contents improved the relationships between soil constituents and metal bioavailability. Such pool determinations should be systematically included in studies dealing with bioavailability or risk assessment. © 2014 SETAC.

Heavy metals in Mindhola river estuary, India

Digital Repository Service at National Institute of Oceanography (India)

Zingde, M.D.; Rokade, M.A; Mandalia, A

The heavy metal concentrations are studied along the Mindhola river estuary. Surface and bottom water samples were collected using Niskin Sampler. The sediment samples were collected using a Van Veen grab. The heavy metal concentration is estimated...

Heavy Metal Pollution Around International Hatay Airport

Directory of Open Access Journals (Sweden)

Abdullah Özkan

2017-02-01

Full Text Available In this study, it was aimed to determine the heavy metal pollution in the agricultural lands around Hatay airport and travel possible alteration in the amount of heavy metal on the land in accordance with the distance to the airport. For this purpose, the airport was chosen as the center and 27 soil samples were obtained around the airport at 2 km intervals in depth ranging from 0 to 30 cm. Lead (Pb, cadmium (Cd, nickel (Ni, chrome (Cr, cobalt (Co, aluminium (Al, iron (Fe, copper (Cu, manganese (Mn and zinc (Zn elements in soil samples were analysed using MP-AES instrument by DTPA method. (3 repetition for each sample. As a result of the analysis, heavy metal concentrations were found as Pb 0-1.45 mg/kg, Cd 0-0.220 mg/kg, Ni 0-3.95 mg/kg, Cr 0-0.780 mg/kg, Co 0-0.270 mg/kg, Al 0-0.700 mg/kg, Fe 1.47- 16.2 mg/kg, Cu 0.400-5.35 mg/kg, Mn 0-19 mg/kg and Zn 0.050-3.14 mg/kg. When comparing the obtained data through this study with allowable concentrations of heavy metals in soil of Environment and Forest Directorates Guidance, it was determined that the heavy metal concentration of the soil does not pose any problems in terms of heavy metal pollution. Besides, iron concentration was decreased when the distance to the airport is increased.

Remediation of biochar on heavy metal polluted soils

Science.gov (United States)

Wang, Shuguang; Xu, Yan; Norbu, Namkha; Wang, Zhan

2018-01-01

Unreasonable mining and smelting of mineral resources, solid waste disposal, sewage irrigation, utilization of pesticides and fertilizers would result in a large number of heavy metal pollutants into the water and soil environment, causing serious damage to public health and ecological safety. In recent years, a majority of scholars tried to use biochar to absorb heavy metal pollutants, which has some advantages of extensive raw material sources, low-cost and high environmental stability. This paper reviewed the definition, properties of biochar, the mechanism of heavy metal sorption by biochar and some related problems and prospects, to provide some technical support for the application of biochar into heavy metal polluted soils.

Distribution of heavy metals in Tamshui mangrove forest ecosystem

Energy Technology Data Exchange (ETDEWEB)

Chiu, C Y; Chou, C H

1990-06-01

Tamsui estuary area is one of the few places in Taiwan where mangrove is still growing. Heavy metals, carried by the water of the Tamsui river, are accumulated in the estuary soil. Most heavy metals in soil, however, are immobile under reducing conditions and are fixed in the large amount of organic matter present. Heavy metals are distributed at different concentrations in various tissues of Kandelia candel as well as grasses of Phragmites communis, Imperata cylindrica, and Cyperus malaccensis growing in the swamp area. The concentration of heavy metals was significantly higher root than in stems and leaves. The absorption of heavy metals by the plants was less in soil that was frequently submerged. Kandelia candel seems to have no special tolerance to copper and zinc. The soil environment which favors reduced availability of heavy metals may help Kandelia candel adapt to growth in the polluted estuary.

HEAVY METALS IN VINEYARDS AND ORCHARD SOILS

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GUSTAVO BRUNETTO

Full Text Available ABSTRACT The application of foliar fungicides in vineyards and orchards can increase soil concentration of heavy metals such as copper (Cu and zinc (Zn, up to the toxicity threshold for fruit trees and cover crops. However, some agronomic practices, such as liming, addition of organic fertilizers, cultivation of soil cover crops and inoculation of young plants with arbuscular mycorrhizal fungi can decrease the availability and the potential of heavy metal toxicity to fruit trees. This review aims to compile and present information about the effects of increasing concentrations of heavy metals, especially Cu and Zn, on soils cultivated with fruit trees and provides some agronomic practices of remediation. Information about the sources of heavy metals found in soils cultivated with fruit trees are presented; mechanisms of absorption, transport, accumulation and potential toxicity to plants are described.

A review of phytoremediation technology: heavy metals uptake by plants

Science.gov (United States)

Sumiahadi, A.; Acar, R.

2018-03-01

Heavy metal is one of the serious environmental pollutions for now days as impact of industrial development in several countries. Heavy metals give toxic effects on human health and cause several serious diseases. Several techniques have been using for removing heavy metal contaminants from the environmental but these techniques have limitations such as high cost, long time, logistical problems and mechanical complexity. Phytoremediation can be used as an alternative solution for heavy metal remediation process because of its advantages as a cost-effective, efficient, environment- and eco-friendly technology based on the use of metal-accumulating plants. According to previous studies, several plants have a high potential as heavy metals bioaccumulator and can be used for phytoremediation process of heavy metals.

Bioaccumulation of heavy metals and ecophysiological responses to heavy metal stress in selected populations of Vaccinium myrtillus L. and Vaccinium vitis-idaea L.

Science.gov (United States)

Kandziora-Ciupa, Marta; Nadgórska-Socha, Aleksandra; Barczyk, Gabriela; Ciepał, Ryszard

2017-09-01

The aim of this study was to determine the concentrations of heavy metals (Cd, Pb, Zn, Fe, and Mn) in soil, and their bioavailability and bioaccumulation in Vaccinium myrtillus L. and Vaccinium vitis-idaea L. organs. Analysis also concerned the physiological responses of these plants from three polluted sites (immediate vicinity of a zinc smelter in Miasteczko Śląskie, ArcelorMittal Poland S.A. iron smelter in Dąbrowa Górnicza-Łosień, and Jaworzno III power plant in Jaworzno) and one pseudo-control site (Pazurek nature reserve in Jaroszowiec Olkuski). All of the sites are situated in the southern parts of Poland in the Śląskie or Małopolskie provinces. The contents of proline, non-protein thiols, glutathione, ascorbic acid, and the activity of superoxide dismutase and guaiacol peroxidase in the leaves of Vaccinium myrtillus L. and Vaccinium vitis-idaea L. were measured. In soil, the highest levels of Cd, Pb, and Zn (HNO 3 extracted and CaCl 2 extracted) were detected at the Miasteczko Śląskie site. At all sites a several times lower concentration of the examined metals was determined in the fraction of soil extracted with CaCl 2 . Much higher Cd, Pb, Zn and Fe concentrations were found in V. myrtillus and V. vitis-idaea grown at the most polluted site (located near the zinc smelter) in comparison with cleaner areas; definitely higher bioaccumulation of these metals was found in lingonberry organs. Additionally, we observed a large capability of bilberry to accumulate Mn. Antioxidant response to heavy metal stress also differed between V. myrtillus and V. vitis-idaea. In V. myrtillus we found a positive correlation between the level of non-protein thiols and Cd and Zn concentrations, and also between proline and these metals. In V. vitis-idaea leaves an upward trend in ascorbic acid content and superoxide dismutase activity accompanied an increase in Cd, Pb, and Zn concentrations. At the same time, the increased levels of all tested metals in the leaves

Leaching of heavy metals from timah langat amang

International Nuclear Information System (INIS)

Shukri bin Othman

1990-01-01

Accelerated leaching studies of amang from Timah Langat for heavy metals showed that the material was rather stable. From almost 24 types of heavy metals contained in the material, the metal that leached out most was Al, followed by Pb, U, Cu, Mn, Fe, Mg, Y and La but at smaller quantities. The studies also showed that amang was very porous. The high seepage rate resulted in the solubilities of the metals not reaching equilibrium. In that situation, the leaching of heavy metals from amang was dependent on the seepage rate of water, the height of the material, the volume of water that seeped through and the solubility of the metals

Characterization of a heavy metal translocating P-type ATPase gene from an environmental heavy metal resistance Enterobacter sp. isolate.

Science.gov (United States)

Chien, Chih-Ching; Huang, Chia-Hsuan; Lin, Yi-Wei

2013-03-01

Heavy metals are common contaminants found in polluted areas. We have identified a heavy metal translocating P-type ATPase gene (hmtp) via fosmid library and in vitro transposon mutagenesis from an Enterobacter sp. isolate. This gene is believed to participate in the bacterium's heavy metal resistance traits. The complete gene was identified, cloned, and expressed in a suitable Escherichia coli host cell. E. coli W3110, RW3110 (zntA::Km), GG48 (ΔzitB::Cm zntA::Km), and GG51 (ΔzitB::Cm) were used to study the possible effects of this gene for heavy metal (cadmium and zinc in particular) resistance. Among the E. coli strains tested, RW3110 and GG48 showed more sensitivity to cadmium and zinc compared to the wild-type E. coli W3110 and strain GG51. Therefore, strains RW3110 and GG48 were chosen for the reference hosts for further evaluation of the gene's effect. The results showed that expression of this heavy metal translocating P-type ATPase gene could increase the ability for zinc and cadmium resistance in the tested microorganisms.

Adsorption of heavy metal in freeway by asphalt block

Science.gov (United States)

Zheng, Chaocheng

2017-08-01

Heavy metals are toxic, persistent, and carcinogenic in freeway. Various techniques are available for the removal of heavy metals from waste water among soils during freeway including ion-exchange, membrane filtration, electrolysis, coagulation, flotation, and adsorption. Among them, bio-sorption processes are widely used for heavy metal and other pollutant removal due to its sustainable, rapid and economic. In this paper, heavy metal removal facilitated by adsorption in plants during freeway was illustrated to provide concise information on exploring the adsorption efficiency.

Impact of heavy metals on the female reproductive system

Directory of Open Access Journals (Sweden)

Piotr Rzymski

2015-05-01

Full Text Available Introduction. It has been recognized that environmental pollution can affect the quality of health of the human population. Heavy metals are among the group of highly emitted contaminants and their adverse effect of living organisms has been widely studied in recent decades. Lifestyle and quality of the ambient environment are among these factors which can mainly contribute to the heavy metals exposure in humans. Objective. A review of literature linking heavy metals and the female reproductive system and description of the possible associations with emission and exposure of heavy metals and impairments of female reproductive system according to current knowledge. Results. The potential health disorders caused by chronic or acute heavy metals toxicity include immunodeficiency, osteoporosis, neurodegeneration and organ failures. Potential linkages of heavy metals concentration found in different human organs and blood with oestrogen-dependent diseases such as breast cancer, endometrial cancer, endometriosis and spontaneous abortions, as well as pre-term deliveries, stillbirths and hypotrophy, have also been reported. Conclusions. Environmental deterioration can lead to the elevated risk of human exposure to heavy metals, and consequently, health implications including disturbances in reproduction. It is therefore important to continue the investigations on metal-induced mechanisms of fertility impairment on the genetic, epigenetic and biochemical level.

Bioaccumulation and toxic effects of some heavy metals in ...

African Journals Online (AJOL)

The contamination of the aquatic systems with heavy metals from natural anthropogenic sources has become a global problem which poses threats to ecosystems and natural communities. Hence this study reviews the effects of heavy metals in freshwater fishes. Fishes bioaccumulate heavy metals (including cadmium, zinc ...

Heavy metals effect in Drosophila melanogaster germinal cells

International Nuclear Information System (INIS)

Rosa Duque de la, M.E.

1984-01-01

Heavy metals occur naturally and some of them are very important in cellular metabolism. Industrial development has increased metal concentration in the environment and in the living organisms tissues. This increase promotes the human risk to suffer teratogenesis, carcinogenesis and mutagenesis. Different biological systems have been used to proof the genetic effect of heavy metals including Drosophila. In the present work chromium, cadmium, lead, zinc and arsenic salts were administered to Drosophila females and males adults in order to determine the genetic effect produced by these compounds, in both femenine and masculine germinal cells. The mating system used (''Oster males'' and y 2 wsup(a)/y 2 wsup(a); e/e females) permited to determine among two succesive generations, the mutagenic effects produced by heavy metals in Drosophila. The salts administration to adult flies was made by injection. Non-disjunction, X-chromosome loss, and sex linked recessive lethals frequency was increased by heavy metals. It was observed a fertility disminution between F 1 descendants from individuals treated with the metalic salts. It was demonstrated that heavy metals can interact with genetic material at different levels in the two types of gametic cells to produce genetic damage. (author)

Heavy metal pollution in coastal areas of South China: a review.

Science.gov (United States)

Wang, Shuai-Long; Xu, Xiang-Rong; Sun, Yu-Xin; Liu, Jin-Ling; Li, Hua-Bin

2013-11-15

Coastal areas of South China face great challenges due to heavy metal contamination caused by rapid urbanization and industrialization. In this paper, more than 90 articles on levels, distributions, and sources of heavy metals in sediments and organisms were collected to review the status of heavy metal pollution along coastal regions of South China. The results show that heavy metal levels were closely associated with local economic development. Hong Kong and the Pearl River Estuary were severely contaminated by heavy metals. However, concentrations of heavy metals in sediments from Hong Kong have continually decreased since the early 1990 s. High levels of heavy metals were found in biota from Lingdingyang in Guangdong province. Mollusks had higher concentrations of heavy metals than other species. Human health risk assessments suggested that levels of heavy metals in some seafood from coastal areas of South China exceeded the safety limit. Copyright © 2013 Elsevier Ltd. All rights reserved.

Concentrations of heavy metals in river sediments of the Canes River Basin, the state of Rio de Janeiro, Brazil

International Nuclear Information System (INIS)

De Meneses Silva, M.; Teixeira de Andrade, G.

2010-01-01

Research about chimism in the Bengalas river basin was performed as a part of the environmental study project developed in the area, encompassing several knowledge fields. Among these, Environmental Geochemistry played an important role. This work presents the results related to heavy metals in stream sediments, indicating its origins (natural or anthropic) and its availability for aquatic biota. The basin under study has 135.07 Km2, laying in the oriental portion of the Teresópolis country, 100 Km far from the of Rio de Janeiro city. The rivers forming the Bengalas basin cut Pre-Cambrian terrain, formed by Orthognaiss takes 70% of the area, post-tectonic granite(20%), migmatite gneiss (10%) and gabro dikes. The methodology used was the determination of the content of heavy metals through sequencial extraction technique, consisting in the selective remove of metals in the geochemical fractions found in the sediments, cation exchange (bioavailable), carbonaceous, reducible and organic (potentially bioavailable) and residual (non available).The analyze of the results showed that iron was present in all sequential phases and predominated in the residual phase The same behavior was verified for zinc and copper. Manganese had the best distribution through the fractions due to its redox character, allowing bigger solubility and transportation; it appeared in the exchange, residual, organic and carbonaceous phases. Cadmium was found only in the carbonaceous phase, confirming its geochemical tendency. Chrome, on the other hand, was present in the residual and organic phase, while lead was found in the residual and carbonaceous phase

Heavy metal ions are potent inhibitors of protein folding

International Nuclear Information System (INIS)

Sharma, Sandeep K.; Goloubinoff, Pierre; Christen, Philipp

2008-01-01

Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd 2+ , Hg 2+ and Pb 2+ proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC 50 in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far

Heavy metal bioaccumulation in the soft tissues of the green mussels, Perna viridis (L.) Bivalve: Mytilacea

International Nuclear Information System (INIS)

Borbon, V.X.L.

1991-01-01

Untreated agro-industrial and domestic waste continuously being damped along the shores of its surrounding provinces and cities pollute the Manila Bay coastal waters. Presumably, its oyster and mussel culture farms are contaminated with toxic heavy metals. Yet, this alarming signs remain barely investigated. Pollution enhanced, the bioavailability and toxicity of heavy metals threaten the flora and fauna of the aquatic ecosystem. Trace concentrations of toxic elements in the marine food chain can trigger deleterious biochemical, physiological and ecological impact. Known to be bio-accumulated by aquatic organisms, the mean concentrations of Hg, Cd, Pb, Cu, and Zn in the edible tissues of Perna viridis were determined. Water and sediments sampled from the mussel culture farms were also analyzed. Results revealed that despite the apparent pollution, except for Cu and Zn, which registered slightly higher values, Hg, Cd and Pb concentrations were much lower than the maximum permissible limits. Even water and sediments samples tested showed that mean concentrations of these elements were still below sublethal limits. (auth.). 79 refs.; 8 figs.; 13 tabs.; 16 plates

Optimal selection of biochars for remediating metals ...

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 the bioavailability of the metals at mine sites. Biochar with its potential to complex and immobilize heavy metals, is an emerging alternative for reducing bioavailability. Furthermore, biochar has been reported to improve soil conditions for plant growth and can be used for promoting the establishment of a soil-stabilizing native plant community to reduce offsite movement of metal-laden waste materials. Because biochar properties depend upon feedstock selection, pyrolysis production conditions, and activation procedures used, they can be designed to meet specific remediation needs. As a result biochar with specific properties can be produced to correspond to specific soil remediation situations. However, techniques are needed to optimally match biochar characteristics with metals contaminated soils to effectively reduce metal bioavailability. Here we present experimental results used to develop a generalized method for evaluating the ability of biochar to reduce metals in mine spoil soil from an abandoned Cu and Zn mine. Thirty-eight biochars were produced from approximately 20 different feedstocks and produced via slow pyrolysis or gasification, and were allowed to react with a f

Bioavailability assessment of toxic metals using the technique "acid-volatile sulfide (AVS)-simultaneously extracted metals (SEM)" in marine sediments collected in Todos os Santos Bay, Brazil.

Science.gov (United States)

Silva, Jucelino B; Nascimento, Rodrigo A; de Oliva, Sergio T; de Oliveira, Olívia M C; Ferreira, Sergio L C

2015-10-01

This paper reports the bioavailability of the metals (cadmium, copper, zinc, lead, and nickel) in sediment samples collected in seven stations from the São Paulo Estuary, Todos os Santos Bay, Brazil. The bioavailability was determined by employing the technique "acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM)". The elements cadmium, copper, lead, and zinc were determined using differential pulse anodic stripping voltammetry (DPASV), while nickel was quantified utilizing electrothermal atomic absorption spectrometry (ET AAS). The accuracy of these methods was confirmed using a certified reference material of estuarine sediment (NIST 1646). The sulfide was quantified using potentiometry with selective electrode and the organic matter determination employing an indirect volumetric method using potassium dichromate and iron(II) sulfate solutions. The bioavailability of the metals was estimated by relationship between the concentration of AVS and the sum of the concentrations of the simultaneously extracted metals (ΣSEM), considering a significant toxicity when (ΣSEM)/(AVS) is higher than 1. The bioavailability values in the seven stations studied varied from 0.93 to 1.31 (June, 2014) and from 0.34 to 0.58 (September, 2014). These results demonstrated a critical condition of toxicity (bioavailability >1) in six of the seven sediment samples collected during the rainy season (June, 2014). In the other period (September, 2014), the bioavailability was always lower than 1 for all sediment samples collected in the seven stations. The individual values of the concentrations of the five metals were compared with the parameters PEL (probable effects level) and TEL (threshold effects level), which are commonly employed for characterization of ecological risk in environmental systems. This comparison revealed that all metals have concentrations lower than the PEL and only zinc and lead in some stations have contents higher than the TEL. The

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.

Do high levels of diffuse and chronic metal pollution in sediments of Rhine and Meuse floodplains affect structure and functioning of terrestrial ecosystems?

International Nuclear Information System (INIS)

Rozema, Jelte; Notten, Martje J.M.; Aerts, Rien; Gestel, Cornelis A.M. van; Hobbelen, Peter H.F.; Hamers, Timo H.M.

2008-01-01

This paper (re)considers the question if chronic and diffuse heavy metal pollution (cadmium, copper, lead and zinc) affects the structure and functioning of terrestrial ecosystems of Biesbosch National Park, the floodplain area of rivers Meuse and Rhine. To reach this aim, we integrated the results of three projects on: 1. the origin, transfer and effects of heavy metals in a soil-plant-snail food chain; 2. the impact of bioavailability on effects of heavy metals on the structure and functioning of detritivorous communities; 3. the risk assessment of heavy metals for an herbivorous and a carnivorous small mammal food chain. Metal pollution levels of the Biesbosch floodplain soils are high. The bioavailability of metals in the soils is low, causing low metal levels in plant leaves. Despite this, metal concentrations in soil dwelling detritivores and in land snails at polluted locations are elevated in comparison to animals from 'non-polluted' reference sites. However, no adverse effects on ecosystem structure (species richness, density, biomass) and functioning (litter decomposition, leaf consumption, reproduction) have been found. Sediment metal pollution may pose a risk to the carnivorous small mammal food chain, in which earthworms with elevated metal concentrations are eaten by the common shrew. Additional measurements near an active metal smelter, however, show reduced leaf consumption rates and reduced reproduction by terrestrial snails, reflecting elevated metal bioavailability at this site. Since future management may also comprise reintroduction of tidal action in the Biesbosch area, changes in metal bioavailability, and as a consequence future ecosystem effects, cannot be excluded

Classification of Plants According to Their Heavy Metal Content ...

African Journals Online (AJOL)

Plants like other living organisms respond differently under different environmental conditions. An elevated level of heavy metals is one of the stresses which results into three classes of plants depending on their heavy metal content. The classes of plant species according to their accumulated heavy metals around North ...

Heavy metals in the cell nucleus - role in pathogenesis.

Science.gov (United States)

Sas-Nowosielska, Hanna; Pawlas, Natalia

2015-01-01

People are exposed to heavy metals both in an occupational and natural environment. The most pronounced effects of heavy metals result from their interaction with cellular genetic material packed in form of chromatin. Heavy metals influence chromatin, mimicking and substituting natural microelements in various processes taking place in the cell, or interacting chemically with nuclear components: nucleic acids, proteins and lipids. This paper is a review of current knowledge on the effects of heavy metals on chromatin, exerted at the level of various nuclear components.

EDGA amendment of slightly heavy metal loaded soil affects heavy metal solubility, crop growth and microbivorous nematodes but not bacteria and herbivorous nematodes

NARCIS (Netherlands)

Bouwman, L.A.; Bloem, J.; Römkens, P.F.A.M.; Japenga, J.

2005-01-01

Phytoextraction of heavy metals is a promising technology to remediate slightly and moderately contaminated soils. To enhance crops' uptake of heavy metals, chelates such as EDGA are being tested as soil additives. Heavy metal loaded EDGA can affect soil organisms such as bacteria and nematodes in

Multiple heavy metal removal using an entomopathogenic fungi Beauveria bassiana.

Science.gov (United States)

Gola, Deepak; Dey, Priyadarshini; Bhattacharya, Arghya; Mishra, Abhishek; Malik, Anushree; Namburath, Maneesh; Ahammad, Shaikh Ziauddin

2016-10-01

Towards the development of a potential remediation technology for multiple heavy metals [Zn(II), Cu(II), Cd(II), Cr(VI) and Ni(II)] from contaminated water, present study examined the growth kinetics and heavy metal removal ability of Beauveria bassiana in individual and multi metals. The specific growth rate of B. bassiana varied from 0.025h(-1) to 0.039h(-1) in presence of individual/multi heavy metals. FTIR analysis indicated the involvement of different surface functional groups in biosorption of different metals, while cellular changes in fungus was reflected by various microscopic (SEM, AFM and TEM) analysis. TEM studies proved removal of heavy metals via sorption and accumulation processes, whereas AFM studies revealed increase in cell surface roughness in fungal cells exposed to heavy metals. Present study delivers first report on the mechanism of bioremediation of heavy metals when present individually as well as multi metal mixture by entomopathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gender identity and the electric guitar in heavy metal music

OpenAIRE

Kelly, Philip

2009-01-01

In this chapter I will attempt to outline the gendered characteristics of heavy metal and the electric guitar and address the question: has society’s impression of heavy metal as a primarily masculine pursuit been so imbedded in Western culture that we will never see a female heavy metal band achieve the same level of success as a male heavy metal band?

Heavy metals in packaging : a literature survey

NARCIS (Netherlands)

van Putten EM; IMG

2011-01-01

The use of the heavy metals cadmium, mercury, chromium and lead in packaging is forbidden internationally for some years because these substances are harmful to the environment. In 2002 the Dutch national Inspectorate for the Environment determined the presence of heavy metals in packaging for

A Drinking Water Sensor for Lead and Other Heavy Metals.

Science.gov (United States)

Lin, Wen-Chi; Li, Zhongrui; Burns, Mark A

2017-09-05

Leakage of lead and other heavy metals into drinking water is a significant health risk and one that is not easily detected. We have developed simple sensors containing only platinum electrodes for the detection of heavy metal contamination in drinking water. The two-electrode sensor can identify the existence of a variety of heavy metals in drinking water, and the four-electrode sensor can distinguish lead from other heavy metals in solution. No false-positive response is generated when the sensors are placed in simulated and actual tap water contaminated by heavy metals. Lead detection on the four-electrode sensor is not affected by the presence of common ions in tap water. Experimental results suggest the sensors can be embedded in water service lines for long-time use until lead or other heavy metals are detected. With its low cost (∼$0.10/sensor) and the possibility of long-term operation, the sensors are ideal for heavy metal detection of drinking water.

Effect of heavy metals on growth and heavy metal content of Allium porrum L. and Pisum sativum L

Energy Technology Data Exchange (ETDEWEB)

Gruenhage, L.; Jaeger, H.J.

1985-01-01

The effects of cadmium, lead, zinc and copper, singly and in combination, on yield, heavy metal content and the mineral composition of Allium porrum L. and Pisum sativum L. have been investigated. The Cd, Pb, Zn and Cu concentrations of shoots and roots of Allium porrum increased with increasing heavy metal contamination of soil. However, no visible symptoms of heavy metal toxicity were recognized. The dry matter production was reduced as a function of heavy metal concentration and combination. The mechanisms of combinations were mostly synergistic. The correlation between pollutant contents (nmol/shoot) and yield was higher than the correlation between heavy metal concentrations of soil or shoots (ppm) and yield. Results of regression analyses showed that the inhibition of copper translocation caused by Cd, Pb and Zn was responsible for the yield depressions. The antagonism between Cd and N-deficiency showed that the level of N-supply was without negative effects on yield depressions of Pisum sativum caused by Cd. In contrast to this, the N-form played an important role in Cd-toxicity as the synergism between Cd and NH4 illustrated. K-deficiency as well as acidic nutrient solution (pH=4) diminished the root/shoot-barrier for Cd and therefore Cd-translocation from roots to shoots increased. Concerning calcium, magnesium and iron the decrease of ion uptake caused by Cd was statistically significant higher than yield depression.

A Pooled Data Analysis to Determine the Relationship between Selected Metals and Arsenic Bioavailability in Soil

OpenAIRE

Kaihong Yan; Ravi Naidu; Yanju Liu; Ayanka Wijayawardena; Luchun Duan; Zhaomin Dong

2018-01-01

Chronic exposure to arsenic (As) is a global concern due to worldwide exposure and adverse effects, and the importance of incorporating bioavailability in the exposure assessment and risk assessment of As is increasing acknowledged. The bioavailability of As is impacted by a number of soil properties, such as pH, clay and metal concentrations. By retrieving 485 data from 32 publications, the aim of this study was to determine the relationship between selected metals (Fe and Al) and As bioavai...

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

Science.gov (United States)

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

2015-10-01

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

Phytoremediation of heavy metals with several efficiency enhancer ...

African Journals Online (AJOL)

USER

2010-06-21

Jun 21, 2010 ... Key words: phytoremediation, heavy metal, plant growth promoting rhizobacteria, multi-functional method. ... population in the twentieth century, heavy metal ... This natural and environmental friendly technology is.

Metal transformation as a strategy for bacterial detoxification of heavy metals.

Science.gov (United States)

Essa, Ashraf M M; Al Abboud, Mohamed A; Khatib, Sayeed I

2018-01-01

Microorganisms can modify the chemical and physical characters of metals leading to an alteration in their speciation, mobility, and toxicity. Aqueous heavy metals solutions (Hg, Cd, Pb, Ag, Cu, and Zn) were treated with the volatile metabolic products (VMPs) of Escherichia coli Z3 for 24 h using aerobic bioreactor. The effect of the metals treated with VMPs in comparison to the untreated metals on the growth of E. coli S1 and Staphylococcus aureus S2 (local isolates) was examined. Moreover, the toxic properties of the treated and untreated metals were monitored using minimum inhibitory concentration assay. A marked reduction of the treated metals toxicity was recorded in comparison to the untreated metals. Scanning electron microscopy and energy dispersive X-ray analysis revealed the formation of metal particles in the treated metal solutions. In addition to heavy metals at variable ratios, these particles consisted of carbon, oxygen, sulfur, nitrogen elements. The inhibition of metal toxicity was attributed to the existence of ammonia, hydrogen sulfide, and carbon dioxide in the VMPs of E. coli Z3 culture that might responsible for the transformation of soluble metal ions into metal complexes. This study clarified the capability of E. coli Z3 for indirect detoxification of heavy metals via the immobilization of metal ions into biologically unavailable species. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leaching Properties of Naturally Occurring Heavy Metals from Soils

Science.gov (United States)

Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

2014-12-01

The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with

Effect of heavy metal and EDTA application on heavy metal uptake ...

African Journals Online (AJOL)

Yomi

2012-04-12

Apr 12, 2012 ... Cadmium, lead and ... removal of Cd, Cr, Cu, Ni, Pb, and Zn (Prasad and ... collected for the analysis of heavy metal concentrations of Cd, Cr ... One hundred millgram (100 mg) of leaf tissues ..... Variability for the fatty acid.

Determination of heavy metals in medicinal plants from the wild and cultivated garden in Wilberforce Island, Niger Delta region, Nigeria

Directory of Open Access Journals (Sweden)

Edebi N. Vaikosen

2017-04-01

Full Text Available Context: Adverse effects from herbal medicines may be partly due to the association of heavy metals with medicinal plants. Aims: To determine residual levels of Ni, Cr, Pb and Cd in nine selected medicinal plant species and the surrounding soils collected from the Faculty of Pharmacy medicinal garden and College of Health Sciences residential quarters, Amassoma, Bayelsa state, Nigeria. Methods: Nine plant species: Jatropha tanjorensis, Ipomoea batatas, Celosia argentea, Zea mays, Colocasia esculenta, Corchorus olitorius, Vernonia amygdalina, Ocimum gratissimum and Talinum triangulare were collected with their surrounding soil samples. The samples were dried and subjected to atomic absorption spectrophotometry (AAS to determine the heavy metal concentrations. Results: The detection frequencies of heavy metals in medicinal plants were: Cd – 100%, Pb – 11%, Ni – 0% and Cr – 0%. The residential quarter was more contaminated than cultivated medicinal garden. Order of residual concentration in bulk soils was Cr > Cd > Ni > Pb. Bioaccumulation factor ranged from 0 – 25.93 for foliar tissues. Cadmium in plant species ranged from 0.23 to 2.44 µg/g with > 88% exceeding the WHO maximum limit for medicinal plant materials. Conclusions: The heavy metal concentrations in medicinal plants were dependent on the collection sites, plant species and physico-chemical properties of soil. Cd exhibited the greatest bioavailability in the investigated plants and soils. Cd and Pb found in plant foliage were due to uptake from soil and aerial deposition, respectively.

Fractionation, characterization and speciation of heavy metals in ...

African Journals Online (AJOL)

Speciation of heavy metals in soils determines the availability for metals for plant uptake and potential for contamination of groundwater following application of composts to agricultural lands. Methods used to characterize heavy metals in solid phase of composts and compost amended soils include physical fractionation ...

Estimation of environmental mobility of heavy metals using a sequential leaching of particulate material emitted from an opencast chrome mine complex

Energy Technology Data Exchange (ETDEWEB)

Poeykioe, R. [Meri-Lappi Institute, Centre for Environmental Technology, University of Oulu, Kemi (Finland); Peraemaeki, P.; Kuokkanen, T. [University of Oulu, Department of Chemistry, Oulu (Finland); Vaelimaeki, I. [Suomen Ympaeristoepalvelu Oy, Oulu (Finland)

2002-06-01

A four-stage sequential leaching procedure was applied to assess the bioavailability and environmental mobility of heavy metals (Cr, Fe, Cu, Ni and Cd) in total suspended particulate (TSP) material emitted from an opencast chrome mine complex (Kemi, Northern Finland). TSP material was collected on glass fibre filters by a high-volume sampler, and a sequential leaching procedure was used to determine the distribution of heavy metals between the water-soluble fraction (H{sub 2}O), environmentally mobile fraction (CH{sub 3}COONH{sub 4}), the fraction bound to carbonate and oxides (HONH{sub 3}Cl + CH{sub 3}COOH), and the fraction bound to silicates and organic matter, that is the environmentally immobile fraction (HNO{sub 3} + HF + HCl). The sequential leaching procedure was also applied to the certified reference materials VKI (QC Loam Soil A) and PACS-2 (Marine Sediment) to evaluate the accuracy and reproducibility of the leaching procedure. The heavy metals were determined by graphite furnace atomic absorption spectrometry (GFAAS) and flame atomic absorption spectrometry (FAAS). The concentrations of metals in the water-soluble fraction (H{sub 2}O) decreased in the order Fe >Cu >Cr >Ni >Cd, and in the environmentally mobile fraction (CH{sub 3}COONH{sub 4}) in the order Cu >Fe >Ni >Cr >Cd. (orig.)

The immobilization of heavy metals in soil by bioaugmentation of a UV-mutant Bacillus subtilis 38 assisted by NovoGro biostimulation and changes of soil microbial community.

Science.gov (United States)

Wang, Ting; Sun, Hongwen; Mao, Hongjun; Zhang, Yanfeng; Wang, Cuiping; Zhang, Zhiyuan; Wang, Baolin; Sun, Lei

2014-08-15

Bacillus subtilis 38 (B38) is a mutant species of Bacillus subtilis acquired by UV irradiation with high cadmium tolerance. This study revealed that B38 was a good biosorbent for the adsorption of multiple heavy metals (cadmium, chromium, mercury, and lead). Simultaneous application of B38 and NovoGro (SNB) exhibited a synergetic effect on the immobilization of heavy metals in soil. The heavy metal concentrations in the edible part of the tested plants (lettuce, radish, and soybean) under SNB treatment decreased by 55.4-97.9% compared to the control. Three single extraction methods, diethylenetriaminepentaacetic acid (DTPA), Mehlich 3 (M3), and the first step of the Community Bureau of Reference method (BCR1), showed good predictive capacities for metal bioavailability to leafy, rhizome, and leguminous plant, respectively. The polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that NovoGro could enhance the proliferation of both exotic B38 and native microbes. Finally, the technology was checked in the field, the reduction in heavy metal concentrations in the edible part of radish was in the range between 30.8% and 96.0% after bioremediation by SNB treatment. This study provides a practical strategy for the remediation of farmland contaminated by multiple heavy metals. Copyright © 2014 Elsevier B.V. All rights reserved.

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)

The Effect of Applied Organic Fertilizers on the Bioavailability of Heavy Metals in Lolium Perenne, Cultivated on Fly Ash Deposits

Directory of Open Access Journals (Sweden)

Smaranda Mâşu

2011-10-01

Full Text Available The study aims to monitor the capacity of certain organic fertilizers (volcanic tuff and municipal sludge, applied as such and mixed with volcanic rocks with a high content in clinoptilolite, to determine the covering with vegetation of fly ash deposits resulted from the combustion of lignite in thermal plants. Both biosolids (20 t/ha and volcanic rock with high clinoptilolite content (5 t/ha determined the installation of a vegetative layer and diminished the soil metal bioavailability to the Lolium prerenne plant biomass. When using the organic-zeolite mixture, a synergistic effect is recorded of the two components of the treatment agent and an increase of the biomass with 448%. Moreover, the resulted biomass shows the highest reductions of metal bioaccumulations, of 38-46% for Zn and Fe, of 62% for Cu and between 82-89% for Cr, Ni and Pb.

Migration of heavy metals in soils in a uranium mining area

International Nuclear Information System (INIS)

Hu Ruixia; Gao Bai; Hu Baoqun; Feng Jiguang

2009-01-01

Contents of several heavy metals (Zn,Ni,Cu,Cd,Pb) in soil samples collected from different depths of the soil sections in a uranium mining area were analyzed, and vertical migration dis-ciplines of heavy metals were obtained. The results show that the concents of heavy metals in vertical direction decrease as the soil increases in thickness and there is a trend of facies-cumulation for the heavy metals. The accumulation status of each heavy metal in soils differs, which is dependent on the content and migration velocity of the heavy metal itself, the local natural environment about the soil, etc. (authors)

Heavy metal and abiotic stress inducible metallothionein isoforms from Prosopis juliflora (SW) D.C. show differences in binding to heavy metals in vitro.

Science.gov (United States)

Usha, B; Venkataraman, Gayatri; Parida, Ajay

2009-01-01

Prosopis juliflora is a tree species that grows well in heavy metal laden industrial sites and accumulates heavy metals. To understand the possible contribution of metallothioneins (MTs) in heavy metal accumulation in P. juliflora, we isolated and compared the metal binding ability of three different types of MTs (PjMT1-3). Glutathione S-transferase fusions of PjMTs (GSTMT1-3) were purified from Escherichia coli cells grown in the presence of 0.3 mM cadmium, copper or zinc. Analysis of metal bound fusion proteins using atomic absorption spectrometry showed that PjMT1 bound higher levels of all three heavy metals as compared to PjMT2 and PjMT3. A comparative analysis of the genomic regions (including promoter for all three PjMTs) is also presented. All three PjMTs are induced by H(2)O(2) and ABA applications. PjMT1 and PjMT2 are induced by copper and zinc respectively while PjMT3 is induced by copper, zinc and cadmium. Variation in induction of PjMTs in response to metal exposure and their differential binding to metals suggests that each MT has a specific role in P. juliflora. Of the three MTs analyzed, PjMT1 shows maximum heavy metal sequestration and is thus a potential candidate for use in heavy metal phytoremediation.

Heavy metal removal and recovery using microorganisms

Energy Technology Data Exchange (ETDEWEB)

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

1991-02-01

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

Heavy metal removal and recovery using microorganisms

International Nuclear Information System (INIS)

Wilde, E.W.; Benemann, J.R.

1991-02-01

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

Tracing heavy metals in 'swine manure - maggot - chicken' production chain.

Science.gov (United States)

Wang, Wanqiang; Zhang, Wenjuan; Wang, Xiaoping; Lei, Chaoliang; Tang, Rui; Zhang, Feng; Yang, Qizhi; Zhu, Fen

2017-08-21

With the development of large-scale livestock farming, manure pollution has drawn much attention. Conversion by insects is a rapid and cost-effective new method for manure management. Swine manure conversion with maggots (Musca domestica larvae) has developed, and the harvested maggots are often used as animal feed. However, the flow of heavy metals from manure to downstream processes cannot be ignored, and therefore, heavy metal content was measured in untreated raw manure, maggot-treated manure, harvested maggots and maggot-eating chickens (chest muscle and liver) to evaluate potential heavy metal risks. The levels of zinc, copper, chromium, selenium, cadmium and lead had significant differences between untreated raw manure and maggot-treated manure. The concentrations of all detected heavy metals, except for cadmium and selenium, in maggots met the limits established by the feed or feed additive standards of many countries. The bioaccumulation factor (BAF) of heavy metals decreased with the increase of the maggot instar, indicating that heavy metals were discharged from the bodies of maggots with the growth of maggots. Also, the contents of overall heavy metals in chickens fed harvested maggots met the standards for food. In conclusion, regarding heavy metals, it is eco-safe to use maggots in manure management.

Heavy Metals Accumulation Characteristics of Vegetables in Hangzhou City, China

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GU Yan-qing

2015-08-01

Full Text Available A field survey of heavy metal concentrations in soils and vegetables grown in 30 vegetable farmlands of Hangzhou City were carried out. Through calculating the bioconcentration factor(BCFand transfer factor(TFfor different heavy metals(Cu, Zn, Cd, Cr and Pbin 27 kinds of different vegetables which belong to leafy vegetables, root vegetables or eggplant fruit vegetables, assessing their accumulation characteristics of heavy metals according to the differences of the bio-concentration factor, the reasonable proposals were put forward to optimize the planting structure of vegetables in mild and middle-level heavy metal contamination soils. The experimental results were as follows: In soils with mild and middle-level heavy metal contamination, leafy vegetables, such as crown daisy, cabbage, celery and Chinese long cabbage, had relatively low enrichment ability of heavy metals, so as the root and fruit vegetables like white radish, carrot, tomatoes, hence these vegetables could be planted preferentially. In contrast, some kinds of vegetables, including white amaranth, red amaranth, tatsoi, broccoli, gynura, brassica juncea and lettuce of leafy vegetables, lactuca sativa, taro, red radish and cherry radish of rhizome vegetables and sweet pepper of fruit vegetables, had relatively high accumulation ability of heavy metal, which should be avoided to be planted in soils with mild and middle-level heavy metal contamination.

Novel polymer-based nanocomposites for application in heavy metal pollution remediation

CSIR Research Space (South Africa)

Kotzé-Jacobs, L

2012-10-10

Full Text Available and kidney damage and also cancer ? Heavy metals can accumulate in food sources through heavy metal contamination of soil and plants ? CSIR 2012 Slide 3 Removal of heavy metals ? Small volume applications: ion exchange ? Larger volumes eg. acid mine... pollution, treatment shortfalls at municipalities and contaminated surface water discharges ? Accumulation of heavy metals and endocrine disrupters ? CSIR 2012 Slide 2 Introduction: Heavy metals ? Cr, Ni, Cu, Pb, As etc. ? Exposure can cause liver...

Heavy metal displacement in chelate-irrigated soil during phytoremediation

Science.gov (United States)

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

2003-03-01

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

Metabolic Demands of Heavy Metal Drumming

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Bryan Romero

2016-07-01

Full Text Available Background: The drum set involves dynamic movement of all four limbs. Motor control studies have been done on drum set playing, yet not much is known about the physiological responses to this activity. Even less is known about heavy metal drumming. Aims: The purpose of this study was to determine metabolic responses and demands of heavy metal drumming. Methods: Five semi-professional male drummers (mean ± SD age = 27.4 ± 2.6 y, height = 177.2 ± 3.8 cm, body mass = 85.1 ± 17.8 kg performed four prescribed and four self-selected heavy metal songs. Oxygen consumption (VO2, minute ventilation (VE and respiratory exchange ratio (RER were measured using a metabolic cart.  Heart rate (HR was measured using a heart rate monitor. VO2max was determined using a graded cycle ergometer test. Results: The results indicated a metabolic cost of 6.3 ± 1.4 METs and heart rate of 145.1 ± 15.7 beats·min-1 (75.4 ± 8.3% of age-predicted HRmax. VO2 peak values reached approximately 90% of the drummer’s VO2max when performing at the fastest speeds. According to these results, heavy metal drumming may be considered vigorous intensity activity (≥ 6.0 METs. The relative VO2max of 40.2 ± 9.5 mL·kg·min-1 leads to an aerobic fitness classification of “average” for adult males. Conclusions: The metabolic demands required during heavy metal drumming meet the American College of Sports Medicine guidelines for the development of health related fitness.  Keywords: Drum set, Exercise physiology, VO2, Music

[Resistance to heavy metals in ruminal staphylococci].

Science.gov (United States)

Lauková, A

1994-01-01

Ruminal, coagulase-negative, urease and bacteriocin-like substances producing staphylococci were screened for their heavy metal ions and antibiotics resistance. All strains tested were resistant to disodium arsenate at a minimal inhibition concentration (MIC > 5 g/l) and cadmium sulphate (MIC > 4 g/l). MIC = 50-60 mg/l was determined in eight staphylococci screened in mercury chloride resistance test (Tab. I). Silver nitrate resistance was detected in seven of the bacteria used (MIC = 40-50 mg/l). All strains were novobiocin resistant. Staphylococcus cohnii subsp. urealyticum SCU 40 was found as a strain with resistance to all heavy metal ions and 5 antibiotics (Tab. II). In addition, this strain produced bacteriocin-like substance which inhibited growth of six indicators of different origin (Tab. II). The most of staphylococci were detected as heavy metal ion polyresistant strains and antibiotic polyresistant strains producing antimicrobial substances with inhibition effects against at least one indicator of different origin. These results represent the first information on heavy metal ion resistance in ruminal bacteria. They also show relation or coresistance between heavy metal ions and antibiotics. Resulting from this study, staphylococci can be used as a bioindicator model for animal environmental studies. In addition, it can be used for specific interactions studies within the framework of ruminal bacterial ecosystem and also mainly with regard to molecular genetic studies.

Experimental testing facilities for ultrasonic measurements in heavy liquid metal

International Nuclear Information System (INIS)

Cojocaru, V.; Ionescu, V.; Nicolescu, D.; Nitu, A.

2016-01-01

The thermo-physical properties of Heavy Liquid Metals (HLM), like lead or its alloy, Lead Bismuth Eutectic (LBE), makes them attractive as coolant candidates in advanced nuclear systems. The opaqueness, that is common to all liquid metals, disables all optical methods. For this reason ultrasound waves are used in different applications in heavy liquid metal technology, for example for flow and velocity measurements and for inspection techniques. The practical use of ultrasound in heavy liquid metals still needs to be demonstrated by experiments. This goal requires heavy liquid metal technology facility especially adapted to this task. In this paper is presented an experimental testing facility for investigations of Heavy Liquid Metals acoustic properties, designed and constructed in RATEN ICN. (authors)

Heavy metals in trees and energy crops - a literature review

International Nuclear Information System (INIS)

Johnsson, Lars

1995-12-01

This literature review deals with the use of energy crops for cleaning of soils from heavy metals. It also deals with the use of low accumulating energy crops to be used on strongly contaminated soils where a low uptake of heavy metals is preferred, for example on mining deposits. In addition to the efforts to reduce the sources for heavy metal contamination of soils (for example commercial fertilizers and atmospheric deposition) the uptake and removal of heavy metals from the soils by the use of energy crops have recently been discussed as a method for cleaning of soils. Species from the Salix family (willow) have a greater potential for accumulating heavy metals than cereals which makes them interesting for this purpose. The Salix family consists of species with a great genetic variation. This will probably make it possible to find or develop clones with different characteristics suitable for cleaning of contaminated soils as well as for plant covering of soils that are extremely contaminated by heavy metals. In the former case an accumulation of heavy metals in the harvested parts, the shoots, is preferred. In the later case clones that do not accumulate heavy metals and maybe also clones with only root accumulation are preferred. There are also Salix clones with a specific accumulation of heavy metals which makes it possible to clean soils from a toxic metal and at the same time avoid the risk for deficiency of essential metals, for example Zn. The greatest potential to clean soils by the use of energy crops, is when the contamination levels in the soils are low, the areas to clean are large and when the time needed for cleaning is of minor importance. The most suitable soils are those where the metal contamination is located in the top soil layer and where the heavy metal concentrations in the sub soil layer are still low. 58 refs, 8 tabs, 1 fig

distribution pattern of some he funtua textile li ttern of some heavy ...

African Journals Online (AJOL)

user pc

2017-12-02

Dec 2, 2017 ... ic Absorption Spectrometry, Funtua textile, Heavy metals, Particulate any materials .... was potentially highly bioavailable for plant uptake (Uba et al., 2008 ..... Y.A Dalltu approved the design and supervised the experiment.

Microbes in Heavy Metal Remediation: A Review on Current Trends and Patents.

Science.gov (United States)

Mishra, Geetesh Kumar

2017-01-01

Heavy metal pollution in the environmental samples like soil, water and runoff water is a worldwide problem. Such contamination of environmental matrices by the heavy metals accumulates due to various activities involving human driven sources and industries, although agriculture and sewage disposal are the largest source for the heavy metal contamination. Disposal of heavy metals or waste products containing heavy metals in the environment postures a trivial threat to public safety and health. Heavy metals are persistence and they can also cause biomagnifications and accumulate in food chain. Microbial bioremediation of heavy metal is emerging as an effective technique. Microbial bioremediation is a highly efficient environmental friendly procedure which also reduces the cost of cleanup process associated with heavy metal contamination. New methods for removal of heavy metals from the environmental samples are under development and most recent advancements have been made in exploring the knowledge of metal-microbes interactions and its use for heavy metal remediation. This review paper will focus on the microbial bioremediation process and highlight some of the newly developed patented methods for microbial bioremediation of the heavy metals from the environmental samples using microbial populations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Heavy metal contamination status and source apportionment in sediments of Songhua River Harbin region, Northeast China.

Science.gov (United States)

Li, Ning; Tian, Yu; Zhang, Jun; Zuo, Wei; Zhan, Wei; Zhang, Jian

2017-02-01

The Songhua River represents one of the seven major river systems in China. It flows through Harbin city with 66 km long, locating in the northern China with a longer winter time. This paper aimed to study concentration distributions, stability, risk assessment, and source apportionment of heavy metals including chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), and nickel (Ni) in 11 selected sections of the Songhua River Harbin region. Results showed that Cr, Cd, Pb, Hg, and As exceeded their respective geochemical background values in sediments of most monitoring sections. Compared with other important rivers and lakes in China, Cr, Hg, Cd, and As pollutions in surface sediments were above medium level. Further analysis of chemical speciation indicated that Cr and As in surface sediments were relatively stable while Pb and Cd were easily bioavailable. Correlation analysis revealed sources of these metals except As might be identical. Pollution levels and ecological risks of heavy metals in surface sediments presented higher in the mainstream region (45° 47.0' N ~ 45° 53.3' N, 126° 37.0' E ~ 126° 42.1' E). Source apportionment found Hejiagou and Ashi River were the main contributors to metal pollution of this region. Thus, anthropogenic activities along the Hejiagou and Ashi River should be restricted in order to protect the Songhua River Harbin region from metal contamination.

Atmospheric heavy metal deposition in Europe estimated by moss analysis

Energy Technology Data Exchange (ETDEWEB)

Ruehling, Aa. [Swedish Environmental Research Inst., Lund (Sweden). Dept. of Ecology

1995-12-31

Atmospheric heavy metal deposition in Europe including 21 countries was monitored in 1990-1992 by the moss technique. This technique is based on the fact that the concentrations of heavy metals in moss are closely correlated to atmospheric deposition. This was the first attempt to map heavy metal deposition in this large area. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicate the location of important heavy metal pollution sources and to allow retrospective comparisons with similar studies. The present survey is a follow-up of a joint Danish and Swedish project in 1980 and an extended survey in 1985 within the framework of the Nordic Council of Ministers. In Sweden, heavy-metal deposition was first mapped on a nation-wide scale in 1968-1971 and 1975. (author)

Atmospheric heavy metal deposition in Europe estimated by moss analysis

Energy Technology Data Exchange (ETDEWEB)

Ruehling, Aa [Swedish Environmental Research Inst., Lund (Sweden). Dept. of Ecology

1996-12-31

Atmospheric heavy metal deposition in Europe including 21 countries was monitored in 1990-1992 by the moss technique. This technique is based on the fact that the concentrations of heavy metals in moss are closely correlated to atmospheric deposition. This was the first attempt to map heavy metal deposition in this large area. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicate the location of important heavy metal pollution sources and to allow retrospective comparisons with similar studies. The present survey is a follow-up of a joint Danish and Swedish project in 1980 and an extended survey in 1985 within the framework of the Nordic Council of Ministers. In Sweden, heavy-metal deposition was first mapped on a nation-wide scale in 1968-1971 and 1975. (author)

Oral bioavailability of heavy metals and organic compounds from soil ; too complicated to absorb? An inventarisation of factors affecting bioavailability of environmental contaminants from soil

NARCIS (Netherlands)

Sips AJAM; Eijkeren JCH van; LBO

1996-01-01

Bioavailability plays an important role in risk assessment of environmental contaminants from soil. It is one of the determinants in the assessment of intervention values. In present risk assessment, bioavailability from soil is supposed to be 100% due to a paucity of reliable information. However,

Heavy metals' data in soils for agricultural activities

Directory of Open Access Journals (Sweden)

T.A. Adagunodo

2018-06-01

Full Text Available In this article, the heavy metals in soils for agricultural activities were analyzed statistically. Ten (10 soil samples were randomly taken across the agricultural zones in Odo-Oba, southwestern Nigeria. Ten (10 metals; namely: copper (Cu, lead (Pb, chromium (Cr, arsenic (As, zinc (Zn, cadmium (Cd, nickel (Ni, antimony (Sb, cobalt (Co and vanadium (V were determined and compared with the guideline values. When the values were compared with the international standard, none of the heavy metals in the study area exceeded the threshold limit. However, the maximum range of the samples showed that Cr and V exceeded the permissible limit which could be associated with ecological risk. The data can reveal the distributions of heavy metals in the agricultural topsoil of Odo-Oba, and can be used to estimate the risks associated with the consumption of crops grown on such soils. Keywords: Agricultural soils, Heavy metals, Contamination, Environment, Soil screening, Geostatistics

Translocation of metals in pea plants grown on various amendment of electroplating industrial sludge.

Science.gov (United States)

Bose, Sutapa; Chandrayan, Sudarshana; Rai, Vivek; Bhattacharyya, A K; Ramanathan, A L

2008-07-01

A pot-culture experiment was conducted to observe the effects of acidic sludge addition to the soils on bioavailability and uptake of heavy metals in different parts of pea plant as well as its influence on the growth of that plant. It is observed from our result the abundances of total and bio-available heavy metals in sludge vary as follows: Fe>Mn>Cr>Ni>Cu>Pb>Zn>Cd and Fe>Ni>Mn>Cr>Cu>Zn>Pb>Cd. Sludge applications increased both the total metals, DTPA-extractable metals and total N in the soils. On the other hand lime application has decreased the bioavailability of heavy metals with no change in total N in sludge amended soils. Organic carbon showed positive correlation with all metals except Zn, Cr and Pb. CEC also showed a strong positive correlation (R(2)>0.7) with the low translocation efficiency of pea plants. The value of translocation factor from shoot to seed was found to be smaller than root to shoot of pea plants. Our study thus shows that pea plants were found to be well adapted to the soil amended with 10% sludge with 0.5% lime treatment, minimizing most of the all metal uptake in the shoot of that plant. So, on the basis of the present study, possible treatment may be recommended for the secure disposal of acidic electroplating sludge.

[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.

Biosorption of heavy metals and uranium from dilute solutions

International Nuclear Information System (INIS)

Schneider, I.A.H.; Misra, M.; Smith, R.W.

1995-01-01

Eichhornia crassipes approaches being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time it is known to readily abstract heavy metal ions from water and, thus, aids in the removal of heavy metals found in such waters. This paper considers the possibility of using specific parts of the plant as an inexpensive adsorbent for the removal of heavy metals from contaminated chemical and mining industry waste waters. In particular the root of the plant was found to be an excellent accumulator of heavy metal ions including uranium from solution. It is also suggested that dried roots of the plant might be placed in simple bags and used in a very low cost metal ion removal system

Proceedings of 15th International Conference on Heavy Metals in the Environment

International Nuclear Information System (INIS)

Barganska, Z.; Beyer, A; Klimaszewska, K.; Namiesnik, J.; Tobiszewski, M.; Rutkiewicz, I.

2010-01-01

15 th International Conference on Heavy Metals in the Environment (15 th ICHMET) is a continuation of a series of conferences that have been held since 1975. These conferences typically draw 500-1000 participants from countries in many parts of the world. The ICHMETs are the only forum that provide an integrated perspective on research and policy initiatives on all heavy metals in a trans-disciplinary context. There is a need to understand not only the unique features and behavior of individual heavy metals but also the differences, similarities and interactions of different metals at the ecosystem, systemic and cellular levels if we are to deal with the problems of global heavy metal pollution in a sustainable manner. The presented contributions concerned problems: (1) trend tracking/analysis of heavy metals data; (2) analytical tools and techniques; (3) heavy metals in the marine environment; (4) accumulation in foods and crops; (5) soil contamination; (6) heavy metals in sediments and remediation technologies; (7) effects on human health; (8) heavy metals in the atmosphere; (9) sources, emissions and control of heavy metals; (10) phytoremediation; (11) wastewater treatment; (12) heavy metals in the historical pollution record.

ASSESSMENT OF HEAVY METALS AND CRUDE PROTEIN ...

African Journals Online (AJOL)

UNICORN

to quantify heavy metals (Cu, Zn, Pb and Cd) and crude protein content of these species that are sold in ... in protein, omega 3 and low fat content. Furthermore ... high levels of cadmium can cause kidney and liver damage in man [6]. Motivation .... analysis. Determination of heavy metals in the edible tissues of the organisms.

THE HEAVY METALS CONNTENT IN VEGETABLES FROM MIDDLE SPIŠ AREA

Directory of Open Access Journals (Sweden)

Marek Slávik,Tomáš Tóth

2014-02-01

Full Text Available In the middle area of Spiš, it is significantly burden by heavy metals what is documented by radical content of Hg in soil from Rudňany 58.583645 mg.kg -1. On the content of heavy metals in vegetables grown in this soil it has the same effect. 61.5% samples exceeded the limit value of heavy metals. The most dangerous vegetables were Lactuca sativa L. The limit value was exceed in all determine heavy metals - Hg, Cd, Pb and Cu in this vegetables. In the case of Hg, the limit value exceed 93.86 times. For relatively safety is growing of Pisum sativum L., where there was no exceed any limits values. The root vegetables are dangerous, where the sample of Raphanus sativus L. exceed 6.71978 times the limit values for Pb although the content of lead in the soil was under hygienic limits. Transfer of heavy metals into consume parts of vegetables was no limited by high content of humus into soil. Transfer of heavy metals into consume parts of vegetables was no limited by weakly alkaline soil reaction. These factors are considered for factors limited mobility and input heavy metals into plants. We determined heavy metals by AAS method on a Varian 240 FS and method AMA 254.

Magnetic evidence for heavy metal pollution of topsoil in Shanghai, China

Science.gov (United States)

Wang, Guan; Liu, Yuan; Chen, Jiao; Ren, Feifan; Chen, Yuying; Ye, Fangzhou; Zhang, Weiguo

2018-03-01

This study presents the results obtained from magnetic susceptibility and heavy metal (Cu, Zn, Pb, and Cr) concentration measurements of soil profiles collected from arable land and urban parks in Baoshan District, an industrial district of Shanghai, China. The study focuses on the investigation of vertical variations in magnetic susceptibilities and heavy metal concentrations and on correlations between magnetic susceptibilities and heavy metal concentrations in soil profiles. The results demonstrate that magnetic enhancement in the surface layer of the soil profile is associated with increased heavy metal pollution. The enrichment factors (EF) and the Tomlinson Pollution Load Index (PLI-EF) are calculated for estimating the level of heavy metal pollution of soil profiles in the study. The significant positive correlations between heavy metal contents, enrichment factors (EF), Tomlinson pollution load index (PLI-CF), modified Tomlinson pollution load index (PLI-EF), and magnetic susceptibility (c) indicate that much of the heavy metal contamination in the study area is linked to combustion derived particulate emissions. The results confirm that the combined magnetic measurement and heavy metal concentration analysis could provide useful information for soil monitoring in urban environments. However, the use of magnetic technique to locate the heavy metal pollution boundary in the soil profile of this studied area should be confirmed by further geochemical analysis.