WorldWideScience

Sample records for metal-contaminated subsurface soils

  1. Aromatic plant production on metal contaminated soils

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  2. Aromatic plant production on metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-01

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

  3. Heavy metal contamination of soil and sediment in Zambia

    African Journals Online (AJOL)

    USER

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

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

    Indian Academy of Sciences (India)

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

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

    African Journals Online (AJOL)

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

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

    International Nuclear Information System (INIS)

    Hansen, J.E.

    1991-01-01

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

  7. Electrokinetic In Situ Treatment of Metal-Contaminated Soil

    Science.gov (United States)

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

    2004-01-01

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

  8. Heavy metal movement in metal-contaminated soil profiles

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  9. Soil microbial effects of smelter induced heavy metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Nordgren, A

    1986-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

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

  11. Functioning of metal contaminated garden soil after remediation

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  12. Air separation of heavy metal contaminants from soil

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-01

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

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

    Science.gov (United States)

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

    2010-02-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  16. 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.

  17. Eco-toxicity and metal contamination of paddy soil in an e-wastes recycling area

    International Nuclear Information System (INIS)

    Zhang Junhui; Hang Min

    2009-01-01

    Paddy soil samples taken from different sites in an old primitive electronic-waste (e-waste) processing region were examined for eco-toxicity and metal contamination. Using the environmental quality standard for soils (China, Grade II) as reference, soil samples of two sites were weakly contaminated with trace metal, but site G was heavily contaminated with Cd (6.37 mg kg -1 ), and weakly contaminated with Cu (256.36 mg kg -1 ) and Zn (209.85 mg kg -1 ). Zn appeared to be strongly bound in the residual fraction (72.24-77.86%), no matter the soil was metal contaminated or not. However, more than 9% Cd and 16% Cu was present in the non-residual fraction in the metal contaminated soils than in the uncontaminated soil, especially for site G and site F. Compared with that of the control soil, the micronucleus rates of site G and site F soil treatments increased by 2.7-fold and 1.7-fold, respectively. Low germination rates were observed in site C (50%) and site G (50%) soil extraction treated rice seeds. The shortest root length (0.2377 cm) was observed in site G soil treated groups, which is only 37.57% of that of the control soil treated groups. All of the micronucleus ratio of Vicia faba root cells, rice germination rate and root length after treatment of soil extraction indicate the eco-toxicity in site F and G soils although the three indexes are different in sensitivity to soil metal contamination.

  18. Stabilization and solidification of a heavy metal contaminated site soil using a hydroxyapatite based binder

    OpenAIRE

    Xia, Wei-Yi; Feng, Ya-Song; Jin, Fei; Zhang, Li-Ming; Du, Yan-Jun

    2017-01-01

    Synthetic hydroxyapatite (HA) is an efficient and environment-friendly material for the remediation of heavy metal contaminated soils. However, the application of conventional HA powder in stabilizing contaminated soils is limited, due to high cost of final products, difficulties in synthesizing purified HA crystals. A new binder named SPC, which composes of single superphosphate (SSP) and calcium oxide (CaO), is presented as an alternative in this study. HA can form in the soil matrix by an ...

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  1. Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities

    International Nuclear Information System (INIS)

    Cang Long; Zhou Dongmei; Wang Quanying; Wu Danya

    2009-01-01

    There is a growing concern on the potential application of a direct current (DC) electric field to soil for removing contaminants, but little is known about its impact on soil enzyme activities. This study investigated the change of enzyme activities of a heavy metal contaminated soil before and after electrokinetic (EK) treatments at lab-scale and the mechanisms of EK treatment to affect soil enzyme activities were explored. After treatments with 1-3 V cm -1 of voltage gradient for 420 h, soil pH, electrical conductivity (EC), soil organic carbon, dissolved organic carbon (DOC), soil heavy metal concentration and enzyme activities were analyzed. The results showed that the average removal efficiencies of soil copper were about 65% and 83% without and with pH control of catholyte, respectively, and all the removal efficiencies of cadmium were above 90%. The soil invertase and catalase activities increased and the highest invertase activity was as 170 times as the initial one. The activities of soil urease and acidic phosphatase were lower than the initial ones. Bivariate correlation analyses indicated that the soil invertase and acidic phosphatase activities were significantly correlated with soil pH, EC, and DOC at P < 0.05, but the soil urease activities had no correlation with the soil properties. On the other hand, the effects of DC electric current on solution invertase and catalase enzyme protein activities indicated that it had negative effect on solution catalase activity and little effect on solution invertase activity. From the change of invertase and catalase activities in soil and solution, the conclusion can be drawn that the dominant effect mechanism is the change of soil properties by EK treatments.

  2. Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities

    Energy Technology Data Exchange (ETDEWEB)

    Cang Long [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhou Dongmei, E-mail: dmzhou@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Wang Quanying; Wu Danya [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China)

    2009-12-30

    There is a growing concern on the potential application of a direct current (DC) electric field to soil for removing contaminants, but little is known about its impact on soil enzyme activities. This study investigated the change of enzyme activities of a heavy metal contaminated soil before and after electrokinetic (EK) treatments at lab-scale and the mechanisms of EK treatment to affect soil enzyme activities were explored. After treatments with 1-3 V cm{sup -1} of voltage gradient for 420 h, soil pH, electrical conductivity (EC), soil organic carbon, dissolved organic carbon (DOC), soil heavy metal concentration and enzyme activities were analyzed. The results showed that the average removal efficiencies of soil copper were about 65% and 83% without and with pH control of catholyte, respectively, and all the removal efficiencies of cadmium were above 90%. The soil invertase and catalase activities increased and the highest invertase activity was as 170 times as the initial one. The activities of soil urease and acidic phosphatase were lower than the initial ones. Bivariate correlation analyses indicated that the soil invertase and acidic phosphatase activities were significantly correlated with soil pH, EC, and DOC at P < 0.05, but the soil urease activities had no correlation with the soil properties. On the other hand, the effects of DC electric current on solution invertase and catalase enzyme protein activities indicated that it had negative effect on solution catalase activity and little effect on solution invertase activity. From the change of invertase and catalase activities in soil and solution, the conclusion can be drawn that the dominant effect mechanism is the change of soil properties by EK treatments.

  3. 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.

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

    Science.gov (United States)

    Lovley, Derek R.; Anderson, Robert T.

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

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

    Science.gov (United States)

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

    2017-09-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    African Journals Online (AJOL)

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

  8. MINE WASTE TECHNOLOGY PROGRAM; PHOSPHATE STABILIZATION OF HEAVY METALS CONTAMINATED MINE WASTE YARD SOILS, JOPLIN, MISSOURI NPL SITE

    Science.gov (United States)

    This document summarizes the results of Mine Waste Technology Project 22-Phosphate Stabilization of Heavy Metals-Contaminated Mine Waste Yard Soils. Mining, milling, and smelting of ores near Joplin, Missouri, have resulted in heavy metal contamination of the area. The Joplin s...

  9. 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.

  10. Toxic heavy metal contamination assessment and speciation in sugarcane soil

    Science.gov (United States)

    Wang, Xiaofei; Deng, Chaobing; Yin, Juan; Tang, Xiang

    2018-01-01

    The increasing heavy metal pollution in the sugarcane soils along the Great Huanjiang River was caused by leakage and spills of Lead (Pb) and Zinc (Zn) tailing dams during a flood event. Copper (Cu), Zn, Pb, Cadmium (Cd), and Arsenic (As) concentrations of soil samples collected from 16 different sites along the Great Huanjiang River coast typical pollution area were analyzed by Inductive Coupled Plasma Mass Spectrometry (ICP-MS). The mean concentrations of Pb, Cd, Zn, Cu, and As in the sugarcane soils were 151.57 mg/kg, 0.33 mg/kg, 155.52 mg/kg, 14.19 mg/kg, and 18.74 mg/kg, respectively. Results from the analysis of heavy metal speciation distribution showed that Cu, Zn, Pb, and Cd existed in weak acid, reducible, and oxidizable fractions, and the sum of these fractions accounted for significant proportions in sugarcane soils. However, the residual fraction of As with high proportion of reducible fraction indicated that this trace element still poses some environmental risk in the sugarcane soils because of its high content. Assessments of pollution levels revealed that the highest environmental risk was arouse by Pb. In addition, moderate to strong Cd and Zn pollution were found, while As has zero to medium level of pollution and Cu has zero level.

  11. Proximal spectral sensing to monitor phytoremediation of metal - contaminated soils

    NARCIS (Netherlands)

    Rathod, P.H.; Rossiter, D.; Noomen, M.; van der Meer, F.D.

    2013-01-01

    Assessment of soil contamination and its long-term monitoring are necessary to evaluate the effectiveness of phytoremediation systems. Spectral sensing-based monitoring methods promise obvious benefits compared to field-based methods: lower cost, faster data acquisition and better spatio-temporal

  12. Heavy Metal Contamination of Soils and Vegetation around Solid ...

    African Journals Online (AJOL)

    MICHAEL

    1.61ppm respectively at the East – West road dumpsite and 2.42 ± 1.87ppm, 1.40 ± 0.61ppm, 1.39 ± 0.67ppm ... The differences in the levels of copper, zinc and lead in soils and ... waste management (Ademola, 1993: Osibanjo, 1995;.

  13. In-Situ Electrokinetic Remediation for Metal Contaminated Soils

    Science.gov (United States)

    2001-03-01

    phytoremediation , and electrokinetic extraction. The US Army Environmental Center (USAEC) and Engineer Research and Development Center (ERDC...California (CA) List Metals: Antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury , molybdenum, nickel, selenium...Comparison Technologies with which electrokinetic remediation must compete are "Dig and Haul", Soil Washing, and Phytoremediation . "Dig and haul

  14. Metal contamination of agricultural soils in the copper mining areas ...

    Indian Academy of Sciences (India)

    Soma Giri

    2017-06-07

    Jun 7, 2017 ... Agricultural soil; heavy metals; copper mining areas; multivariate analysis; ... multivariate statistical analysis. 2. ... sieved through standard sieve of 200 mesh size (Giri ... Pearson's correlation is a bivariate correlation ... is a variation reduction technique in which a num- ... Varimax rotation is applied to all the.

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

    African Journals Online (AJOL)

    Manihot esculentum is a major farm produce in southern .... Heavy metals enrichment factor was derived based ... VII. 0-15. 6.1. 2.3. 58.41. 15-30. 6.3. 1.8. 54.28. VIII. 0-15. 6.5. 2.5. 62.21 ... levels of iron in soils around foam manufacturing, ...

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

    African Journals Online (AJOL)

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

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

    Directory of Open Access Journals (Sweden)

    Chao Su

    2014-06-01

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

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

    African Journals Online (AJOL)

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

  19. Recent advances in conventional and contemporary methods for remediation of heavy metal-contaminated soils.

    Science.gov (United States)

    Sharma, Swati; Tiwari, Sakshi; Hasan, Abshar; Saxena, Varun; Pandey, Lalit M

    2018-04-01

    Remediation of heavy metal-contaminated soils has been drawing our attention toward it for quite some time now and a need for developing new methods toward reclamation has come up as the need of the hour. Conventional methods of heavy metal-contaminated soil remediation have been in use for decades and have shown great results, but they have their own setbacks. The chemical and physical techniques when used singularly generally generate by-products (toxic sludge or pollutants) and are not cost-effective, while the biological process is very slow and time-consuming. Hence to overcome them, an amalgamation of two or more techniques is being used. In view of the facts, new methods of biosorption, nanoremediation as well as microbial fuel cell techniques have been developed, which utilize the metabolic activities of microorganisms for bioremediation purpose. These are cost-effective and efficient methods of remediation, which are now becoming an integral part of all environmental and bioresource technology. In this contribution, we have highlighted various augmentations in physical, chemical, and biological methods for the remediation of heavy metal-contaminated soils, weighing up their pros and cons. Further, we have discussed the amalgamation of the above techniques such as physiochemical and physiobiological methods with recent literature for the removal of heavy metals from the contaminated soils. These combinations have showed synergetic effects with a many fold increase in removal efficiency of heavy metals along with economic feasibility.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

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

    International Nuclear Information System (INIS)

    Lestan, Domen; Luo Chunling; Li Xiangdong

    2008-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Miroslav Štofko

    2006-06-01

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

  3. Use of Hydrophilic Insoluble Polymers in the Restoration of Metal-Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Guiwei Qu

    2009-01-01

    Full Text Available To develop cost-effective techniques that contribute to phytostabilization of severely metal-contaminated soils is a necessary task in environmental research. Hydrophilic insoluble polymers have been used for some time in diapers and other hygienic products and to increase the water-holding capacity of coarse-textured soils. These polymers contain groups, such as carboxyl groups, that are capable of forming bonds with metallic cations, thereby decreasing their bioavailability in soils. The use of polyacrylate polymers as soil amendments to restore metal-contaminated soils has been investigated in the Technical University of Lisbon since the late nineties. Plant growth and plant nutrients concentrations, extractable levels of metals in soil, and soil enzyme activities were used to monitor the improvement in soil quality following the application of these polymers. In contaminated soils, hydrophilic insoluble polymers can create microcosms that are rich in water and nutrients (counterions but only contain small concentrations of toxic elements; the conditions of these microenvironments are favorable to roots and microorganisms. In this paper we described the most relevant information available about this topic.

  4. Use of Hydrophilic Insoluble Polymers in the Restoration of Metal-Contaminated Soils

    International Nuclear Information System (INIS)

    Qu, G.; De Varennes, A.; Qu, G.

    2010-01-01

    To develop cost-effective techniques that contribute to phyto stabilization of severely metal-contaminated soils is a necessary task in environmental research. Hydrophilic insoluble polymers have been used for some time in diapers and other hygienic products and to increase the water-holding capacity of coarse-textured soils. These polymers contain groups, such as carboxyl groups, that are capable of forming bonds with metallic cations, thereby decreasing their bioavailability in soils. The use of polyacrylate polymers as soil amendments to restore metal-contaminated soils has been investigated in the Technical University of Lisbon since the late nineties. Plant growth and plant nutrients concentrations, extractable levels of metals in soil, and soil enzyme activities were used to monitor the improvement in soil quality following the application of these polymers. In contaminated soils, hydrophilic insoluble polymers can create microcosms that are rich in water and nutrients (counterions) but only contain small concentrations of toxic elements; the conditions of these micro environments are favorable to roots and microorganisms. In this paper we described the most relevant information available about this topic.

  5. Response of soil microbial communities and microbial interactions to long-term heavy metal contamination.

    Science.gov (United States)

    Li, Xiaoqi; Meng, Delong; Li, Juan; Yin, Huaqun; Liu, Hongwei; Liu, Xueduan; Cheng, Cheng; Xiao, Yunhua; Liu, Zhenghua; Yan, Mingli

    2017-12-01

    Due to the persistence of metals in the ecosystem and their threat to all living organisms, effects of heavy metal on soil microbial communities were widely studied. However, little was known about the interactions among microorganisms in heavy metal-contaminated soils. In the present study, microbial communities in Non (CON), moderately (CL) and severely (CH) contaminated soils were investigated through high-throughput Illumina sequencing of 16s rRNA gene amplicons, and networks were constructed to show the interactions among microbes. Results showed that the microbial community composition was significantly, while the microbial diversity was not significantly affected by heavy metal contamination. Bacteria showed various response to heavy metals. Bacteria that positively correlated with Cd, e.g. Acidobacteria_Gp and Proteobacteria_thiobacillus, had more links between nodes and more positive interactions among microbes in CL- and CH-networks, while bacteria that negatively correlated with Cd, e.g. Longilinea, Gp2 and Gp4 had fewer network links and more negative interactions in CL and CH-networks. Unlike bacteria, members of the archaeal domain, i.e. phyla Crenarchaeota and Euryarchaeota, class Thermoprotei and order Thermoplasmatales showed only positive correlation with Cd and had more network interactions in CH-networks. The present study indicated that (i) the microbial community composition, as well as network interactions was shift to strengthen adaptability of microorganisms to heavy metal contamination, (ii) archaea were resistant to heavy metal contamination and may contribute to the adaption to heavy metals. It was proposed that the contribution might be achieved either by improving environment conditions or by cooperative interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Remediation of a heavy metal-contaminated soil by means of agglomeration.

    Science.gov (United States)

    Polettini, Alessandra; Pomi, Raffaella; Valente, Mattia

    2004-01-01

    The feasibility of treating a heavy metal-contaminated soil by means of a solidification/stabilization treatment consisting of a granulation process is discussed in the present article. The aim of the study was to attain contaminant immobilization within the agglomerated solid matrix. The soil under concern was characterized by varying levels of heavy metal contamination, ranging from 50 to 500 mg kg(-1) dry soil for chromium. from 300 to 2000 mg kg(-1) dry soil for lead and from 270 to 5000 mg kg(-1) dry soil for copper. An artificially contaminated soil with contaminant concentrations corresponding to the upper level of the mentioned ranges was prepared from a sample of uncontaminated soil by means of spiking experiments. Pure soluble species of chromium, copper and lead. namely CrCl3.6H2O, CuCl2.2H2O and Pb(NO3)2, were selected for the spiking experiments, which were arranged according to a 2(3) full factorial design. The solidification/stabilization treatment was based on an agglomeration process making use of hydraulic binders including Portland cement, hydrated lime and sodium methasilicate, which were selected on the basis of preliminary test runs. It was found that after 7 days of curing the applied treatment was able to efficiently immobilize the investigated heavy metals within the hydrated matrix. Good acid neutralization behavior was also observed, indicating improved matrix resistance to acid attack and decreased potential for metal leaching.

  7. INVESTIGATION OF HEAVY METAL CONTAMINATION IN THE ROADSIDE SOIL AT MORENA DISTRICT IN INDIA

    OpenAIRE

    Laxmi Kant Sharma

    2016-01-01

    Pollution of natural environment due to release of heavy metals from various sources is a widespread problem throughout the world. This study explains the effect of heavy metal contaminants in Roadside soil of Morena district. Twelve air dried surface soil samples were collected from 50cm – 1m (point A) and twelve from 30m (point B) away from the roadside along a road with a distance of 50 km. Heavy metals were found in both points with highest concentration at 50cm – 1m (point A). Roadside s...

  8. Effect of biosludge and biofertilizer amendment on growth of Jatropha curcas in heavy metal contaminated soils.

    Science.gov (United States)

    Juwarkar, Asha Ashok; Yadav, Santosh Kumar; Kumar, Phani; Singh, Sanjeev Kumar

    2008-10-01

    The pot experiments were conducted to evaluate the effect of different concentrations of arsenic, chromium and zinc contaminated soils, amended with biosludge and biofertilizer on the growth of Jatropha curcas which is a biodiesel crop. The results further showed that biosludge alone and in combination with biofertilizer significantly improved the survival rates and enhanced the growth of the plant. With the amendments, the plant was able to grow and survive upto 500, 250 and 4,000 mg kg(-1) of As, Cr and Zn contaminated soils, respectively. The results also showed that zinc enhanced the growth of J. curcas more as compared to other metals contaminated soils. The heavy metal accumulation in plant increased with increasing concentrations of heavy metals in soil, where as a significant reduction in the metal uptake in plant was observed, when amended with biosludge and biofertilizer and biosludge alone. It seems that the organic matter present in the biosludge acted as metal chelator thereby reducing the toxicity of metals to the plant. Findings suggest that plantation of J. curcas may be promoted in metal contaminated soils, degraded soils or wasteland suitably after amending with organic waste.

  9. Bioleaching remediation of heavy metal-contaminated soils using Burkholderia sp. Z-90.

    Science.gov (United States)

    Yang, Zhihui; Zhang, Zhi; Chai, Liyuan; Wang, Yong; Liu, Yi; Xiao, Ruiyang

    2016-01-15

    Bioleaching is an environment-friendly and economical technology to remove heavy metals from contaminated soils. In this study, a biosurfactant-producing strain with capacity of alkaline production was isolated from cafeteria sewer sludge and its capability for removing Zn, Pb, Mn, Cd, Cu, and As was investigated. Phylogenetic analysis using 16S rDNA gene sequences confirmed that the strain belonged to Burkholderia sp. and named as Z-90. The biosurfactant was glycolipid confirmed by thin layer chromatography and Fourier-transform infrared spectroscopy. Z-90 broth was then used for bioleaching remediation of heavy metal-contaminated soils. The removal efficiency was 44.0% for Zn, 32.5% for Pb, 52.2% for Mn, 37.7% for Cd, 24.1% for Cu and 31.6% for As, respectively. Mn, Zn and Cd were more easily removed from soil than Cu, Pb and As, which was attributed to the presence of high acid-soluble fraction of Mn, Zn and Cd and high residual fraction of Cu, Pb and As. The heavy metal removal in soils was contributed to the adhesion of heavy metal-contaminated soil minerals with strain Z-90 and the formation of a metal complex with biosurfactant. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Review on utilization of biochar for metal-contaminated soil and sediment remediation.

    Science.gov (United States)

    Wang, Mingming; Zhu, Yi; Cheng, Lirong; Andserson, Bruce; Zhao, Xiaohui; Wang, Dayang; Ding, Aizhong

    2018-01-01

    Biochar is a carbon-neutral or even carbon-negative material produced through thermal decomposition of plant- and animal-based biomass under oxygen-limited conditions. Recently, there has been an increasing interest in the application of biochar as an adsorbent, soil ameliorant and climate mitigation approach in many types of applications. Metal-contaminated soil remediation using biochar has been intensively investigated in small-scale and pilot-scale trials with obtained beneficial results and multifaceted effects. But so far, the study and application of biochar in contaminated sediment management has been very limited, and this is also a worldwide problem. Nonetheless, there is reason to believe that the same multiple benefits can also be realized with these sediments due to similar mechanisms for stabilizing contaminants. This paper provides a review on current biochar properties and its use as a sorbent/amendment for metal-contaminated soil/sediment remediation and its effect on plant growth, fauna habits as well as microorganism communities. In addition, the use of biochar as a potential strategy for contaminated sediment management is also discussed, especially as regards in-situ planning. Finally, we highlight the possibility of biochar application as an effective amendment and propose further research directions to ensure the safe and sustainable use of biochar as an amendment for remediation of contaminated soil and sediment. Copyright © 2017. Published by Elsevier B.V.

  11. Effects of heavy-metal-contaminated soil on growth, phenology and biomass turnover of Hieracium piloselloides

    International Nuclear Information System (INIS)

    Ryser, Peter; Sauder, Wendy R.

    2006-01-01

    The effects of low levels of heavy metals on plant growth, biomass turnover and reproduction were investigated for Hieracium pilosella. Plants were grown for 12 weeks on substrates with different concentrations of heavy metals obtained by diluting contaminated soils with silica sand. To minimize effects of other soil factors, the substrates were limed, fertilized, and well watered. The more metal-contaminated soil the substrate contained, the lower the leaf production rate and the plant mass were, and the more the phenological development was delayed. Flowering phenology was very sensitive to metals. Leaf life span was reduced at the highest and the lowest metal levels, the latter being a result of advanced seed ripening. Even if the effect of low metal levels on plant growth may be small, the delayed and reduced reproduction may have large effects at population, community and ecosystem level, and contribute to rapid evolution of metal tolerance. - Flowering phenology shows a very sensitive response to heavy metal contamination of soils

  12. Utilization of grasses for potential biofuel production and phytoremediation of heavy metal contaminated soils.

    Science.gov (United States)

    Balsamo, Ronald A; Kelly, William J; Satrio, Justinus A; Ruiz-Felix, M Nydia; Fetterman, Marisa; Wynn, Rodd; Hagel, Kristen

    2015-01-01

    This research focuses on investigating the use of common biofuel grasses to assess their potential as agents of long-term remediation of contaminated soils using lead as a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy grass may be potentially useful for long-term phytoremediation of heavy metal contaminated soils and describe novel techniques to track and remove contaminants from inception to useful product. Enzymatic digestion and thermochemical approaches are being used to convert this lignocellulosic feedstock into useful product (sugars, ethanol, biocrude oil+biochar). Preliminary studies on enzymatic hydrolysis and fast pyrolysis of the Switchgrass materials that were grown in heavy metal contaminated soil and non-contaminated soils show that the presence of lead in the Switchgrass material feedstock does not adversely affect the outcomes of the conversion processes. These results indicate that the modest levels of contaminant uptake allow these grass species to serve as phytoremediation agents as well as feedstocks for biofuel production in areas degraded by industrial pollution.

  13. Metal contamination disturbs biochemical and microbial properties of calcareous agricultural soils of the Mediterranean area.

    Science.gov (United States)

    de Santiago-Martín, Ana; Cheviron, Natalie; Quintana, Jose R; González, Concepción; Lafuente, Antonio L; Mougin, Christian

    2013-04-01

    Mediterranean climate characteristics and carbonate are key factors governing soil heavy-metal accumulation, and low organic matter (OM) content could limit the ability of microbial populations to cope with resulting stress. We studied the effects of metal contamination on a combination of biological parameters in soils having these characteristics. With this aim, soils were spiked with a mixture of cadmium, copper, lead, and zinc, at the two limit values proposed by current European legislation, and incubated for ≤12 months. Then we measured biochemical (phosphatase, urease, β-galactosidase, arylsulfatase, and dehydrogenase activities) and microbial (fungal and bacterial DNA concentration by quantitative polymerase chain reaction) parameters. All of the enzyme activities were strongly affected by metal contamination and showed the following inhibition sequence: phosphatase (30-64 %) soils was attributed to the different proportion of fine mineral fraction, OM, crystalline iron oxides, and divalent cations in soil solution. The decrease of fungal DNA concentration in metal-spiked soils was negligible, whereas the decrease of bacterial DNA was ~1-54 % at the lowest level and 2-69 % at the highest level of contamination. The lowest bacterial DNA decrease occurred in soils with the highest OM, clay, and carbonate contents. Finally, regarding the strong inhibition of the biological parameters measured and the alteration of the fungal/bacterial DNA ratio, we provide strong evidence that disturbance on the system, even within the limiting values of contamination proposed by the current European Directive, could alter key soil processes. These limiting values should be established according to soil characteristics and/or revised when contamination is produced by a mixture of heavy metals.

  14. Estimation of Heavy Metals Contamination in the Soil of Zaafaraniya City Using the Neural Network

    Science.gov (United States)

    Ghazi, Farah F.

    2018-05-01

    The aim of this paper is to estimate the heavy metals Contamination in soils which can be used to determine the rate of environmental contamination by using new technique depend on design feedback neural network as an alternative accurate technique. The network simulates to estimate the concentration of Cadmium (Cd), Nickel (Ni), Lead (Pb), Zinc (Zn) and Copper (Cu). Then to show the accuracy and efficiency of suggested design we applied the technique in Al- Zafaraniyah in Baghdad city. The results of this paper show that the suggested networks can be successfully applied to the rapid and accuracy estimation of concentration of heavy metals.

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

    Science.gov (United States)

    Chon, Hyo-Taek

    2015-04-01

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

  16. Heavy Metals Contaminated Soil Project, Resource Recovery Project, and Dynamic Underground Stripping Project

    International Nuclear Information System (INIS)

    1994-02-01

    The Department of Energy (DOE) established the Office of Technology Development (EM-50) (OTD) as an element of Environmental Restoration and Waste Management (EM) in November, 1989. OTD has begun to search out, develop, test and demonstrate technologies that can now or in the future be applied to the enormous remediation problem now facing the DOE and the United States public in general. Technology demonstration projects have been designed to attack a separate problem as defined by DOE. The Heavy Metals Contaminated Soil Project was conceived to test and demonstrate off-the-shelf technologies (dominantly from the mining industry) that can be brought to bear on the problem of radionuclide and heavy metal contamination in soils and sediments. The Resource Recovery Project is tasked with identifying, developing, testing, and evaluating new and innovative technologies for the remediation of metal contaminated surface and groundwater. An innovative twist on this project is the stated goal of recovering the metals, formerly disposed of as a waste, for reuse and resale, thereby transforming them into a usable resource. Finally, the Dynamic Underground Stripping Project was developed to demonstrate and remediate underground spills of hydrocarbons from formations that are (1) too deep for excavation, and/or (2) require in-situ remediation efforts of long duration. This project has already been shown effective in reducing the time for remediation by conventional methods from an estimated 200 years at the Lawrence Livermore National Laboratory (LLNL) to less than one year. The savings in time and dollars from this technology alone can be immeasurable

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

    Science.gov (United States)

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

    2016-04-01

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

  18. Immobilizer-assisted management of metal-contaminated agricultural soils for safer food production.

    Science.gov (United States)

    Kim, Kwon-Rae; Kim, Jeong-Gyu; Park, Jeong-Sik; Kim, Min-Suk; Owens, Gary; Youn, Gyu-Hoon; Lee, Jin-Su

    2012-07-15

    Production of food crops on metal contaminated agricultural soils is of concern because consumers are potentially exposed to hazardous metals via dietary intake of such crops or crop derived products. Therefore, the current study was conducted to develop management protocols for crop cultivation to allow safer food production. Metal uptake, as influenced by pH change-induced immobilizing agents (dolomite, steel slag, and agricultural lime) and sorption agents (zeolite and compost), was monitored in three common plants representative of leafy (Chinese cabbage), root (spring onion) and fruit (red pepper) vegetables, in a field experiment. The efficiency of the immobilizing agents was assessed by their ability to decrease the phytoavailability of metals (Cd, Pb, and Zn). The fruit vegetable (red pepper) showed the least accumulation of Cd (0.16-0.29 mgkg(-1) DW) and Pb (0.2-0.9 mgkg(-1) DW) in edible parts regardless of treatment, indicating selection of low metal accumulating crops was a reasonable strategy for safer food production. However, safer food production was more likely to be achievable by combining crop selection with immobilizing agent amendment of soils. Among the immobilizing agents, pH change-induced immobilizers were more effective than sorption agents, showing decreases in Cd and Pb concentrations in each plant well below standard limits. The efficiency of pH change-induced immobilizers was also comparable to reductions obtained by 'clean soil cover' where the total metal concentrations of the plow layer was reduced via capping the surface with uncontaminated soil, implying that pH change-induced immobilizers can be practically applied to metal contaminated agricultural soils for safer food production. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    1989-03-01

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

  20. Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

    Science.gov (United States)

    Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

    2016-11-15

    An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Distribution and Analysis of Heavy Metals Contamination in Soil, Perlis, Malaysia

    Science.gov (United States)

    Nihla Kamarudzaman, Ain; Woo, Yee Shan; Jalil, Mohd Faizal Ab

    2018-03-01

    The concentration of six heavy metals such as Cu, Cr, Ni, Cd, Zn and Mn were studied in the soils around Perlis. The aim of the study is to assess the heavy metals contamination distribution due to industrialisation and agricultural activities. Soil samples were collected at depth of 0 - 15 cm in five stations around Perlis. The soil samples are subjected to soil extraction and the concentration of heavy metals was determined via ICP - OES. Overall concentrations of Cr, Cu, Zn, Ni, Cd and Mn in the soil samples ranged from 0.003 - 0.235 mg/L, 0.08 - 41.187 mg/L, 0.065 - 45.395 mg/L, 0.031 - 2.198 mg/L, 0.01 - 0.174 mg/L and 0.165 - 63.789 mg/L respectively. The concentration of heavy metals in the soil showed the following decreasing trend, Mn > Zn > Cu > Ni > Cr > Cd. From the result, the level of heavy metals in the soil near centralised Chuping industrial areas gives maximum value compared to other locations in Perlis. As a conclusion, increasing anthropogenic activities have influenced the environment, especially in increasing the pollution loading.

  2. Heavy metal contamination and risk assessment in water, paddy soil, and rice around an electroplating plant.

    Science.gov (United States)

    Liu, Jie; Zhang, Xue-Hong; Tran, Henry; Wang, Dun-Qiu; Zhu, Yi-Nian

    2011-11-01

    The objective of this paper is to assess the impact of long-term electroplating industrial activities on heavy metal contamination in agricultural soils and potential health risks for local residents. Water, soil, and rice samples were collected from sites upstream (control) and downstream of the electroplating wastewater outlet. The concentrations of heavy metals were determined by an atomic absorption spectrophotometer. Fractionation and risk assessment code (RAC) were used to evaluate the environmental risks of heavy metals in soils. The health risk index (HRI) and hazard index (HI) were calculated to assess potential health risks to local populations through rice consumption. Hazardous levels of Cu, Cr, and Ni were observed in water and paddy soils at sites near the plant. According to the RAC analysis, the soils showed a high risk for Ni and a medium risk for Cu and Cr at certain sites. The rice samples were primarily contaminated with Ni, followed by Cr and Cu. HRI values >1 were not found for any heavy metal. However, HI values for adults and children were 2.075 and 1.808, respectively. Water, paddy soil, and rice from the studied area have been contaminated by Cu, Cr, and Ni. The contamination of these elements is related to the electroplating wastewater. Although no single metal poses health risks for local residents through rice consumption, the combination of several metals may threaten the health of local residents. Cu and Ni are the key components contributing to the potential health risks.

  3. Remediation techniques for heavy metal-contaminated soils: Principles and applicability.

    Science.gov (United States)

    Liu, Lianwen; Li, Wei; Song, Weiping; Guo, Mingxin

    2018-08-15

    Globally there are over 20millionha of land contaminated by the heavy metal(loid)s As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with the present soil concentrations higher than the geo-baseline or regulatory levels. In-situ and ex-situ remediation techniques have been developed to rectify the heavy metal-contaminated sites, including surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation. These remediation techniques employ containment, extraction/removal, and immobilization mechanisms to reduce the contamination effects through physical, chemical, biological, electrical, and thermal remedy processes. These techniques demonstrate specific advantages, disadvantages, and applicability. In general, in-situ soil remediation is more cost-effective than ex-situ treatment, and contaminant removal/extraction is more favorable than immobilization and containment. Among the available soil remediation techniques, electrokinetic extraction, chemical stabilization, and phytoremediation are at the development stage, while the others have been practiced at full, field scales. Comprehensive assessment indicates that chemical stabilization serves as a temporary soil remediation technique, phytoremediation needs improvement in efficiency, surface capping and landfilling are applicable to small, serious-contamination sites, while solidification and vitrification are the last remediation option. The cost and duration of soil remediation are technique-dependent and site-specific, up to $500ton -1 soil (or $1500m -3 soil or $100m -2 land) and 15years. Treatability studies are crucial to selecting feasible techniques for a soil remediation project, with considerations of the type and degree of contamination, remediation goals, site characteristics, cost effectiveness, implementation time, and public acceptability. Copyright © 2018 Elsevier B.V. All rights

  4. Metal contamination of agricultural soils in the copper mining areas of Singhbhum shear zone in India

    Science.gov (United States)

    Giri, Soma; Singh, Abhay Kumar; Mahato, Mukesh Kumar

    2017-06-01

    The study was intended to investigate the heavy metal contamination in the agricultural soils of the copper mining areas in Singhbhum shear zone, India. The total concentrations of the metals were determined by inductively coupled plasma-mass spectrometer (ICPMS). Pollution levels were assessed by calculating enrichment factor (EF), geo-accumulation index (I_geo), contamination factors (CF), pollution load index ( PLI), Nemerow index and ecological risk index (RI). The metal concentrations in the soil samples exceeded the average shale values for almost all the metals. Principal component analysis resulted in extraction of three factors explaining 82.6% of the data variability and indicated anthropogenic contribution of Cu, Ni, Co, Cr, Mn and Pb. The EF and I_geo values indicated very high contamination with respect to Cu followed by As and Zn in the agricultural soils. The values of PLI, RI and Nemerow index, which considered the overall effect of all the studied metals on the soils, revealed that 50% of the locations were highly polluted with respect to metals. The pollution levels varied with the proximity to the copper mining and processing units. Consequently, the results advocate the necessity of periodic monitoring of the agricultural soils of the area and development of proper management strategies to reduce the metal pollution.

  5. 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.

  6. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

    Directory of Open Access Journals (Sweden)

    M. Adama

    2016-01-01

    Full Text Available Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (Igeo and pollution load indices (PLI were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69, Pb (143.80, Cr (99.30, and Cd (7.54 in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

  7. Associative diazotrophic bacteria in grass roots and soils from heavy metal contaminated sites.

    Science.gov (United States)

    Moreira, Fátima M S; Lange, Anderson; Klauberg-Filho, Osmar; Siqueira, José O; Nóbrega, Rafaela S A; Lima, Adriana S

    2008-12-01

    This work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (Zinc, Cadmium and NaCl tolerance in vitro, and protein profiles) and genotypically (16S rDNA sequencing), as compared to type strains of known diazotrophic species. Densities were evaluated by using NFb, Fam and JNFb media, commonly used for enrichment cultures of diazotrophic bacteria. Bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. Azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to Zn+2 and Cd+2, being Cd+2 more toxic than Zn+2. Among the most tolerant isolates (UFLA 1S, 1R, S181, S34 and S22), some (1R, S34 and S22) were more tolerant to heavy metals than rhizobia from tropical and temperate soils. The majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g L(-1) NaCl. Five isolates exhibited high dissimilarity in protein profiles, and the 16S rDNA sequence analysis of two of them revealed new sequences for Azospirillum.

  8. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site.

    Science.gov (United States)

    Adama, M; Esena, R; Fosu-Mensah, B; Yirenya-Tawiah, D

    2016-01-01

    Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

  9. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

    Science.gov (United States)

    Adama, M.; Esena, R.; Fosu-Mensah, B.; Yirenya-Tawiah, D.

    2016-01-01

    Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites. PMID:27034685

  10. Water-soluble organo-building blocks of aminoclay as a soil-flushing agent for heavy metal contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Chul [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Eun Jung [Advanced Biomass R and D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ko, Dong Ah [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Ji-Won, E-mail: jiwonyang@kaist.ac.kr [Department of Chemical and Biomolecular Engineering (BK21 program), KAIST, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Advanced Biomass R and D Center, KAIST, 291 Daehakno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer Aminoclays have synthesized using centered metals with aminopropyl silane. Black-Right-Pointing-Pointer Developed aminoclay has unique nano-sized and water-soluble properties. Black-Right-Pointing-Pointer Aminoclay showed high heavy metal capacity with metal ions and its less toxicity. Black-Right-Pointing-Pointer Aminoclay could be used to remediate heavy metals from soils an alternative soil-flushing agent. - Abstract: We demonstrated that water-soluble aminopropyl magnesium functionalized phyllosilicate could be used as a soil-flushing agent for heavy metal contaminated soils. Soil flushing has been an attractive means to remediate heavy metal contamination because it is less disruptive to the soil environment after the treatment was performed. However, development of efficient and non-toxic soil-flushing agents is still required. We have synthesized aminoclays with three different central metal ions such as magnesium, aluminum, and ferric ions and investigated applicability of aminoclays as soil flushing agents. Among them, magnesium (Mg)-centered aminoclay showed the smallest size distribution and superior water solubility, up to 100 mg/mL. Mg aminoclay exhibited cadmium and lead binding capacity of 26.50 and 91.31 mg/g of Mg clay, respectively, at near neutral pH, but it showed negligible binding affinity to metals in acidic conditions. For soil flushing with Mg clay at neutral pH showed cadmium and lead were efficiently extracted from soils by Mg clay, suggesting strong binding ability of Mg clay with cadmium and lead. As the organic matter and clay compositions increased in the soil, the removal efficiency by Mg clay decreased and the operation time increased.

  11. Water-soluble organo-building blocks of aminoclay as a soil-flushing agent for heavy metal contaminated soil

    International Nuclear Information System (INIS)

    Lee, Young-Chul; Kim, Eun Jung; Ko, Dong Ah; Yang, Ji-Won

    2011-01-01

    Highlights: ► Aminoclays have synthesized using centered metals with aminopropyl silane. ► Developed aminoclay has unique nano-sized and water-soluble properties. ► Aminoclay showed high heavy metal capacity with metal ions and its less toxicity. ► Aminoclay could be used to remediate heavy metals from soils an alternative soil-flushing agent. - Abstract: We demonstrated that water-soluble aminopropyl magnesium functionalized phyllosilicate could be used as a soil-flushing agent for heavy metal contaminated soils. Soil flushing has been an attractive means to remediate heavy metal contamination because it is less disruptive to the soil environment after the treatment was performed. However, development of efficient and non-toxic soil-flushing agents is still required. We have synthesized aminoclays with three different central metal ions such as magnesium, aluminum, and ferric ions and investigated applicability of aminoclays as soil flushing agents. Among them, magnesium (Mg)-centered aminoclay showed the smallest size distribution and superior water solubility, up to 100 mg/mL. Mg aminoclay exhibited cadmium and lead binding capacity of 26.50 and 91.31 mg/g of Mg clay, respectively, at near neutral pH, but it showed negligible binding affinity to metals in acidic conditions. For soil flushing with Mg clay at neutral pH showed cadmium and lead were efficiently extracted from soils by Mg clay, suggesting strong binding ability of Mg clay with cadmium and lead. As the organic matter and clay compositions increased in the soil, the removal efficiency by Mg clay decreased and the operation time increased.

  12. [Continuous remediation of heavy metal contaminated soil by co-cropping system enhanced with chelator].

    Science.gov (United States)

    Wei, Ze-Bin; Guo, Xiao-Fang; Wu, Qi-Tang; Long, Xin-Xian

    2014-11-01

    In order to elucidate the continuous effectiveness of co-cropping system coupling with chelator enhancement in remediating heavy metal contaminated soils and its environmental risk towards underground water, soil lysimeter (0.9 m x 0.9 m x 0.9 m) experiments were conducted using a paddy soil affected by Pb and Zn mining in Lechang district of Guangdong Province, 7 successive crops were conducted for about 2.5 years. The treatments included mono-crop of Sedum alfredii Hance (Zn and Cd hyperaccumulator), mono-crop of corn (Zea mays, cv. Yunshi-5, a low-accumulating cultivar), co-crop of S. alfredii and corn, and co-crop + MC (Mixture of Chelators, comprised of citric acid, monosodium glutamate waste liquid, EDTA and KCI with molar ratio of 10: 1:2:3 at the concentration of 5 mmol x kg(-1) soil). The changes of heavy metal concentrations in plants, soil and underground water were monitored. Results showed that the co-cropping system was suitable only in spring-summer seasons and significantly increased Zn and Cd phytoextraction. In autumn-winter seasons, the growth of S. alfredii and its phytoextraction of Zn and Cd were reduced by co-cropping and MC application. In total, the mono-crops of S. alfredii recorded a highest phytoextraction of Zn and Cd. However, the greatest reduction of soil Zn, Cd and Pb was observed with the co-crop + MC treatment, the reduction rates were 28%, 50%, and 22%, respectively, relative to the initial soil metal content. The reduction of this treatment was mainly attributed to the downwards leaching of metals to the subsoil caused by MC application. The continuous monitoring of leachates during 2. 5 year's experiment also revealed that the addition of MC increased heavy metal concentrations in the leaching water, but they did not significantly exceed the III grade limits of the underground water standard of China.

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

    Directory of Open Access Journals (Sweden)

    Andon Vassilev

    2004-01-01

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

  14. Ecological investigations on plant associations in differently disturbed heavy-metal contaminated soils of Great Britain

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, W

    1968-01-01

    In different areas of Great Britain comparing ecological studies have been made on disturbed and undisturbed heavy metal contaminated soils. In Grizedale (Pennine), sampling of an undisturbed transect having high levels of major nutrients showed marked differentiation within a small area, only related to the plant available levels of zinc, copper, and lead. However, studies on disturbed heavy metal soils and spoil-heaps revealed a low water capacity and a low supply of major nutrients, particularly of N and P. These suggest that here both the enrichment of heavy metals and the considerable decrease of other nutrients are important in determining the heavy metal vegetation, and in maintaining it against other species. The quantity of zinc in plants is not related to the total or plant-available amount of zinc in soil, but confirmed physiological experiments on the influence of phosphorus and different zinc compounds (complexed or inorganic) on the uptake and distribution of zinc in Thlaspi alpestre and Minnartia rerum. Also an antagonism between lead and copper was revealed. 24 references.

  15. [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.

  16. Heavy Metal Contamination in Urban Soils I Zinc Accumulation Phenomenon in Urban Environments as Clues of Study

    OpenAIRE

    KOMAI, Yutaka

    1981-01-01

    As an introduction of the continuing study on the heavy metal contamination in urban soils, zinc accumulation phenomenon observed in urban areas in south Osaka was reported. The survey of zinc concentration in soybean leaves taken in urban and suburban arable lands indicated its accumulation in a wide area. And a correlation between easy soluble zinc level in soils and leaf zinc content were shown. Zinc concentrations in suspended particles in air, falling dust and some water samples were che...

  17. Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

    OpenAIRE

    Fan, Yu; Zhu, Tingping; Li, Mengtong; He, Jieyi; Huang, Ruixue

    2017-01-01

    Background. Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. Methods. This research was conducted to determine lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), and antimony (Sb) concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Results. Local soil contaminati...

  18. Risks to humans and wildlife from metal contamination in soils/sediments at CERCLA sites

    International Nuclear Information System (INIS)

    Hitch, J.P.; Hovatter, P.S.; Opresko, D.M.; Sample, B.; Young, R.A.

    1994-01-01

    A common problem that occurs at DOD and DOE CERCLA sites is metal contamination in soils and aquatic sediments and the protection of humans and wildlife from potential exposure to this contamination. Consequently, the authors have developed a site-specific reference dose for mercury in sediments at the Oak Ridge Reservation and site-specific cleanup levels for certain metals, including arsenic and nickel, in soils at an Army ammunition plant. Another concern during remediation of these sites is that limited data are available to determine the direct risks to indigenous wildlife. Therefore, the authors have developed toxicological benchmarks for certain metals and metal compounds to be used as screening tools to determine the potential hazard of a contaminant to representative mammalian and avian wildlife species. These values should enable the Army and DOE to more accurately determine the risks to humans and wildlife associated with exposure to these contaminated media at their sites in order to achieve a more effective remediation. This effort is ongoing at ORNL with toxicological benchmarks also being developed for metal compounds and other chemicals of concern to DOD and DOE in order to address the potential hazard to

  19. Phytoremediation of metal-contaminated soil in temperate humid regions of British Columbia, Canada.

    Science.gov (United States)

    Padmavathiamma, Prabha K; Li, Loretta Y

    2009-08-01

    The suitability of five plant species was studied for phytoextraction and phytostabilisation in a region with temperate maritime climate of coastal British Columbia, Canada. Pot experiments were conducted using Lolium perenne L (perennial rye grass), Festuca rubra L (creeping red fescue), Helianthus annuus L (sunflower), Poa pratensis L (Kentucky bluegrass) and Brassica napus L (rape) in soils treated with three different metal (Cu, Pb, Mn, and Zn) concentrations. The bio-metric characters of plants in soils with multiple-metal contaminations, their metal accumulation characteristics, translocation properties and metal removal were assessed at different stages of plant growth, 90 and 120 DAS (days after sowing). Lolium was found to be suitable for the phytostabilisation of Cu and Pb, Festuca for Mn and Poa for Zn. Metal removal was higher at 120 than at 90 days after sowing, and metals concentrated more in the underground tissues with less translocation to the aboveground parts. Bioconcentration factors indicate that Festuca had the highest accumulation for Cu, Helianthus for Pb and Zn and Poa for Mn.

  20. Impact of heavy metal contamination on oxidative stress of Eisenia andrei and bacterial community structure in Tunisian mine soil.

    Science.gov (United States)

    Boughattas, Iteb; Hattab, Sabrine; Boussetta, Hamadi; Banni, Mohamed; Navarro, Elisabeth

    2017-08-01

    The aims of this work were firstly to study the effect of heavy metal-polluted soils from Tunisian mine on earthworm biochemical biomarkers and on bacterial communities and therefore to analyze the interaction between earth worms and bacterial communities in these contaminated soils. For this purpose, we had introduced earthworm Eisenia andrei in six soils: one from mine spoils and five from agricultural soils, establishing a gradient of contamination. The response of worms to the presence of heavy metal was analyzed at the biochemical and transcriptional levels. In a second time, the impact of worm on bacterial community structure was investigated using automated ribosomal intergenic spacer analysis (ARISA) fingerprinting. An impact of heavy metal-contaminated soils on the oxidative status of E. andrei was observed, but this effect was dependent of the level of heavy metal contamination. Moreover, our results demonstrate that the introduction of earthworms E. andrei has an impact on bacterial community; however, the major change was observed in the less contaminated site. Furthermore, a significant correlation between earthworm oxidative status biomarkers and bacterial community structure was observed, mainly in the mine spoils. Therefore, we contribute to a better understanding of the relationships between epigenic earthworms and bacterial communities in heavy metal-contaminated soils.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. Phytoextraction with Brassica napus L.: A tool for sustainable management of heavy metal contaminated soils

    International Nuclear Information System (INIS)

    Grispen, Veerle M.J.; Nelissen, Hans J.M.; Verkleij, Jos A.C.

    2006-01-01

    Phytoextraction is a promising tool to extract metals from contaminated soils and Brassica napus L. seems to be a possible candidate species for this purpose. To select accessions with the ability to accumulate cadmium, hydroponically grown 21 day old seedlings of 77 B. napus L. accessions were exposed to 0.2 μM CdSO 4 for an additional 10 days. The effects of Cd on several parameters were quantified i.e.; shoot Cd concentration ([Cd] shoot ), total amount of Cd in shoots (Total Cd) and the shoot to root Cd concentration ratio (S/R ratio). Though generally natural variation was low for [Cd] shoot , Total Cd and S/R ratio, a number of accessions could be selected. Our results indicated that Total Cd and S/R ratio are independent parameters for Cd accumulation and translocation. The selected varieties were then tested in field experiments on two locations nearby metal smelters. The two locations differed in extractable soil Cd, Zn, Ca concentration and pH levels. On both locations B. napus L. accessions showed significant differences in [Cd] shoot and Total Cd. Furthermore we found significant correlations between Cd and Zn accumulation in shoots. There were site-specific effects with respect to Cd accumulation in the B. napus L. accessions, however, two accessions seem to perform equally well on both sites. The results of the field experiment suggest that certain B. napus L. accessions are suitable for phytoextraction of moderately heavy metal contaminated soils. - A screening for natural variation in Cd accumulated by 77 Brassica napus L. yielded candidate phytoextraction accessions for agricultural practice

  3. Phytoextraction with Brassica napus L.: A tool for sustainable management of heavy metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Grispen, Veerle M.J. [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands); Nelissen, Hans J.M. [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands); Verkleij, Jos A.C. [Department of Ecology and Physiology of Plants, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam (Netherlands)]. E-mail: jos.verkleij@falw.vu.nl

    2006-11-15

    Phytoextraction is a promising tool to extract metals from contaminated soils and Brassica napus L. seems to be a possible candidate species for this purpose. To select accessions with the ability to accumulate cadmium, hydroponically grown 21 day old seedlings of 77 B. napus L. accessions were exposed to 0.2 {mu}M CdSO{sub 4} for an additional 10 days. The effects of Cd on several parameters were quantified i.e.; shoot Cd concentration ([Cd]{sub shoot}), total amount of Cd in shoots (Total Cd) and the shoot to root Cd concentration ratio (S/R ratio). Though generally natural variation was low for [Cd]{sub shoot}, Total Cd and S/R ratio, a number of accessions could be selected. Our results indicated that Total Cd and S/R ratio are independent parameters for Cd accumulation and translocation. The selected varieties were then tested in field experiments on two locations nearby metal smelters. The two locations differed in extractable soil Cd, Zn, Ca concentration and pH levels. On both locations B. napus L. accessions showed significant differences in [Cd]{sub shoot} and Total Cd. Furthermore we found significant correlations between Cd and Zn accumulation in shoots. There were site-specific effects with respect to Cd accumulation in the B. napus L. accessions, however, two accessions seem to perform equally well on both sites. The results of the field experiment suggest that certain B. napus L. accessions are suitable for phytoextraction of moderately heavy metal contaminated soils. - A screening for natural variation in Cd accumulated by 77 Brassica napus L. yielded candidate phytoextraction accessions for agricultural practice.

  4. Sustainability likelihood of remediation options for metal-contaminated soil/sediment.

    Science.gov (United States)

    Chen, Season S; Taylor, Jessica S; Baek, Kitae; Khan, Eakalak; Tsang, Daniel C W; Ok, Yong Sik

    2017-05-01

    Multi-criteria analysis and detailed impact analysis were carried out to assess the sustainability of four remedial alternatives for metal-contaminated soil/sediment at former timber treatment sites and harbour sediment with different scales. The sustainability was evaluated in the aspects of human health and safety, environment, stakeholder concern, and land use, under four different scenarios with varying weighting factors. The Monte Carlo simulation was performed to reveal the likelihood of accomplishing sustainable remediation with different treatment options at different sites. The results showed that in-situ remedial technologies were more sustainable than ex-situ ones, where in-situ containment demonstrated both the most sustainable result and the highest probability to achieve sustainability amongst the four remedial alternatives in this study, reflecting the lesser extent of off-site and on-site impacts. Concerns associated with ex-situ options were adverse impacts tied to all four aspects and caused by excavation, extraction, and off-site disposal. The results of this study suggested the importance of considering the uncertainties resulting from the remedial options (i.e., stochastic analysis) in addition to the overall sustainability scores (i.e., deterministic analysis). The developed framework and model simulation could serve as an assessment for the sustainability likelihood of remedial options to ensure sustainable remediation of contaminated sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Spatial distribution of heavy metal contamination in soils near a primitive e-waste recycling site.

    Science.gov (United States)

    Quan, Sheng-Xiang; Yan, Bo; Yang, Fan; Li, Ning; Xiao, Xian-Ming; Fu, Jia-Mo

    2015-01-01

    The total concentrations of 12 heavy metals in surface soils (SS, 0-20 cm), middle soils (MS, 30-50 cm) and deep soils (DS, 60-80 cm) from an acid-leaching area, a deserted paddy field and a deserted area of Guiyu were measured. The results showed that the acid-leaching area was heavily contaminated with heavy metals, especially in SS. The mean concentrations of Ni, Cu, Zn, Cd, Sn, Sb and Pb in SS from the acid-leaching area were 278.4, 684.1, 572.8, 1.36, 3,472, 1,706 and 222.8 mg/kg, respectively. Heavy metal pollution in the deserted paddy field was mainly concentrated in SS and MS. The average values of Sb in SS and MS from the deserted paddy field were 16.3 and 20.2 mg/kg, respectively. However, heavy metal contamination of the deserted area was principally found in the DS. Extremely high concentrations of heavy metals were also observed at some special research sites, further confirming that the level of heavy metal pollution was very serious. The geoaccumulation index (Igeo) values revealed that the acid-leaching area was severely polluted with heavy metals in the order of Sb > Sn > Cu > Cd > Ni > Zn > Pb, while deserted paddy field was contaminated predominately by metals in the order of Sb > Sn > Cu. It was obvious that the concentrations of some uncommon contaminants, such as Sb and Sn, were higher than principal contaminants, such as Ni, Cu, Zn and Pb, suggesting that particular attention should be directed to Sn and Sb contamination in the future research of heavy metals in soils from e-waste-processing areas. Correlation analysis suggested that Li and Be in soils from the acid-leaching area and its surrounding environment might have originated from other industrial activities and from batteries, whereas Ni, Cu, Zn, Cd, Pb, Sn and Sb contamination was most likely caused by uncontrolled electronic waste (e-waste) processing. These results indicate the significant need for optimisation of e-waste-dismantling technologies and remediation of polluted soil

  6. 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...

  7. Metal accumulation in plants with added economical value grown on metal contaminated soils: sustainable use of these soils for bio-energy production and possibilities for phyto extraction

    International Nuclear Information System (INIS)

    Vangronsveld, J.; Boulet, J.; Weyens, N.; Meers, E.; Meiresonne, L.; Colpaert, J.; Thewys, T.; Lelie, D. van der; Carleer, R.; Ruttens, A.

    2009-01-01

    Phyto remediation has been proposed as an economic alternative for remediation of metal contaminated soils. It can be applied over extended surface areas and targets the bioavailable soil fraction of heavy metals, which is the most relevant fraction from an environmental risk assessment perspective. The most important drawback is the long remediation period required (years to decades). (Author)

  8. Aging and temperature effects on DOC and elemental release from a metal contaminated soil

    International Nuclear Information System (INIS)

    Martinez, C.E.; Jacobson, A.R.; McBride, M.B.

    2003-01-01

    Increased aging and temperatures may affect DOC element complexes and their release. - The combined effect of time and temperature on elemental release and speciation from a metal contaminated soil (Master Old Site, MOS) was investigated. The soil was equilibrated at 10, 28, 45, 70 and 90 deg. C for 2 days, 2 weeks, and 2 months in the laboratory. Dissolved organic carbon (DOC), total soluble elements (by ICP), and labile metals (by DPASV) were determined in the filtered (0.22 μm) supernatants. For the samples equilibrated at 90 deg. C, DOC fractions were size fractionated by filtration and centrifugation; a subsample was only centrifuged while another was also filtered through a 0.45 μm filter. Analyses of the supernatants (ICP, DPASV, DOC) were performed on all size fraction subsamples. Dissolved organic carbon (DOC) increased both with temperature and incubation time; however, metal behavior was not as uniform. In general, total soluble metal release (ICP) paralleled the behavior of DOC, increasing with both time and temperature, and confirming the importance of soil organic matter (SOM) in metal retention. Voltammetric analysis (dpasv) of Cu and Zn showed that very little of these metals remains labile in solution due, presumably, to complexation with dissolved organic matter. Labile concentrations of Cd, on the other hand, constituted a significant portion (50%) of total soluble Cd. Copper and Al increased in solution with time (up to 2 months) and temperature up to 70 deg. C; however, at 90 deg. C the soluble concentration declined sharply. The same behavior was observed after equilibration for longer periods of time (550 days) at lower temperatures (23 and 70 deg. C). While concentrations of labile Cu and total soluble Cu and Al increased in the unfiltered samples, the trend remained the same. DPASV analysis showing shifts in labile Cu complexes with temperature and time, together with the results from the unfiltered samples, lead to the hypothesis that Cu

  9. The study of metal contamination in urban soils of Hong Kong using a GIS-based approach

    International Nuclear Information System (INIS)

    Li Xiangdong; Lee Siulan; Wong Szechung; Shi Wenzhong; Thornton, Iain

    2004-01-01

    The study of regional variations and the anthropogenic contamination by metals of soils is very important for environmental planning and monitoring in urban areas. An extensive survey was conducted in the highly urbanized Kowloon area (46.9 km 2 ) of Hong Kong, using a systematic sampling strategy with a sampling density of 3-5 composite soil samples (0-15 cm) per km 2 . Geochemical maps of 'total' metals (Cd, Cr, Cu, Ni, Pb and Zn) from strong acid extraction in the surface soils were produced based on geographical information system (GIS) technology. A significant spatial relationship was found for Ni, Cu, Pb and Zn in the soils using a GIS-based analysis, suggesting that these metal contaminants in the soils of the Kowloon area had common sources. Several hot-spot areas of metal contamination were identified from the composite metal geochemical map, mainly in the old industrial and residential areas. A further GIS analysis revealed that road junctions, major roads and industrial buildings were possible sources of heavy metals in the urban soils. The Pb isotope composition of the contaminated soils showed clear anthropogenic origins. - GIS can be used to identify soil contamination hot-spot areas and to assess potential pollutant sources in an urban community

  10. The EDTA effect on phytoextraction of single and combined metals-contaminated soils using rainbow pink (Dianthus chinensis).

    Science.gov (United States)

    Lai, Hung-Yu; Chen, Zueng-Sang

    2005-08-01

    Rainbow pink (Dianthus chinensis), a potential phytoextraction plant, can accumulate high concentrations of Cd from metal-contaminated soils. The soils used in this study were artificially added with different metals including (1) CK: original soil, (2) Cd-treated soil: 10 mg Cd kg(-1), (3) Zn-treated soil: 100 mg Zn kg(-1), (4) Pb-treated soil: 1000 mg Pb kg(-1), (5) Cd-Zn-treated soil: 10 mg Cd kg(-1) and 100 mg Zn kg(-1), (6) Cd-Pb-treated soil: 10 mg Cd kg(-1) and 1000 mg Pb kg(-1), (7) Zn-Pb-treated soil: 100 mg Zn kg(-1) and 1000 mg Pb kg(-1), and (8) Cd-Zn-Pb-treated soil: 10 mg Cd kg(-1), 100 mg Zn kg(-1), and 1000 mg Pb kg(-1). Three concentrations of 2Na-EDTA solutions (0 (control), 2, and 5 mmol kg(-1) soil) were added to the different metals-treated soils to study the influence of applied EDTA on single and combined metals-contaminated soils phytoextraction using rainbow pink. The results showed that the Cd, Zn, Pb, Fe, or Mn concentrations in different metals-treated soil solutions significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). The metal concentrations in different metals-treated soils extracted by deionized water also significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). Because of the high extraction capacity of both 0.005 M DTPA (pH 5.3) and 0.05 M EDTA (pH 7.0), applying EDTA did not significantly increase the Cd, Zn, or Pb concentration in both extracts for most of the treatments. Applying EDTA solutions can significantly increase the Cd and Pb concentrations in the shoots of rainbow pink (p<0.05). However, this was not statistically significant for Zn because of the low Zn concentration added into the contaminated soils. The results from this study indicate that applying 5 mmol EDTA kg(-1) can significantly increase the Cd, Zn, or Pb concentrations both in the soil solution or extracted using deionized water in single or combined metals-contaminated soils, thus increasing the accumulated metals concentrations in

  11. Metal availability and soil toxicity after repeated croppings of Thlaspi caerulescens in metal contaminated soils

    International Nuclear Information System (INIS)

    Keller, Catherine; Hammer, Daniel

    2004-01-01

    Metal phytoextraction with hyperaccumulating plants could be a useful method to decontaminate soils, but it is not fully validated yet. In order to quantify the efficiency of Cd and Zn extraction from a calcareous soil with and without Fe amendment and an acidic soil, we performed a pot experiment with three successive croppings of Thlaspi caerulescens followed by 3 months without plant and 7 weeks with lettuce. We used a combined approach to assess total extraction efficiency (2 M HNO 3 -extractable metals), changes in metal bio/availability (0.1 M NaNO 3 -extractable metals and lettuce uptake) and toxicity (lettuce biomass and the BIOMETreg] biosensor). The soil solution was monitored over the whole experiment. In the calcareous soil large Cu concentrations were probably responsible for chlorosis symptoms observed on T. caerulescens. When this soil was treated with Fe, the amount of extracted metal by T. caerulescens increased and metal availability and soil toxicity decreased when compared to the untreated soil. In the acidic soil, T. caerulescens was most efficient: Cd and Zn concentrations in plants were in the range of hyperaccumulation and HNO 3 -extractable Cd and Zn, metal bio/availability, soil toxicity, and Cd and Zn concentrations in the soil solution decreased significantly. However, a reduced Cd concentration measured in the third T. caerulescens cropping indicated a decrease in metal availability below a critical threshold, whereas the increase of dissolved Cd and Zn concentrations after the third cropping may be the early sign of soil re-equilibration. This indicates that phytoextraction efficiency must be assessed by different approaches in order not to overlook any potential hazard and that an efficient phytoextraction scheme will have to take into account the different dynamics of the soil-plant system

  12. Assessment of toxicity of heavy metal contaminated soils for Collembola in the field and laboratory

    DEFF Research Database (Denmark)

    Xu, Jie; Krogh, Paul Henning; Luo, Yongming

    2008-01-01

    We present a field and laboratory investigation of effects of increasing levels of heavy metal contamination on the biodiversity and performance of collembolans. A 40 year old pollution with Cu, Zn, Pb and Cd pollution due to Cu smelting over 40 years was investigated in a paddy field area of Zhe...

  13. Using sequential indicator simulation to assess the uncertainty of delineating heavy-metal contaminated soils

    International Nuclear Information System (INIS)

    Juang, Kai-Wei; Chen, Yue-Shin; Lee, Dar-Yuan

    2004-01-01

    Mapping the spatial distribution of soil pollutants is essential for delineating contaminated areas. Currently, geostatistical interpolation, kriging, is increasingly used to estimate pollutant concentrations in soils. The kriging-based approach, indicator kriging (IK), may be used to model the uncertainty of mapping. However, a smoothing effect is usually produced when using kriging in pollutant mapping. The detailed spatial patterns of pollutants could, therefore, be lost. The local uncertainty of mapping pollutants derived by the IK technique is referred to as the conditional cumulative distribution function (ccdf) for one specific location (i.e. single-location uncertainty). The local uncertainty information obtained by IK is not sufficient as the uncertainty of mapping at several locations simultaneously (i.e. multi-location uncertainty or spatial uncertainty) is required to assess the reliability of the delineation of contaminated areas. The simulation approach, sequential indicator simulation (SIS), which has the ability to model not only single, but also multi-location uncertainties, was used, in this study, to assess the uncertainty of the delineation of heavy metal contaminated soils. To illustrate this, a data set of Cu concentrations in soil from Taiwan was used. The results show that contour maps of Cu concentrations generated by the SIS realizations exhausted all the spatial patterns of Cu concentrations without the smoothing effect found when using the kriging method. Based on the SIS realizations, the local uncertainty of Cu concentrations at a specific location of x', refers to the probability of the Cu concentration z(x') being higher than the defined threshold level of contamination (z c ). This can be written as Prob SIS [z(x')>z c ], representing the probability of contamination. The probability map of Prob SIS [z(x')>z c ] can then be used for delineating contaminated areas. In addition, the multi-location uncertainty of an area A

  14. Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation.

    Science.gov (United States)

    Roach, Nicole; Reddy, Krishna R; Al-Hamdan, Ashraf Z

    2009-06-15

    This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

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

    Science.gov (United States)

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

    2017-10-01

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

  16. Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation

    International Nuclear Information System (INIS)

    Roach, Nicole; Reddy, Krishna R.; Al-Hamdan, Ashraf Z.

    2009-01-01

    This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1 VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

  17. Associative diazotrophic bacteria in grass roots and soils from heavy metal contaminated sites

    Directory of Open Access Journals (Sweden)

    Fátima M.S. Moreira

    2008-12-01

    Full Text Available This work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (Zinc, Cadmium and NaCl tolerance in vitro, and protein profiles and genotypically (16S rDNA sequencing, as compared to type strains of known diazotrophic species. Densities were evaluated by using NFb, Fam and JNFb media, commonly used for enrichment cultures of diazotrophic bacteria. Bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. Azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to Zn+2 and Cd+2, being Cd+2 more toxic than Zn+2. Among the most tolerant isolates (UFLA 1S, 1R, S181, S34 and S22, some (1R, S34 and S22 were more tolerant to heavy metals than rhizobia from tropical and temperate soils. The majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g L-1 NaCl. Five isolates exhibited high dissimilarity in protein profiles, and the 16S rDNA sequence analysis of two of them revealed new sequences for Azospirillum.Objetivou-se avaliar a densidade de populações de bactérias diazotróficas associativas em amostras de solos e de raízes de gramíneas oriundas de sítios contaminados com metais pesados, e caracterizar isolados destas populações através da análise fenotípica (tolerância aos metais pesados zinco e cádmio e à NaCl in vitro, perfis protéicos, e genotípica (seqüenciamento de 16S rDNA, comparados às estirpes tipo das mesmas espécies. As densidades foram avaliadas nos meios NFb, Fam e LGI, comumente utilizados para culturas de enriquecimento de populações de bactérias diazotróficas associativas. As densidades

  18. Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam.

    Science.gov (United States)

    Nguyen Van, Thinh; Ozaki, Akinori; Nguyen Tho, Hoang; Nguyen Duc, Anh; Tran Thi, Yen; Kurosawa, Kiyoshi

    2016-11-05

    Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg -1 . Manganese and iron concentrations averaged 811 µg·g -1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment.

  19. Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam

    Directory of Open Access Journals (Sweden)

    Thinh Nguyen Van

    2016-11-01

    Full Text Available Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As, chromium (Cr, cadmium (Cd, copper (Cu, lead (Pb, and zinc (Zn concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg−1. Manganese and iron concentrations averaged 811 µg·g−1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment.

  20. A review of metal (Pb and Zn) sensitive and pH tolerant bioassay organisms for risk screening of metal-contaminated acidic soils

    International Nuclear Information System (INIS)

    Chapman, E.Emily V.; Dave, Göran; Murimboh, John D.

    2013-01-01

    To improve risk estimates at the screening stage of Ecological Risk Assessment (ERA), short duration bioassays tailored to undisturbed soil cores from the contaminated site could be useful. However, existing standardized bioassays use disturbed soil samples and often pH sensitive organisms. This is a problem as naturally acidic soils are widespread. Changing soil properties to suit the test organism may change metal bioavailability, leading to erroneous risk estimates. For bioassays in undisturbed soil cores to be effective, species able to withstand natural soil properties must be identified. This review presents a critical examination of bioassay species' tolerance of acidic soils and sensitivity to metal contaminants such as Pb and Zn. Promising organisms include; Dendrobaena octaedra, Folsomia candida, Caenorhabditis elegans, Oppia nitens, Brassica rapa, Trifolium pratense, Allium cepa, Quercus rubra and Acer rubrum. The MetSTICK test and the Bait lamina test were also identified as suitable microorganism tests. -- Highlights: •Risk screening of metal contaminated soils should consider metal bioavailability. •Metal bioavailability is dependent on soil properties such as pH. •Many standardized bioassay organisms are sensitive to acidic soils. •This review identifies acid tolerant and metal sensitive bioassays and species. •The identified tests can improve risk screening of acidic metal contaminated soil. -- This review identifies bioassay species able to withstand naturally acidic soils while being sensitive to metal contaminants

  1. Adaptation of soil microbial community structure and function to chronic metal contamination at an abandoned Pb-Zn mine.

    Science.gov (United States)

    Epelde, Lur; Lanzén, Anders; Blanco, Fernando; Urich, Tim; Garbisu, Carlos

    2015-01-01

    Toxicity of metals released from mine tailings may cause severe damage to ecosystems. A diversity of microorganisms, however, have successfully adapted to such sites. In this study, our objective was to advance the understanding of the indigenous microbial communities of mining-impacted soils. To this end, a metatranscriptomic approach was used to study a heavily metal-contaminated site along a metal concentration gradient (up to 3220 000 and 97 000 mg kg(-1) of Cd, Pb and Zn, respectively) resulting from previous mining. Metal concentration, soil pH and amount of clay were the most important factors determining the structure of soil microbial communities. Interestingly, evenness of the microbial communities, but not its richness, increased with contamination level. Taxa with high metabolic plasticity like Ktedonobacteria and Chloroflexi were found with higher relative abundance in more contaminated samples. However, several taxa belonging to the phyla Actinobacteria and Acidobacteria followed opposite trends in relation to metal pollution. Besides, functional transcripts related to transposition or transfer of genetic material and membrane transport, potentially involved in metal resistance mechanisms, had a higher expression in more contaminated samples. Our results provide an insight into microbial communities in long-term metal-contaminated environments and how they contrast to nearby sites with lower contamination. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Heavy metal contamination of surface soil in electronic waste dismantling area: site investigation and source-apportionment analysis.

    Science.gov (United States)

    Jinhui Li; Huabo Duan; Pixing Shi

    2011-07-01

    The dismantling and disposal of electronic waste (e-waste) in developing countries is causing increasing concern because of its impacts on the environment and risks to human health. Heavy-metal concentrations in the surface soils of Guiyu (Guangdong Province, China) were monitored to determine the status of heavy-metal contamination on e-waste dismantling area with a more than 20 years history. Two metalloids and nine metals were selected for investigation. This paper also attempts to compare the data among a variety of e-waste dismantling areas, after reviewing a number of heavy-metal contamination-related studies in such areas in China over the past decade. In addition, source apportionment of heavy metal in the surface soil of these areas has been analysed. Both the MSW open-burning sites probably contained invaluable e-waste and abandoned sites formerly involved in informal recycling activities are the new sources of soil-based environmental pollution in Guiyu. Although printed circuit board waste is thought to be the main source of heavy-metal emissions during e-waste processing, requirement is necessary to soundly manage the plastic separated from e-waste, which mostly contains heavy metals and other toxic substances.

  3. Ultrasonic and mechanical soil washing processes for the remediation of heavy-metal-contaminated soil

    Science.gov (United States)

    Kim, Seulgi; Lee, Wontae; Son, Younggyu

    2016-07-01

    Ultrasonic/mechanical soil washing process was investigated and compared with ultrasonic process and mechanical process using a relatively large lab-scale sonoreactor. It was found that higher removal efficiencies were observed in the combined processes for 0.1 and 0.3 M HCl washing liquids. It was due to the combination effects of macroscale removal for the overall range of slurry by mechanical mixing and microscale removal for the limited zone of slurry by cavitational actions.

  4. Heavy Metal Contamination in Urban Soils II Comparison of Urban Park Soils Between Two Cities with Different City and Industrial Activities

    OpenAIRE

    KOMAI, Yutaka

    1981-01-01

    A comparative investigation on the state of heavy metal contamination in park soils of two cities with different city and industrial activities was carried out. Sakai and Kishiwada, both situated in southern Osaka Prefecture, were chosen as the investigated cities which had similar natural conditions but different human activities. Park soils were regarded as suitable sites for the investigation of heavy metal problem in urban environments. Samples were taken at 34 parks distributed widely in...

  5. Assessment of ecological and human health risks of heavy metal contamination in agriculture soils disturbed by pipeline construction.

    Science.gov (United States)

    Shi, Peng; Xiao, Jun; Wang, Yafeng; Chen, Liding

    2014-02-28

    The construction of large-scale infrastructures such as nature gas/oil pipelines involves extensive disturbance to regional ecosystems. Few studies have documented the soil degradation and heavy metal contamination caused by pipeline construction. In this study, chromium (Cr), cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) levels were evaluated using Index of Geo-accumulation (Igeo) and Potential Ecological Risk Index (RI) values, and human health risk assessments were used to elucidate the level and spatial variation of heavy metal pollution risks. The results showed that the impact zone of pipeline installation on soil heavy metal contamination was restricted to pipeline right-of-way (RoW), which had higher Igeo of Cd, Cu, Ni and Pb than that of 20 m and 50 m. RI showed a declining tendency in different zones as follows: trench > working zone > piling area > 20 m > 50 m. Pipeline RoW resulted in higher human health risks than that of 20 m and 50 m, and children were more susceptible to non-carcinogenic hazard risk. Cluster analysis showed that Cu, Ni, Pb and Cd had similar sources, drawing attention to the anthropogenic activity. The findings in this study should help better understand the type, degree, scope and sources of heavy metal pollution from pipeline construction to reduce pollutant emissions, and are helpful in providing a scientific basis for future risk management.

  6. Assessment of Ecological and Human Health Risks of Heavy Metal Contamination in Agriculture Soils Disturbed by Pipeline Construction

    Directory of Open Access Journals (Sweden)

    Peng Shi

    2014-02-01

    Full Text Available The construction of large-scale infrastructures such as nature gas/oil pipelines involves extensive disturbance to regional ecosystems. Few studies have documented the soil degradation and heavy metal contamination caused by pipeline construction. In this study, chromium (Cr, cadmium (Cd, copper (Cu, nickel (Ni, lead (Pb and zinc (Zn levels were evaluated using Index of Geo-accumulation (Igeo and Potential Ecological Risk Index (RI values, and human health risk assessments were used to elucidate the level and spatial variation of heavy metal pollution risks. The results showed that the impact zone of pipeline installation on soil heavy metal contamination was restricted to pipeline right-of-way (RoW, which had higher Igeo of Cd, Cu, Ni and Pb than that of 20 m and 50 m. RI showed a declining tendency in different zones as follows: trench > working zone > piling area > 20 m > 50 m. Pipeline RoW resulted in higher human health risks than that of 20 m and 50 m, and children were more susceptible to non-carcinogenic hazard risk. Cluster analysis showed that Cu, Ni, Pb and Cd had similar sources, drawing attention to the anthropogenic activity. The findings in this study should help better understand the type, degree, scope and sources of heavy metal pollution from pipeline construction to reduce pollutant emissions, and are helpful in providing a scientific basis for future risk management.

  7. State of the Science Review: Potential for Beneficial Use of Waste By-Products for In-situ Remediation of Metal-Contaminated Soil and Sediment

    Science.gov (United States)

    Metal and metalloid contamination of soil and sediment is a widespread problem both in urban and rural areas throughout the United States (U.S. EPA, 2014). Beneficial use of waste by-products as amendments to remediate metal-contaminated soils and sediments can provide major eco...

  8. Assessment of Heavy Metals Contamination in Reclaimed Mine Soil and their Accumulation and Distribution in Eucalyptus Hybrid.

    Science.gov (United States)

    Maiti, Subodh Kumar; Rana, Vivek

    2017-01-01

    The metal contamination in reclaimed mine soil (RMS) of Jharia coal field, Dhanbad (India) using various contamination indices and their accumulation in tissues of Eucalyptus hybrid were assessed. In RMS, metal concentrations were found higher (202%-533%) than control soil (CS) with major contribution of Co and Mn followed by Zn, Cu and Pb. Principal component analysis (PCA) of metals present in RMS was carried out to assess their origin in RMS. The contamination factor (CF) values in RMS indicated moderate to very high level of pollution (ranged between 2.02 and 5.33). Higher accumulation of Pb in barks (three times), Zn in leaves (4.5 times), Mn in leaves (19 times), and Cu in roots (1.4 times) was found in trees growing on RMS than CS. The study concluded that different tree tissues accumulate varied concentration of heavy metals in RMS and thus for biomonitoring of metals, specific tissues has to be selected.

  9. Phytoextraction and phytostabilisation of metal-contaminated soil in temperate maritime climate of coastal British Columbia, Canada

    Science.gov (United States)

    Padmavathiamma, P. K.; Li, L. Y.

    2009-04-01

    This research addressed the phytoremediation of roadside soils subjected to multi-component metal solutions. A typical right of way for roads in Canada is around 30 m, and at least 33% of that land in the right of way is unpaved and can support animal life. Thus, land associated with 12,000 km of roads in the province of British Columbia and millions of kilometres around the world represent a substantial quantity of wildlife habitat where metal contamination needs to be remediated. Phytostabilisation, requires least maintenance among different phytoremediation techniques, and it could be a feasible and practical method of remediating in roadside soils along highways and for improving highway runoff drainage. The suitability of five plant species was studied for phytoextraction and phytostabilisation in a region with temperate maritime climate of coastal British Columbia, Canada. Pot experiments were conducted using Lolium perenne L (perennial rye grass), Festuca rubra L (creeping red fescue), Helianthus annuus L (sunflower), Poa pratensis L (Kentucky bluegrass) and Brassica napus L (rape) in soils treated with three different metal (Cu, Pb, Mn and Zn) concentrations. The bio-metric characters of plants in soils with multiple-metal contaminations, their metal accumulation characteristics, translocation properties and metal removal were assessed at different stages of plant growth, 90 and 120 DAS (days after sowing). Lolium was found to be suitable for the phytostabilisation of Cu and Pb, Festuca for Mn and Poa for Zn. Metal removal was higher at 120 than at 90 days after sowing, and metals concentrated more in the underground tissues with less translocation to the above-ground parts. Bioconcentration factors indicate that Festuca had the highest accumulation for Cu, Helianthus for Pb and Zn and Poa for Mn.

  10. Assessing the fate of antibiotic contaminants in metal contaminated soils four years after cessation of long-term waste water irrigation

    International Nuclear Information System (INIS)

    Tamtam, Fatima; Oort, Folkert van; Le Bot, Barbara; Dinh, Tuc; Mompelat, Sophie; Chevreuil, Marc; Lamy, Isabelle; Thiry, Medard

    2011-01-01

    Spreading of urban wastewater on agricultural land may lead to concomitant input of organic and inorganic pollutants. Such multiple pollution sites offer unique opportunities to study the fate of both heavy metals and pharmaceuticals. We examined the occurrence and fate of selected antibiotics in sandy-textured soils, sampled four years after cessation of 100 years irrigation with urban wastewater from the Paris agglomeration. Previous studies on heavy metal contamination of these soils guided our sampling strategy. Six antibiotics were studied, including quinolones, with a strong affinity for organic and mineral soil components, and sulfonamides, a group of more mobile molecules. Bulk samples were collected from surface horizons in different irrigation fields, but also in subsurface horizons in two selected profiles. In surface horizons, three quinolones (oxolinic acid, nalidixic acid, and flumequine) were present in eight samples out of nine. Their contents varied spatially, but were well-correlated one to another. Their distributions showed great similarities regarding spatial distribution of total organic carbon and heavy metal contents, consistent with a common origin by wastewater irrigation. Highest concentrations were observed for sampling sites close to irrigation water outlets, reaching 22 μg kg -1 for nalidixic acid. Within soil profiles, the two antibiotic groups demonstrated an opposite behavior: quinolones, found only in surface horizons; sulfamethoxazole, detected in clay-rich subsurface horizons, concomitant with Zn accumulation. Such distribution patterns are consistent with chemical adsorption properties of the two antibiotic groups: immobilization of quinolones in the surface horizons ascribed to strong affinity for organic matter (OM), migration of sulfamethoxazole due to a lower affinity for OM and its interception and retention in electronegative charged clay-rich horizons. Our work suggests that antibiotics may represent a durable

  11. Human health risk from soil heavy metal contamination under different land uses near Dabaoshan Mine, Southern China

    International Nuclear Information System (INIS)

    Zhao, Huarong; Xia, Beicheng; Fan, Chen; Zhao, Peng; Shen, Shili

    2012-01-01

    Soil heavy metal contamination is a major environmental concern, and the ecological risk associated with heavy metals is increasing. In this paper, we investigated heavy metal contamination near Dabaoshan Mine by: using sequential indicator simulation to delineate the spatial patterns of soil data; fitting multiple linear regression models for heavy metal uptake by crops; interpreting land uses from remote sensing images and integrating the spatial patterns, uptake models and land uses into a dose–response model for human health risks from heavy metals. The areas with elevated soil heavy metal concentrations are mainly located at the Dabaoshan Mine site and in the watershed basins of the Hengshi, Tielong and Chuandu rivers. The average concentrations of Cu, Zn, Cd and Pb in soil in the study area are all above the natural soil background levels, but Cd is the major contributor to human health risk in the area. Areas of low soil pH are also found throughout the watershed basins of the Hengshi, Tielong and Chuandu rivers. Of the different land use types in the study area, agricultural and residential land uses have the highest human health risk because ingestion is the dominant exposure pathway for heavy metals. The spatial patterns of the heavy metal concentrations and soil pH indicate that the areas with the highest human health risk regions do not directly coincide with the areas of highest heavy metal concentrations, but do coincide with the areas of lower soil pH. The contamination with high concentrations of heavy metals provides the risk source, but the combination of high heavy metal concentrations, low pH and agricultural or residential land use is required for human health risks to be present. The spatial pattern of the hazard quotients indicates that Cd is the most important pollutant contributing to the human health risk. - Highlights: ►The distribution of Cu, Zn, Cd, Pb and pH in soil were analyzed near Dabaoshan Mine. ►Heavy metal uptake models in

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

    Science.gov (United States)

    Abraham, Joji; Dowling, Kim; Florentine, Singarayer

    2018-02-01

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

  13. Assessment of heavy metals contamination in surface layers of Roztocze National Park forest soils (SE Poland) by indices of pollution.

    Science.gov (United States)

    Mazurek, Ryszard; Kowalska, Joanna; Gąsiorek, Michał; Zadrożny, Paweł; Józefowska, Agnieszka; Zaleski, Tomasz; Kępka, Wojciech; Tymczuk, Maryla; Orłowska, Kalina

    2017-02-01

    In most cases, in soils exposed to heavy metals accumulation, the highest content of heavy metals was noted in the surface layers of the soil profile. Accumulation of heavy metals may occur both as a result of natural processes as well as anthropogenic activities. The quality of the soil exposed to heavy metal contamination can be evaluated by indices of pollution. On the basis of determined heavy metals (Pb, Zn, Cu, Mn, Ni and Cr) in the soils of Roztocze National Park the following indices of pollution were calculated: Enrichment Factor (EF), Geoaccumulation Index (I geo ), Nemerow Pollution Index (PI Nemerow ) and Potential Ecological Risk (RI). Additionally, we introduced and calculated the Biogeochemical Index (BGI), which supports determination of the ability of the organic horizon to accumulate heavy metals. A tens of times higher content of Pb, Zn, Cu and Mn was found in the surface layers compared to their content in the parent material. This distribution of heavy metals in the studied soils was related to the influence of anthropogenic pollution (both local and distant sources of emission), as well as soil properties such as pH, organic carbon and total nitrogen content. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  15. VegeSafe: A community science program measuring soil-metal contamination, evaluating risk and providing advice for safe gardening.

    Science.gov (United States)

    Rouillon, Marek; Harvey, Paul J; Kristensen, Louise J; George, Steven G; Taylor, Mark P

    2017-03-01

    The extent of metal contamination in Sydney residential garden soils was evaluated using data collected during a three-year Macquarie University community science program called VegeSafe. Despite knowledge of industrial and urban contamination amongst scientists, the general public remains under-informed about the potential risks of exposure from legacy contaminants in their home garden environment. The community was offered free soil metal screening, allowing access to soil samples for research purposes. Participants followed specific soil sampling instructions and posted samples to the University for analysis with a field portable X-ray Fluorescence (pXRF) spectrometer. Over the three-year study period, >5200 soil samples, primarily from vegetable gardens, were collected from >1200 Australian homes. As anticipated, the primary soil metal of concern was lead; mean concentrations were 413 mg/kg (front yard), 707 mg/kg (drip line), 226 mg/kg (back yard) and 301 mg/kg (vegetable garden). The Australian soil lead guideline of 300 mg/kg for residential gardens was exceeded at 40% of Sydney homes, while concentrations >1000 mg/kg were identified at 15% of homes. The incidence of highest soil lead contamination was greatest in the inner city area with concentrations declining towards background values of 20-30 mg/kg at 30-40 km distance from the city. Community engagement with VegeSafe participants has resulted in useful outcomes: dissemination of knowledge related to contamination legacies and health risks; owners building raised beds containing uncontaminated soil and in numerous cases, owners replacing all of their contaminated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Effects of rapeseed residue on lead and cadmium availability and uptake by rice plants in heavy metal contaminated paddy soil.

    Science.gov (United States)

    Ok, Yong Sik; Usman, Adel R A; Lee, Sang Soo; Abd El-Azeem, Samy A M; Choi, Bongsu; Hashimoto, Yohey; Yang, Jae E

    2011-10-01

    Rapeseed (Brassica napus L.) has been cultivated for biodiesel production worldwide. Winter rapeseed is commonly grown in the southern part of Korea under a rice-rapeseed double cropping system. In this study, a greenhouse pot experiment was conducted to assess the effects of rapeseed residue applied as a green manure alone or in combinations with mineral N fertilizer on Cd and Pb speciation in the contaminated paddy soil and their availability to rice plant (Oryza sativa L.). The changes in soil chemical and biological properties in response to the addition of rapeseed residue were also evaluated. Specifically, the following four treatments were evaluated: 100% mineral N fertilizer (N100) as a control, 70% mineral N fertilizer+rapeseed residue (N70+R), 30% mineral N fertilizer+rapeseed residue (N30+R) and rapeseed residue alone (R). The electrical conductivity and exchangeable cations of the rice paddy soil subjected to the R treatment or in combinations with mineral N fertilizer treatment, N70+R and N30+R, were higher than those in soils subjected to the N100 treatment. However, the soil pH value with the R treatment (pH 6.3) was lower than that with N100 treatment (pH 6.9). Use of rapeseed residue as a green manure led to an increase in soil organic matter (SOM) and enhanced the microbial populations in the soil. Sequential extraction also revealed that the addition of rapeseed residue decreased the easily accessible fraction of Cd by 5-14% and Pb by 30-39% through the transformation into less accessible fractions, thereby reducing metal availability to the rice plant. Overall, the incorporation of rapeseed residue into the metal contaminated rice paddy soils may sustain SOM, improve the soil chemical and biological properties, and decrease the heavy metal phytoavailability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    International Nuclear Information System (INIS)

    Voglar, Grega E.; Lestan, Domen

    2011-01-01

    Highlights: → We assess the feasibility of using soil S/S for industrial land reclamation. → Retarders, accelerators, plasticizers were used in S/S cementitious formulation. → We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg -1 of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm -2 achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  18. Metal contamination in urban, suburban, and country park soils of Hong Kong: A study based on GIS and multivariate statistics

    International Nuclear Information System (INIS)

    Lee, Celine Siu-lan; Li Xiangdong; Shi Wenzhong; Cheung, Sharon Ching-nga; Thornton, Iain

    2006-01-01

    The urban environment quality is of vital importance as the majority of people now live in cities. Due to the continuous urbanisation and industrialisation in many parts of the world, metals are continuously emitted into the terrestrial environment and pose a great threat on human health. An extensive survey was conducted in the highly urbanised and commercialised Hong Kong Island area (80.3 km 2 ) of Hong Kong using a systematic sampling strategy of five soil samples per km 2 in urban areas and two samples per km 2 in the suburban and country park sites (0-15 cm). The analytical results indicated that the surface soils in urban and suburban areas are enriched with metals, such as Cu, Pb, and Zn. The Pb concentration in the urban soils was found to exceed the Dutch target value. The statistical analyses using principal component analysis (PCA) and cluster analysis (CA) showed distinctly different associations among trace metals and the major elements (Al, Ca, Fe, Mg, Mn) in the urban, suburban, and country park soils. Soil pollution maps of trace metals (Cd, Co, Cr, Cu, Ni, Pb, and Zn) in the surface soils were produced based on geographical information system (GIS) technology. The hot-spot areas of metal contamination were mainly concentrated in the northern and western parts of Hong Kong Island, and closely related to high traffic conditions. The Pb isotopic composition of the urban, suburban, and country park soils showed that vehicular emissions were the major anthropogenic sources for Pb. The 206 Pb/ 207 Pb and 208 Pb/ 207 Pb ratios in soils decreased as Pb concentrations increased in a polynomial line (degree = 2)

  19. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives

    Energy Technology Data Exchange (ETDEWEB)

    Voglar, Grega E. [RDA - Regional Development Agency Celje, Kidriceva ulica 25, 3000 Celje (Slovenia); Lestan, Domen, E-mail: domen.lestan@bf.uni-lj.si [Agronomy Department, Centre for Soil and Environmental Science, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana (Slovenia)

    2011-08-30

    Highlights: {yields} We assess the feasibility of using soil S/S for industrial land reclamation. {yields} Retarders, accelerators, plasticizers were used in S/S cementitious formulation. {yields} We proposed novel S/S efficiency model for multi-metal contaminated soils. - Abstract: In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085 mg kg{sup -1} of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12 N mm{sup -2} achieved after S/S with CAC + PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC + Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively.

  20. Assessing the effects of FBC ash treatments of metal-contaminated soils using life history traits and metal bioaccumulation analysis of the earthworm Eisenia andrei

    Energy Technology Data Exchange (ETDEWEB)

    Grumiaux, F.; Demuynck, S.; Schikorski, D.; Lemiere, S.; Lepretre, A. [Universite Lille Nord de France, Villeneuve Dascq (France)

    2010-03-15

    Earthworms (Eisenia andrei) were exposed, in controlled conditions, to metal-contaminated soils previously treated in situ with two types of fluidized bed combustion ashes. Effects on this species were determined by life history traits analysis. Metal immobilizing efficiency of ashes was indicated by metal bioaccumulation. Ashes-treated soils reduced worm mortality compared to the untreated soil. However, these ashes reduced both cocoon hatching success and hatchlings numbers compared to the untreated soil. In addition, sulfo-calcical ashes reduced or delayed worm maturity and lowered cocoon production compared to silico-alumineous ones. Metal immobilizing efficiency of ashes was demonstrated for Zn, Cu and to a lesser extent Pb. Only silico-alumineous ashes reduced Cd bioaccumulation, although Cd was still bioconcentrated. Thus, although ash additions to metal-contaminated soils may help in immobilizing metals, their use might result, depending on the chemical nature of ashes, to severe detrimental effects on earthworm reproduction with possible long term consequences to populations.

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

    Science.gov (United States)

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

    2014-06-01

    A cadmium/zinc hyperaccumulator extracted metals from four contaminated soils over three years in a glasshouse experiment. Changes in plant metal uptake and soil total (aqua regia-extractable) and available metals were investigated. Plant Cd concentrations in a high-Cd acid soil and plant Zn concentrations in two acid soils decreased during repeated phytoextraction and were predicted by soil available metal concentrations. However, on repeated phytoextraction, plant Cd concentrations remained constant in lightly Cd-polluted acid soils, as did plant Cd and Zn in alkaline soils, although soil available metal concentrations decreased markedly. After phytoextraction acid soils showed much higher total metal removal efficiencies, indicating possible suitability of phytoextraction for acid soils. However, DGT-testing, which takes soil metal re-supply into consideration, showed substantial removal of available metal and distinct decreases in metal supply capacity in alkaline soils after phytoextraction, suggesting that a strategy based on lowering the bioavailable contaminant might be feasible. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. 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.

  3. Adaptive sampling based on the cumulative distribution function of order statistics to delineate heavy-metal contaminated soils using kriging

    International Nuclear Information System (INIS)

    Juang, K.-W.; Lee, D.-Y.; Teng, Y.-L.

    2005-01-01

    Correctly classifying 'contaminated' areas in soils, based on the threshold for a contaminated site, is important for determining effective clean-up actions. Pollutant mapping by means of kriging is increasingly being used for the delineation of contaminated soils. However, those areas where the kriged pollutant concentrations are close to the threshold have a high possibility for being misclassified. In order to reduce the misclassification due to the over- or under-estimation from kriging, an adaptive sampling using the cumulative distribution function of order statistics (CDFOS) was developed to draw additional samples for delineating contaminated soils, while kriging. A heavy-metal contaminated site in Hsinchu, Taiwan was used to illustrate this approach. The results showed that compared with random sampling, adaptive sampling using CDFOS reduced the kriging estimation errors and misclassification rates, and thus would appear to be a better choice than random sampling, as additional sampling is required for delineating the 'contaminated' areas. - A sampling approach was derived for drawing additional samples while kriging

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

    OpenAIRE

    Chao Su; LiQin Jiang; WenJun Zhang

    2014-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  6. Helichrysum italicum growing on metalliferous areas as a potential tool in phytostabilization of metal-contaminated soils.

    Science.gov (United States)

    Bini, Claudio; Maleci, Laura; Giuliani, Claudia

    2015-04-01

    Plants that colonize metalliferous soils have developed physiological mechanisms that allow to tolerate high metal concentrations. Generally, metal uptake by these plants is not suppressed, but a detoxification process occurs, as a response to different strategies: some plants (accumulators) concentrate metals in the aerial parts, while others (excluders) present low metal concentrations in the aerial parts, since metals are arrested in their roots. In several regions of Italy (e.g. Veneto, Sardinia, Tuscany), numerous abandoned mine sites are present; On these metal-contaminated soils grow both metalliferous (e.g. Silene paradoxa) and non-metalliferous plants (e.g. Taraxacum officinale). Among them, Helichrysum italicum deserved attention since it is known as essential oil producer and is also used as a medicinal plant for its anti-inflammatory properties; for this reason, it must undergo the Drug Master File certifying the absence of chemical impurities and heavy metals. Samples of the whole plant (roots, leaves and flowers) of H. italicum have been collected at various sites, both mined and not mined, in order to ascertain its ability to uptake and translocate metals from roots to the aerial parts. Fresh and embedded material was examined by Light microscopy and Electron Microscopy (Scanning and Transmission) to ascertain possible damages in plant morphology. Dried samples were crushed, digested with HNO3 and analysed by ICP-OE technique for heavy metal (Cu, Fe, Mn, Zn) concentrations. Preliminary observations on the morphology of the different samples do not show significant differences in the leaf structure. The inorganic chemical composition of H. italicum was characterized by high metal content. Preliminary results of our analyses show that H. italicum accumulate metals (Mn, Zn) in roots, but do not translocate metals to the aerial parts; therefore, it may be considered an excluder plant. On the basis of our results, the aerial parts (leaves, flowers) of

  7. Heavy metals contamination of air and soil in Karak solid waste disposal site, Jordan

    International Nuclear Information System (INIS)

    Jiries, A. G.; Jaradat, Q. M.; Momani, K. A.

    1996-01-01

    The level of air and soil pollution in the municipal solid waste disposal site of Karak(Jordan) were investigated during spring of 1995 by monitoring the amounts of heavy metals. The concentration (mg/kg)of Cu, Pb, and Zn in the upper soil were found to have a range of 15.3-39.3, 21.2-38.0 and 60.0-127.0 respectively. However, for the lower soil, the ranges are 13.4-18.9, 18.5-23.7, and 50.6-90.4, respectively. The soil contamination with heavy metals was almost confined to the upper soil in the locations closely surrounding the burning site, which could be accounted to the arid climate conditions of the area. (authors). 20 refs., 3 tabs., 5 figs

  8. Heavy metal contamination in water, soil and a potential vegetable garlic (Allium sativum L.) in Punjab, Pakistan

    International Nuclear Information System (INIS)

    Khan, Z.I.; Ahmad, K.; Yasmeen, S.; Mehmood, N.

    2017-01-01

    Heavy metal contamination in soil, water, and garlic (Allium sativum L.) (watered with canal, ground and sewage waters) in a semi-arid region was investigated in this study. A sub-urban area of district Khushab, Pakistan was chosen as the study site to assess the risks associated with the consumption of this vegetable supplied with three different types of water for irrigation. Sewage water had higher contents of metals and metalloids (Cu, Ni, Se, Mo, As, Fe and Zn) than in other waters. Mean metal concentrations were below the permissible values, but those of Pb and Mo exceeded their respective limits. Metal correlation for the vegetable and soil was significantly positive except for Cu. The range of bio-concentration factor varied between 0.06-20.51 mg/kg. The sewage water had the highest pollution load index. Zinc had the highest daily intake value (0.199), while Se had the lowest value (0.003). The range for health index stood between 0.261-73.44 mg/kg. Metals like Zn, Ni and Cu had enrichment factor higher than 1.0 which raised serious health concerns. It has been a routine to irrigate crops with sewage water but proper management of wastewater is required prior to its supply to the fields. Hazardous quotient (HQ) indicated alarming levels of different metals with respect to public health due to utilization of this vegetable receiving wastewater irrigation. (author)

  9. Phytoremediation of Metal Contaminated Soil Using Willow: Exploiting Plant-Associated Bacteria to Improve Biomass Production and Metal Uptake.

    Science.gov (United States)

    Janssen, Jolien; Weyens, Nele; Croes, Sarah; Beckers, Bram; Meiresonne, Linda; Van Peteghem, Pierre; Carleer, Robert; Vangronsveld, Jaco

    2015-01-01

    Short rotation coppice (SRC) of willow and poplar is proposed for economic valorization and concurrently as remediation strategy for metal contaminated land in northeast-Belgium. However, metal phytoextraction appears insufficient to effectuate rapid reduction of soil metal contents. To increase both biomass production and metal accumulation of SRC, two strategies are proposed: (i) in situ selection of the best performing clones and (ii) bioaugmentation of these clones with beneficial plant-associated bacteria. Based on field data, two experimental willow clones, a Salix viminalis and a Salix alba x alba clone, were selected. Compared to the best performing commercial clones, considerable increases in stem metal extraction were achieved (up to 74% for Cd and 91% for Zn). From the selected clones, plant-associated bacteria were isolated and identified. All strains were subsequently screened for their plant growth-promoting and metal uptake enhancing traits. Five strains were selected for a greenhouse inoculation experiment with the selected clones planted in Cd-Zn-Pb contaminated soil. Extraction potential tended to increase after inoculation of S. viminalis plants with a Rahnella sp. strain due to a significantly increased twig biomass. However, although bacterial strains showing beneficial traits in vitro were used for inoculation, increments in extraction potential were not always observed.

  10. Heavy metal contamination of agricultural soils affected by mining activities around the Ganxi River in Chenzhou, Southern China.

    Science.gov (United States)

    Ma, Li; Sun, Jing; Yang, Zhaoguang; Wang, Lin

    2015-12-01

    Heavy metal contamination attracted a wide spread attention due to their strong toxicity and persistence. The Ganxi River, located in Chenzhou City, Southern China, has been severely polluted by lead/zinc ore mining activities. This work investigated the heavy metal pollution in agricultural soils around the Ganxi River. The total concentrations of heavy metals were determined by inductively coupled plasma-mass spectrometry. The potential risk associated with the heavy metals in soil was assessed by Nemerow comprehensive index and potential ecological risk index. In both methods, the study area was rated as very high risk. Multivariate statistical methods including Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis were employed to evaluate the relationships between heavy metals, as well as the correlation between heavy metals and pH, to identify the metal sources. Three distinct clusters have been observed by hierarchical cluster analysis. In principal component analysis, a total of two components were extracted to explain over 90% of the total variance, both of which were associated with anthropogenic sources.

  11. Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

    Directory of Open Access Journals (Sweden)

    Yu Fan

    2017-01-01

    Full Text Available Background. Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. Methods. This research was conducted to determine lead (Pb, cadmium (Cd, arsenic (As, manganese (Mn, and antimony (Sb concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Results. Local soil contamination was observed, with mean concentrations of Cd, Pb, Sb, and As of 0.472, 193.133, 36.793, and 89.029 mg/kg, respectively. Mean concentrations of Cd, Pb, Sb, Mn, and As in brown rice were 0.103, 0.131, 5.175, 6.007, and 0.524 mg/kg, respectively. Daily intakes of Cd, As, Sb, Pb, and Mn through brown rice consumption were estimated to be 0.011, 0.0002, 0.004, 0.0001, and 0.0003 mg/(kg/day, respectively. The combined hazard index for the five heavy metals was 22.5917, and the total cancer risk was 0.1773. Cd contributed most significantly to cancer risk, accounting for approximately 99.77% of this risk. Conclusions. The results show that potential noncarcinogenic and carcinogenic health risks exist for local inhabitants and that regular monitoring of pollution to protect human health is urgently required.

  12. Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China.

    Science.gov (United States)

    Fan, Yu; Zhu, Tingping; Li, Mengtong; He, Jieyi; Huang, Ruixue

    2017-01-01

    Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. This research was conducted to determine lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), and antimony (Sb) concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Local soil contamination was observed, with mean concentrations of Cd, Pb, Sb, and As of 0.472, 193.133, 36.793, and 89.029 mg/kg, respectively. Mean concentrations of Cd, Pb, Sb, Mn, and As in brown rice were 0.103, 0.131, 5.175, 6.007, and 0.524 mg/kg, respectively. Daily intakes of Cd, As, Sb, Pb, and Mn through brown rice consumption were estimated to be 0.011, 0.0002, 0.004, 0.0001, and 0.0003 mg/(kg/day), respectively. The combined hazard index for the five heavy metals was 22.5917, and the total cancer risk was 0.1773. Cd contributed most significantly to cancer risk, accounting for approximately 99.77% of this risk. The results show that potential noncarcinogenic and carcinogenic health risks exist for local inhabitants and that regular monitoring of pollution to protect human health is urgently required.

  13. Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge.

    Science.gov (United States)

    Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

    2016-01-01

    Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination.

  14. Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge

    Science.gov (United States)

    Placek, Agnieszka; Grobelak, Anna; Kacprzak, Malgorzata

    2016-01-01

    ABSTRACT Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination. PMID:26368503

  15. Assessment of metals contamination and ecological risk in ait Ammar abandoned iron mine soil, Morocco

    Directory of Open Access Journals (Sweden)

    Nouri Mohamed

    2016-03-01

    Full Text Available The present study is an attempt to assess the pollution intensity and corresponding ecological risk of phosphorus and metals including Cd, Cr, Cu, Zn, Pb and Fe using various indices like geo-accumulation index, enrichment factor, pollution and ecological risk index. In all, 20 surface soil samples were collected from the Ait Ammar iron mine of Oued Zem city, province of Khouribga, in central Morocco. The concentrations of heavy metals in soil samples were used to assess their potential ecological risks. According to the results of potential ecological risk index (RI, pollution index (PI, geo-accumulation index (Igeo, enrichment factor (EF, potential contamination index (Cp, contaminant factor (Cf and degree of contamination (Cd, based on the averages, considerable pollution of metals in soils of study area was observed. The consequence of the correlation matrix and principal component analysis (PCA indicated that Fe, Cu, Zn, Cr and P mainly originated from natural sources and Cd and Pb are mostly derived from anthropogenic sources. The results showed that these metals in soil were ranked by severity of ecological risk as Pb > Cd > Cu > Cr > Zn, based on their single-element indexes. In view of the potential ecological risk (RI, soils from all soil samples showed a potential ecological risk. These results will provide basic information for the improvement of soil environment management and heavy metal pollution prevention in Ait Ammar.

  16. Heavy-metal contamination of agricultural soils irrigated with industrial effluents

    International Nuclear Information System (INIS)

    Nabi, G.; Ashraf, M.; Aslam, M. R.

    2001-01-01

    Pakistan is facing a thread of degradation of water and land-resources by industrial effluents. To evaluated the suitability of these effluents as a source of irrigation for agriculture and the study their effects on soil chemical properties, experiments were conducted in the industrial area of Sheikhupura, where effluent from Paper and Board Mill (PBM), Leather Industry (LI) and Fertilizer Industry (FI) were being used for irrigation. At each site, two fields were selected, one irrigated with industrial effluents and the other with tube-well/canal water. The soil samples were collected and analyzed for pH, ECe, SAR and for heavy metals, such as Cu, Cd, Cr, Zn, Pb, Mn, Fe, Al and Ni. Soil receiving effluent from LI showed higher ECe and SAR values, as compared to the soils receiving other effluents. The concentration of Al was high in the soil irrigated with LI effluent. The Mn and Fe contents were higher in soils irrigated with PBM effluent. Effluent from LI is not fit for irrigation, since its recipient soil showed high concentration of Cr and also high sodicity values. Except Cr, the heavy metals were not of environmental concern. (author)

  17. Vulnerability of soil resources to heavy metals contamination in Central Bekaa-Lebanon

    International Nuclear Information System (INIS)

    Darwish, T.; Jomaa, I.; Sukarieh, W.; Chihny, R.

    2000-01-01

    Full text.Changes in land use and urbanization yield more pressure put on limited soil and water resources, including the risk of pollution with toxic heavy metals. The study area lies in the Bekaa valley totaling about 12753 ha. The valley receives from the west torrential fan deposits and a mixture of colluvial and alluvial material. The principal soil classes are Fluvisols, Cambisols, Regosols, Vertisols and Luvisols. The area is populated and also the most important agricultural part of the plain. Agriculture in the plain is being practiced mainly with cash, field crops and vegetables. The western surrounding area is being used mainly for terraced fruit trees. This Arab-German Technical Cooperation Project (ACSAD-BGR) aimed, following the ISO standards and Eikman-Klocke recommendations, at investigating the nature of the extends of soil pollution by heavy metals in two pilot areas: The central Bekaa-Lebanon and Ghouta-Damascus. Different institutions cooperate in the implementation of this project to assess soil and groundwater vulnerability within the context of possible rehabilitation and land use. In the investigation area, possible soil contamination results from human activities such as agriculture, industry, dumping of municipal wastes etc..fertilization and pesticide applications are considered a source of Ni and Cr in the soil. Each kind of activities represents hazard of toxic heavy metals input to the upper, most active part of the soil, where plant roots remove nutrients. For example, the spatial distribution of As and Pb could be associated with leather factory and traffic. However, the higher values of As and Pb distribution, though remaining within the range of the soil multifunctional use, could be linked to the transfer by surface water. In addition, water storage made farmers use non-conventional sources of irrigation water with hazards of contamination of both soil and groundwater resources. Our analyses of water samples taken downstream in

  18. Heavy metals contamination characteristics in soil of different mining activity zones

    Institute of Scientific and Technical Information of China (English)

    LIAO Guo-li; LIAO Da-xue; LI Quan-ming

    2008-01-01

    Depending upon the polluted features of various mining activities in a typical nonferrous metal mine, the contaminated soil area was divided into four zones which were polluted by tailings, mine drainage, dust deposition in wind and spreading minerals during vehicle transportation, respectively. In each zone, soil samples were collected. Total 28 soil samples were dug and analyzed by ICP-AES and other relevant methods. The results indicate that the average contents of Zn, Pb, Cd, Cu and As in soils are 508.6, 384.8, 7.53, 356 and 44.6 mg/kg, respectively. But the contents of heavy metals in different zone have distinct differences. The proportion of oxidizing association with organic substance is small. Difference of the association of heavy metals is small in different polluted zones.

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

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland

    2006-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

  1. Health Risk-Based Assessment and Management of Heavy Metals-Contaminated Soil Sites in Taiwan

    Directory of Open Access Journals (Sweden)

    Zueng-Sang Chen

    2010-10-01

    Full Text Available Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1 food safety risk assessment for brown rice growing in a HMs-contaminated site; (2 a tiered approach to health risk assessment for a contaminated site; (3 risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4 soil remediation cost analysis for contaminated sites in Taiwan.

  2. Metal-contaminated soil remediation by means of paper mill sludges addition: chemical and ecotoxicological evaluation

    International Nuclear Information System (INIS)

    Calace, N.; Campisi, T.; Iacondini, A.; Leoni, M.; Petronio, B.M.; Pietroletti, M.

    2005-01-01

    Metal pollution of soils is a great environmental problem. The major risks due to metal pollution of soil consist of leaching to groundwater and potential toxicity to plants and/or animals. The objective of this study is to evaluate by means of chemical and ecotoxicological approach the effects of paper mill sludge addition on the mobile metal fraction of polluted metal soils. The study was carried out on acidic soil derived from mining activities and thus polluted with heavy metals, and on two paper mill sludges having different chemical features. The results obtained by leaching experiments showed that the addition of a paper mill sludge, consisting mainly of carbonates, silicates and organic matter, to a heavy-metal polluted soil produces a decrease of available metal forms. The carbonate content seems to play a key role in the chemical stabilisation of metals and consequently in a decrease of toxicity of soil. The leached solutions have a non-toxic effect. The mild remediation by addition of sludge has moreover a lasting effect. - Paper mill sludge decreased available metals

  3. The effects of heavy metal contamination on the soil arthropod community of a shooting range

    International Nuclear Information System (INIS)

    Migliorini, Massimo; Pigino, Gaia; Bianchi, Nicola; Bernini, Fabio; Leonzio, Claudio

    2004-01-01

    Soils in clay pigeon shooting ranges can be seriously contaminated by heavy metals. The pellets contained in ammunition are composed of Pb, Sb, Ni, Zn, Mn and Cu. The total concentrations of these metals in soils, and the effects of their increasing levels on the arthropod community were investigated at seven sampling sites in a clay pigeon shooting range and compared with two controls. Research revealed that the spatial distribution of Pb and Sb contamination in the shot-fall area was strongly correlated with the flight path of the pellets. Ordination obtained through Redundance Analysis showed that Collembola, Protura and Diplura were positively correlated with major detected contaminants (Pb, Sb), while Symphyla showed a negative correlation with these pollutants. Determination of the soluble lead fraction in soil, and of its bioaccumulation in the saprophagous Armadillidium sordidum (Isopoda) and the predator Ocypus olens (Coleoptera), showed that a significant portion of metallic Pb from spent pellets is bioavailable in the soil and can be bioaccumulated by edaphic organisms, entering the soil trophic network, but without biomagnification. - Significant relationships were found between lead accumulation in soil from a shooting range and inhabiting arthropod communities

  4. Health Risk-Based Assessment and Management of Heavy Metals-Contaminated Soil Sites in Taiwan

    Science.gov (United States)

    Lai, Hung-Yu; Hseu, Zeng-Yei; Chen, Ting-Chien; Chen, Bo-Ching; Guo, Horng-Yuh; Chen, Zueng-Sang

    2010-01-01

    Risk-based assessment is a way to evaluate the potential hazards of contaminated sites and is based on considering linkages between pollution sources, pathways, and receptors. These linkages can be broken by source reduction, pathway management, and modifying exposure of the receptors. In Taiwan, the Soil and Groundwater Pollution Remediation Act (SGWPR Act) uses one target regulation to evaluate the contamination status of soil and groundwater pollution. More than 600 sites contaminated with heavy metals (HMs) have been remediated and the costs of this process are always high. Besides using soil remediation techniques to remove contaminants from these sites, the selection of possible remediation methods to obtain rapid risk reduction is permissible and of increasing interest. This paper discusses previous soil remediation techniques applied to different sites in Taiwan and also clarified the differences of risk assessment before and after soil remediation obtained by applying different risk assessment models. This paper also includes many case studies on: (1) food safety risk assessment for brown rice growing in a HMs-contaminated site; (2) a tiered approach to health risk assessment for a contaminated site; (3) risk assessment for phytoremediation techniques applied in HMs-contaminated sites; and (4) soil remediation cost analysis for contaminated sites in Taiwan. PMID:21139851

  5. [Heavy Metal Contamination in Farmland Soils at an E-waste Disassembling Site in Qingyuan, Guangdong, South China].

    Science.gov (United States)

    Zhang, Jin-lian; Ding, Jiang-feng; Lu, Gui-ning; Dang, Zhi; Yi, Xiao-yun

    2015-07-01

    Crude e-waste dismantling activities have caused a series of environmental pollution problems, and the pollutants released from the dismantling activities would finally pose high risks to human health by means of the accumulation through food chains. To explore the contamination status of heavy metals to the surrounding farmland soils in Longtang and Shijiao Town, Qingyuan, Guangdong, China, 22 farmland soil samples were collected and analyzed for the contents, spatial distributions and chemical forms of 6 heavy metals (Pb, Cu, Cd, Zn, Cr and Ni). The results showed that the 6 heavy metals exhibited obvious accumulations when compared to the corresponding background values in Guangdong Province. According to farmland environmental quality evaluation standard for edible agricultural products HJ 332-2006, the pollution severity of heavy metals was evaluated by monomial pollution index and Nemerow synthetic pollution index methods, the results indicated that 72. 7% of the soil samples contained one or more kinds of heavy metals with higher concentrations than the corresponding standard values, Cd, Cu, Pb and Zn were the main metals in the polluted soils, and for the proportion of contaminated soil samples in all the 22 samples, Cd was the highest, followed by Cu, and finally Pb and Zn. Nemerow synthetic pollution index further revealed that 68. 2% of soil samples were contaminated, and among them 53. 3% of samples were heavily contaminated. Most of the heavy metals were well correlated with each other at the 0. 05 or 0. 01 level, which indicated that primitive e-waste recycling activities were an important source of the heavy metal contamination in Longtang and Shijiao Town. The contents of Cd, Pb, Cu and Zn in surface soils were higher than those of other soil layers, and the contents of these 4 metals in deep soils (20- 100 cm) did not show significant decreases with the increasing depths. The contents of Cr and Ni maintained constant, and exhibited no statistical

  6. Assessment Of Heavy Metal Contamination Of Arable Soils In Central Bekaa Plain, Lebanon

    International Nuclear Information System (INIS)

    Darwish, T.; Jomaa, I.; Khawlie, M.; Mýýuller, H. W.; Moller, A.

    2004-01-01

    The study area is located in the Bekaa plain of Lebanon totaling about 12753 ha. It lies between the eastern foothills of Mount Lebanon chain and expands across the Litani River towards the foothills of the eastern Anti-Lebanon Mountains. Its characteristics, i.e. natural terrain, climate and socio-economy, make it vulnerable especially due to soil pollution. This paper tries to identify the nature and level of soil pollution by heavy metals. Valley slopes represent a complex landform and lithology that contributed to the formation of different soil. Agriculture in the plain is being practiced mainly with cash, field crops and vegetables. Throughout the central part of the plain, groundwater table is abundant and relatively high (<1.0 m. locally) that multiplies the vulnerability of the soil-groundwater system. There are different sources of pollution, such as industrial (tanneries, batteries, leather manufacturing), solid and liquid wastes, and agricultural due to uncontrolled application of fertilizers, pesticides and insecticides. Meanwhile, no local criteria for land contamination with heavy metals are adapted yet. A total of 131 soil samples from 41 soil profiles were collected from sites representing different soil types and cropping systems. Additionally, five water samples were collected to get tentative idea about the extent of water contamination from surface and groundwater bodies. Soil samples were analyzed for physical and chemical properties and wet digested in aqua regia for the determination of the heavy metal content on the atomic absorption. Results of the total heavy metal content in the soils of the Central Bekaa showed normal values for main metals except Cr and Ni, which showed a relatively high level reaching, according to Eckamn Kloke, 1993-2000 criteria the tolerance level II. This is hazardous in an area of intensive vegetable production designed for fresh consumption. Point sources of pollution are equally found for Pb and Cd. The level

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

    Science.gov (United States)

    Farrell, Mark; Jones, Davey L

    2010-03-15

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

  8. Soil heavy metal contamination and health risks associated with artisanal gold mining in Tongguan, Shaanxi, China.

    Science.gov (United States)

    Xiao, Ran; Wang, Shuang; Li, Ronghua; Wang, Jim J; Zhang, Zengqiang

    2017-07-01

    Soil contamination with heavy metals due to mining activities poses risks to ecological safety and human well-being. Limited studies have investigated heavy metal pollution due to artisanal mining. The present study focused on soil contamination and the health risk in villages in China with historical artisanal mining activities. Heavy metal levels in soils, tailings, cereal and vegetable crops were analyzed and health risk assessed. Additionally, a botany investigation was conducted to identify potential plants for further phytoremediation. The results showed that soils were highly contaminated by residual tailings and previous mining activities. Hg and Cd were the main pollutants in soils. The Hg and Pb concentrations in grains and some vegetables exceeded tolerance limits. Moreover, heavy metal contents in wheat grains were higher than those in maize grains, and leafy vegetables had high concentrations of metals. Ingestion of local grain-based food was the main sources of Hg, Cd, and Pb intake. Local residents had high chronic risks due to the intake of Hg and Pb, while their carcinogenic risk associated with Cd through inhalation was low. Three plants (Erigeron canadensis L., Digitaria ciliaris (Retz.) Koel., and Solanum nigrum L.) were identified as suitable species for phytoremediation. Copyright © 2017. Published by Elsevier Inc.

  9. Molecular diversity of arbuscular mycorrhizal fungi in relation to soil chemical properties and heavy metal contamination

    International Nuclear Information System (INIS)

    Zarei, Mehdi; Hempel, Stefan; Wubet, Tesfaye; Schaefer, Tina; Savaghebi, Gholamreza; Jouzani, Gholamreza Salehi; Nekouei, Mojtaba Khayam; Buscot, Francois

    2010-01-01

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) associated with dominant plant species were studied along a transect from highly lead (Pb) and zinc (Zn) polluted to non-polluted soil at the Anguran open pit mine in Iran. Using an established primer set for AMF in the internal transcribed spacer (ITS) region of rDNA, nine different AMF sequence types were distinguished after phylogenetic analyses, showing remarkable differences in their distribution patterns along the transect. With decreasing Pb and Zn concentration, the number of AMF sequence types increased, however one sequence type was only found in the highly contaminated area. Multivariate statistical analysis revealed that further factors than HM soil concentration affect the AMF community at contaminated sites. Specifically, the soils' calcium carbonate equivalent and available P proved to be of importance, which illustrates that field studies on AMF distribution should also consider important environmental factors and their possible interactions. - The molecular diversity of AMF was found to be influenced by a combination of soil heavy metal and other soil chemical parameters.

  10. Comparative evaluation of phytoremediation of metal contaminated soil of firing range by four different plant species

    Directory of Open Access Journals (Sweden)

    Saadia R. Tariq

    2016-11-01

    Full Text Available The phytoremediation potential of Helianthus annuus, Zea maize, Brassica campestris and Pisum sativum was studied for the soil of firing range contaminated with selected metals i.e. Cd, Cu, Co, Ni, Cr and Pb. The seedlings of the selected plants germinated in a mixture of sand and alluvial soil were transferred to the pots containing the soil of firing ranges and allowed to grow to the stage of reproductive growth. Subsequently they were harvested and then analyzed for selected metals by using AAS. Among the studied plants, P. sativum exhibited highest removal efficiency (i.e. 96.23% and bioconcentration factor for Pb thereby evidencing it to be Pb hyperaccumulator from the soil of firing ranges. Z. maize appreciably reduced the levels of all the selected metals in the soil but the highest phytoextraction capacity was shown for Pb i.e. 66.36%, which was enhanced to approximately 74% on EDTA application. H. annuus represented the highest removal potential for Cd i.e. 56.03% which was further increased on EDTA application. Thus it proved to be an accumulator of Cd after EDTA application. It was therefore concluded that different plants possess different phytoremediation potentials under given set of conditions.

  11. Molecular diversity of arbuscular mycorrhizal fungi in relation to soil chemical properties and heavy metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Zarei, Mehdi [Department of Soil Science, College of Agriculture, University of Shiraz, Shiraz (Iran, Islamic Republic of); Hempel, Stefan, E-mail: hempel.stefan@googlemail.co [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Freie Universitaet Berlin, Institut fuer Biologie, Okologie der Pflanzen, Altensteinstrasse 6, 14195 Berlin (Germany); Wubet, Tesfaye; Schaefer, Tina [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Savaghebi, Gholamreza [Department of Soil Science Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj (Iran, Islamic Republic of); Jouzani, Gholamreza Salehi; Nekouei, Mojtaba Khayam [Agricultural Biotechnology Research Institute of Iran (ABRII), P.O. Box 31535-1897, Karaj (Iran, Islamic Republic of); Buscot, Francois [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany)

    2010-08-15

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) associated with dominant plant species were studied along a transect from highly lead (Pb) and zinc (Zn) polluted to non-polluted soil at the Anguran open pit mine in Iran. Using an established primer set for AMF in the internal transcribed spacer (ITS) region of rDNA, nine different AMF sequence types were distinguished after phylogenetic analyses, showing remarkable differences in their distribution patterns along the transect. With decreasing Pb and Zn concentration, the number of AMF sequence types increased, however one sequence type was only found in the highly contaminated area. Multivariate statistical analysis revealed that further factors than HM soil concentration affect the AMF community at contaminated sites. Specifically, the soils' calcium carbonate equivalent and available P proved to be of importance, which illustrates that field studies on AMF distribution should also consider important environmental factors and their possible interactions. - The molecular diversity of AMF was found to be influenced by a combination of soil heavy metal and other soil chemical parameters.

  12. Assessment of Metalloid and Metal Contamination in Soils from Hainan, China

    Directory of Open Access Journals (Sweden)

    Xiangjun Liao

    2018-03-01

    Full Text Available The characterization of the concentrations and sources of metals and metalloids in soils is necessary to establish quality standards on a regional level and to assess the potential threat of metals to food safety and human health. A total of 8713 soil samples throughout Hainan Island, China were collected at a density of one sample per 4 km2, and concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn were analyzed. The geometric mean values of the elements were 2.17, 0.60, 26.5, 9.43, 0.033, 8.74, 22.2, 0.26, and 39.6 mg·· kg−1 for As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn, respectively, significantly lower than the background values of Chinese soils with the exception of Se. Principal component analysis (PCA suggested that multiple anthropogenic sources regulated the elemental compositions of the Hainan environment. Coal combustion and mining are important anthropogenic sources of metals for Hainan. The geochemical maps of elements in Hainan soils were produced using the Geographic Information System (GIS method, and several hot-spot areas were identified. The ecological impact of As, Cd, Cu, Cr, Hg, Pb, Ni, and Zn pollution to the soils was extremely “low”.

  13. Heavy metal contamination in soils and vegetables near an e-waste processing site, South China.

    Science.gov (United States)

    Luo, Chunling; Liu, Chuanping; Wang, Yan; Liu, Xiang; Li, Fangbai; Zhang, Gan; Li, Xiangdong

    2011-02-15

    Environmental pollution due to uncontrolled e-waste recycling activities has been reported in a number of locations of China. In the present study, metal pollution to the surrounding environment from a primitive e-waste processing facility was investigated. Soils at sites where e-waste is burned in the open air, those of surrounding paddy fields and vegetable gardens, as well as common vegetable samples were collected and analyzed for heavy metals. The results showed that the soils of former incineration sites had the highest concentrations of Cd, Cu, Pb, and Zn with mean values of 17.1, 11,140, 4500, and 3690 mg kg(-1), respectively. The soils of nearby paddy fields and vegetable gardens also had relatively high concentrations of Cd and Cu. In the edible tissues of vegetables, the concentrations of Cd and Pb in most samples exceeded the maximum level permitted for food in China. Sequential leaching tests revealed that the Cu, Pb, and Zn were predominantly associated with the residual fraction, followed by the carbonate/specifically adsorbed phases with the exception of Cd, which was mainly in the extractable form in paddy fields and vegetable soils. The data showed that uncontrolled e-waste processing operations caused serious pollution to local soils and vegetables. The cleaning up of former incineration sites should be a priority in any future remediation program. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2010-05-01

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  16. Molecular diversity of arbuscular mycorrhizal fungi in relation to soil chemical properties and heavy metal contamination.

    Science.gov (United States)

    Zarei, Mehdi; Hempel, Stefan; Wubet, Tesfaye; Schäfer, Tina; Savaghebi, Gholamreza; Jouzani, Gholamreza Salehi; Nekouei, Mojtaba Khayam; Buscot, François

    2010-08-01

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) associated with dominant plant species were studied along a transect from highly lead (Pb) and zinc (Zn) polluted to non-polluted soil at the Anguran open pit mine in Iran. Using an established primer set for AMF in the internal transcribed spacer (ITS) region of rDNA, nine different AMF sequence types were distinguished after phylogenetic analyses, showing remarkable differences in their distribution patterns along the transect. With decreasing Pb and Zn concentration, the number of AMF sequence types increased, however one sequence type was only found in the highly contaminated area. Multivariate statistical analysis revealed that further factors than HM soil concentration affect the AMF community at contaminated sites. Specifically, the soils' calcium carbonate equivalent and available P proved to be of importance, which illustrates that field studies on AMF distribution should also consider important environmental factors and their possible interactions. Copyright 2010 Elsevier Ltd. All rights reserved.

  17. Effect of soil metal contamination on glyphosate mineralization: role of zinc in the mineralization rates of two copper-spiked mineral soils.

    Science.gov (United States)

    Kim, Bojeong; Kim, Young Sik; Kim, Bo Min; Hay, Anthony G; McBride, Murray B

    2011-03-01

    A systematic investigation into lowered degradation rates of glyphosate in metal-contaminated soils was performed by measuring mineralization of [(14)C]glyphosate to (14)CO(2) in two mineral soils that had been spiked with Cu and/or Zn at various loadings. Cumulative (14)CO(2) release was estimated to be approximately 6% or less of the amount of [(14)C]glyphosate originally added in both soils over an 80-d incubation. For all but the highest Cu treatments (400 mg kg(-1)) in the coarse-textured Arkport soil, mineralization began without a lag phase and declined over time. No inhibition of mineralization was observed for Zn up to 400 mg kg(-1) in either soil, suggesting differential sensitivity of glyphosate mineralization to the types of metal and soil. Interestingly, Zn appeared to alleviate high-Cu inhibition of mineralization in the Arkport soil. The protective role of Zn against Cu toxicity was also observed in the pure culture study with Pseudomonas aeruginosa, suggesting that increased mineralization rates in high Cu soil with Zn additions might have been due to alleviation of cellular toxicity by Zn rather than a mineralization specific mechanism. Extensive use of glyphosate combined with its reduced degradation in Cu-contaminated, coarse-textured soils may increase glyphosate persistence in soil and consequently facilitate Cu and glyphosate mobilization in the soil environment. Copyright © 2010 SETAC.

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

    Science.gov (United States)

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

    2014-09-01

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

  19. Heavy metal contamination and ecological risk of farmland soils adjoining steel plants in Tangshan, Hebei, China.

    Science.gov (United States)

    Yang, Liyun; Yang, Maomao; Wang, Liping; Peng, Fei; Li, Yuan; Bai, Hao

    2018-01-01

    The purpose of this study was to determine the heavy metal concentrations and ecological risks to farmland soils caused by atmospheric deposition adjoining five industrial steel districts in Tangshan, Hebei, China. A total of 39 topsoil samples from adjoining these plants were collected and analyzed for Pb, Zn, Cu, Cr, and As. The geo-accumulation index (Igeo) and potential ecological risk index (PERI) were calculated to assess the heavy metal pollution level in soils. The results showed that the levels of Pb and As in farmland soils adjoining all steel plants were more than the background value, with the As content being excessively high. The Cr and Cu contents of some samples were over the background values, but the Zn content was not. In all the research areas, the largest Igeo value of the heavy metals was for As, followed by Pb, and the largest monomial PERI ([Formula: see text]) was As, which showed that the pollution of As in farmland soils was significant and had considerable ecological risk. Additionally, the heavy metal sequential extraction experiments showed that Pb and Cr, which exceeded the background value, were present in about 20% of the exchangeable and carbonate-bound fractions in the soils surrounding some steel plants. This would imply the risk of these heavy metals being absorbed and accumulated by the crops. Therefore, the local government needs to control the pollution of heavy metals in the farmland soils adjoining the steel plant as soon as possible, in order to avoid possible ecological and food safety risks.

  20. 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)

  1. Trace metal contaminants in sediments and soils: comparison between ICP and XRF quantitative determination

    Directory of Open Access Journals (Sweden)

    Congiu A.

    2013-04-01

    Full Text Available A mineralization method HCl-free for heavy metals analysis in sediments and soils by DRC-ICP-MS was developed. The procedure, which uses concentrated nitric, hydrofluoric acid and hydrogen peroxide, was applied for the analysis of arsenic, cadmium, chromium, nickel and vanadium. The same samples were then analyzed, as pressed pellets, by wavelength dispersive X ray fluorescence (WD-XRF using the dedicated PANalytical Pro Trace solution for the determination of trace elements. Comparison of ICP and XRF data showed good agreement for the elements under investigation, unless for chromium in soils, which recovery was not complete.

  2. Toxicokinetics of Zn and Cd in the earthworm Eisenia andrei exposed to metal-contaminated soils under different combinations of air temperature and soil moisture content.

    Science.gov (United States)

    González-Alcaraz, M Nazaret; Loureiro, Susana; van Gestel, Cornelis A M

    2018-04-01

    This study evaluated how different combinations of air temperature (20 °C and 25 °C) and soil moisture content (50% and 30% of the soil water holding capacity, WHC), reflecting realistic climate change scenarios, affect the bioaccumulation kinetics of Zn and Cd in the earthworm Eisenia andrei. Earthworms were exposed for 21 d to two metal-contaminated soils (uptake phase), followed by 21 d incubation in non-contaminated soil (elimination phase). Body Zn and Cd concentrations were checked in time and metal uptake (k 1 ) and elimination (k 2 ) rate constants determined; metal bioaccumulation factor (BAF) was calculated as k 1 /k 2 . Earthworms showed extremely fast uptake and elimination of Zn, regardless of the exposure level. Climate conditions had no major impacts on the bioaccumulation kinetics of Zn, although a tendency towards lower k 1 and k 2 values was observed at 25 °C + 30% WHC. Earthworm Cd concentrations gradually increased with time upon exposure to metal-contaminated soils, especially at 50% WHC, and remained constant or slowly decreased following transfer to non-contaminated soil. Different combinations of air temperature and soil moisture content changed the bioaccumulation kinetics of Cd, leading to higher k 1 and k 2 values for earthworms incubated at 25 °C + 50% WHC and slower Cd kinetics at 25 °C + 30% WHC. This resulted in greater BAFs for Cd at warmer and drier environments which could imply higher toxicity risks but also of transfer of Cd within the food chain under the current global warming perspective. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Cost–benefit calculation of phytoremediation technology for heavy-metal-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Xiaoming; Lei, Mei, E-mail: leim@igsnrr.ac.cn; Chen, Tongbin

    2016-09-01

    Heavy-metal pollution of soil is a serious issue worldwide, particularly in China. Soil remediation is one of the most difficult management issues for municipal and state agencies because of its high cost. A two-year phytoremediation project for soil contaminated with arsenic, cadmium, and lead was implemented to determine the essential parameters for soil remediation. Results showed highly efficient heavy metal removal. Costs and benefits of this project were calculated. The total cost of phytoremediation was US$75,375.2/hm{sup 2} or US$37.7/m{sup 3}, with initial capital and operational costs accounting for 46.02% and 53.98%, respectively. The costs of infrastructures (i.e., roads, bridges, and culverts) and fertilizer were the highest, mainly because of slow economic development and serious contamination. The cost of phytoremediation was lower than the reported values of other remediation technologies. Improving the mechanization level of phytoremediation and accurately predicting or preventing unforeseen situations were suggested for further cost reduction. Considering the loss caused by environmental pollution, the benefits of phytoremediation will offset the project costs in less than seven years. - Highlights: • A two-year phytoremediation project was introduced. • Costs and benefits of a phytoremediation project were calculated. • Costs of phytoremediation project can be offset by benefits in 7 years.

  4. Cost–benefit calculation of phytoremediation technology for heavy-metal-contaminated soil

    International Nuclear Information System (INIS)

    Wan, Xiaoming; Lei, Mei; Chen, Tongbin

    2016-01-01

    Heavy-metal pollution of soil is a serious issue worldwide, particularly in China. Soil remediation is one of the most difficult management issues for municipal and state agencies because of its high cost. A two-year phytoremediation project for soil contaminated with arsenic, cadmium, and lead was implemented to determine the essential parameters for soil remediation. Results showed highly efficient heavy metal removal. Costs and benefits of this project were calculated. The total cost of phytoremediation was US$75,375.2/hm"2 or US$37.7/m"3, with initial capital and operational costs accounting for 46.02% and 53.98%, respectively. The costs of infrastructures (i.e., roads, bridges, and culverts) and fertilizer were the highest, mainly because of slow economic development and serious contamination. The cost of phytoremediation was lower than the reported values of other remediation technologies. Improving the mechanization level of phytoremediation and accurately predicting or preventing unforeseen situations were suggested for further cost reduction. Considering the loss caused by environmental pollution, the benefits of phytoremediation will offset the project costs in less than seven years. - Highlights: • A two-year phytoremediation project was introduced. • Costs and benefits of a phytoremediation project were calculated. • Costs of phytoremediation project can be offset by benefits in 7 years.

  5. Phytoextraction with Brassica napus L.: A tool for sustainable management of heavy metal contaminated soils.

    NARCIS (Netherlands)

    Grispen, V.M.J.; Nelissen, H.J.M.; Verkleij, J.A.C.

    2006-01-01

    Phytoextraction is a promising tool to extract metals from contaminated soils and Brassica napus L. seems to be a possible candidate species for this purpose. To select accessions with the ability to accumulate cadmium, hydroponically grown 21 day old seedlings of 77 B. napus L. accessions were

  6. Cost-benefit calculation of phytoremediation technology for heavy-metal-contaminated soil.

    Science.gov (United States)

    Wan, Xiaoming; Lei, Mei; Chen, Tongbin

    2016-09-01

    Heavy-metal pollution of soil is a serious issue worldwide, particularly in China. Soil remediation is one of the most difficult management issues for municipal and state agencies because of its high cost. A two-year phytoremediation project for soil contaminated with arsenic, cadmium, and lead was implemented to determine the essential parameters for soil remediation. Results showed highly efficient heavy metal removal. Costs and benefits of this project were calculated. The total cost of phytoremediation was US$75,375.2/hm(2) or US$37.7/m(3), with initial capital and operational costs accounting for 46.02% and 53.98%, respectively. The costs of infrastructures (i.e., roads, bridges, and culverts) and fertilizer were the highest, mainly because of slow economic development and serious contamination. The cost of phytoremediation was lower than the reported values of other remediation technologies. Improving the mechanization level of phytoremediation and accurately predicting or preventing unforeseen situations were suggested for further cost reduction. Considering the loss caused by environmental pollution, the benefits of phytoremediation will offset the project costs in less than seven years. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Potentially toxic metal contamination of urban soils and roadside dust in Shanghai, China

    International Nuclear Information System (INIS)

    Shi Guitao; Chen Zhenlou; Xu Shiyuan; Zhang Ju; Wang Li; Bi Chunjuan; Teng Jiyan

    2008-01-01

    A detailed investigation was conducted to understand the contamination characteristics of a selected set of potentially toxic metals in Shanghai. The amount of Pb, Zn, Cu, Cr, Cd and Ni were determined from 273 soil/dust samples collected within urban area. The results indicated that concentration of all metals except Ni in soils was significant, and metal pollution was even severer in roadside dust. A series of metal spatial distribution maps were created through geostatistical analysis, and the pollution hotspots tended to associate with city core area, major road junctions, and the regions close to industrial zones. In attempt of identifying the source of metals through geostatistical and multivariate statistical analyses, it was concluded as follows: Pb, Zn and Cu mainly originated from traffic contaminants; soil Ni was associated with natural concentration; Cd largely came from point-sourced industrial pollution; and Cr, Ni in dust were mainly related to atmospheric deposition. - Human activities have led to high accumulation of potentially toxic metals in urban soils and roadside dust of Shanghai

  8. Potentially toxic metal contamination of urban soils and roadside dust in Shanghai, China

    Energy Technology Data Exchange (ETDEWEB)

    Shi Guitao [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Chen Zhenlou [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China)], E-mail: gt_shi@163.com; Xu Shiyuan [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Zhang Ju [School of Environment and Planning, Liaocheng University, Liaocheng 252059 (China); Wang Li; Bi Chunjuan [Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200062 (China); Teng Jiyan [Shanghai Chongming Dongtan National Nature Reserve, Shanghai 202183 (China)

    2008-11-15

    A detailed investigation was conducted to understand the contamination characteristics of a selected set of potentially toxic metals in Shanghai. The amount of Pb, Zn, Cu, Cr, Cd and Ni were determined from 273 soil/dust samples collected within urban area. The results indicated that concentration of all metals except Ni in soils was significant, and metal pollution was even severer in roadside dust. A series of metal spatial distribution maps were created through geostatistical analysis, and the pollution hotspots tended to associate with city core area, major road junctions, and the regions close to industrial zones. In attempt of identifying the source of metals through geostatistical and multivariate statistical analyses, it was concluded as follows: Pb, Zn and Cu mainly originated from traffic contaminants; soil Ni was associated with natural concentration; Cd largely came from point-sourced industrial pollution; and Cr, Ni in dust were mainly related to atmospheric deposition. - Human activities have led to high accumulation of potentially toxic metals in urban soils and roadside dust of Shanghai.

  9. Heavy metals contamination of soils in response to wastewater irrigation in Rawalpindi region

    International Nuclear Information System (INIS)

    Mushtaq, N.; Khan, K.S.

    2010-01-01

    The study was conducted to evaluate the quality of effluents/ waste water samples from Rawalpindi region for irrigation purpose and to elucidate effects of their application on heavy metal contents in soils of area. Results indicated that the EC, SAR, RSC and TDS of most effluent/ waste water samples were above the critical limits. Cadmium and Cr were above the critical limits in almost all the effluent samples, whereas Ni was high in 14, Pb was high in 10, Cu was high in 5 and the Fe was high in 3 effluent samples as compared to critical limits. Regarding heavy metals contents of soils irrigated by these effluents/ waste water, total Fe, total Cd and total Ni were higher in almost all the sampled sites, whereas total Cr was high at 7 sampled sites. AB-DTPA extractable Fe and Zn were higher at all the sampled sites, while the extractable Cd was higher at 2 sampled sites. Overall, the effluent samples collected from Adiala showed high concentrations of heavy metals, whereas soils of Wah factory and Islamabad area had higher heavy metal contents (total and AB-DTPA extractable). On the basis of results it is concluded that quality of effluents/ waste water samples collected from different locations of Rawalpindi is not good for irrigation and the long term use of these effluents for crop production caused accumulation of some toxic metals in soils above critical limits which is harmful for soil health and may lead to elevated levels of heavy metals in crop plants. (author)

  10. The Effect of Heavy Metal Contaminated Soil on Growth and Development of Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Żurek G.

    2013-04-01

    Full Text Available Contamination of agricultural land in Poland by heavy metals is not a general problem but is limited to industrial areas. In regions of long history of industrial emission, of elevated levels of lead, cadmium, zinc and other ions during coal and ore mining and processing, as for example in Silesia, about 10 % of agricultural land may be characterized by exceeded maximum residue limits for Cd, Pb, Cu, Ni and Zn ions. Since the maintenance of agricultural areas in those regions is important from an ecological standpoint, the alternative farming activities are needed. Perennial grass biomass production for energy purposes is currently the best solution for majority of agricultural areas not suitable for food production in Poland. Along with increasing knowledge on separation and utilization of heavy metals (HM during and after biomass processing, phytoremediation of polluted soils will become important and valuable. To detect the effect of soil HM ions concentration on growth and development of selected, tall growing and high biomass yielding perennial grass cultivars, the chlorophyll fluorescence parameters were registered. The elevated content of Pb, Cd and Zn ions in soil influenced on decrease of: minimal (Fo, maximal (Fm and variable (Fv fluorescence level as well as on total complementary area on a diagram of chlorophyll a fluorescence induction curve (Area. Based on detected parameters it was concluded, that the high level of HM ions in soils negatively affected the efficiency of photosynthesis. Therefore, plant growth, as well as development of generative shoots and finally the biomass yield were reduced in some cultivars. Among tested cultivars different reaction for HM ions in polluted soil were noted: from only slightly modified parameters of photosynthesis and unreduced yield (Elytrigia elongata cv. Bamar and Arrhenatherum elatius cv. Wiwena to significantly reduced Fo, Fv, Fm and biomass yield (Bromus carinathus cv. Broma and Bromus

  11. A multi-technique phytoremediation approach to purify metals contaminated soil from e-waste recycling site.

    Science.gov (United States)

    Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Sophie Gu, Xiaowen

    2017-12-15

    Multiple techniques for soil decontamination were combined to enhance the phytoremediation efficiency of Eucalyptus globulese and alleviate the corresponding environmental risks. The approach constituted of chelating agent using, electrokinetic remediation, plant hormone foliar application and phytoremediation was designed to remediate multi-metal contaminated soils from a notorious e-waste recycling town. The decontamination ability of E. globulese increased from 1.35, 58.47 and 119.18 mg per plant for Cd, Pb and Cu in planting controls to 7.57, 198.68 and 174.34 mg per plant in individual EDTA treatments, respectively, but simultaneously, 0.9-11.5 times more metals leached from chelator treatments relative to controls. Low (2 V) and moderate (4 V) voltage electric fields provoked the growth of the species while high voltage (10 V) had an opposite effect and metal concentrations of the plants elevated with the increment of voltage. Volumes of the leachate decreased from 1224 to 134 mL with voltage increasing from 0 to 10 V due to electroosmosis and electrolysis. Comparing with individual phytoremediation, foliar cytokinin treatments produced 56% more biomass and intercepted 2.5 times more leachate attributed to the enhanced transpiration rate. The synergistic combination of the individuals resulted in the most biomass production and metal accumulation of the species under the stress condition relative to other methods. Time required for the multi-technique approach to decontaminate Cd, Pb and Cu from soil was 2.1-10.4 times less than individual chelator addition, electric field application or plant hormone utilization. It's especially important that nearly no leachate (60 mL in total) was collected from the multi-technique system. This approach is a suitable method to remediate metal polluted site considering its decontamination efficiency and associated environmental negligible risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-04-01

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

  13. 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

  14. Determination of heavy metals contamination of trees and soils due vehicular emission in Karachi city

    International Nuclear Information System (INIS)

    Ara, F.; Iqbal, M.Z.; Qureshi, M.S.

    1996-01-01

    The concentration of Cu, Fe, Ni, and Pb in Eucalyptus sp. and Ficus religiosa leaves were at highest at those sites where the traffic density was highest, but the level of Zn in Eucalyptus sp. was highest at the other site. Cr was not detected in both the species in any area, while Cd was fund only in samples of Eucalyptus sp. Other site is comparatively less polluted area, therefore the level of these metals in leaves of above mentioned trees were low. The levels of above metals in soil were low as compared to leaves samples. Cu was highest at the site where the traffic is highest and lowest at other site, while level of P was highest in heavily traffic area and lowest at comparatively less traffic site soil samples. Zn showed significant results, highest concentration was detected at the highly polluted areas. (orig/A.B.)

  15. [Evaluation of compounding EDTA and citric acid on remediation of heavy metals contaminated soil].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Cai, Wen-Min

    2014-08-01

    As commonly used eluents, Na2EDTA (EDTA) and citric acid (CA) have been widely applied in remediation of soil contaminated by heavy metals. In order to evaluate the removal of arsenic, cadmium, copper, and lead in the contaminated soil collected in a chemical plant by compounding EDTA and CA, a series of stirring experiments were conducted. Furthermore, the changes in speciation distribution of heavy metals before and after washing were studied. The results showed that, adopting the optimal molar ratio of EDTA/CA (1:1), when the pH of the solution was 3, the stirring time was 30 min, the stirring rate was 150 r x min(-1) and the L/S was 5:1, the removal rates of arsenic, cadmium, copper and lead could reach 11.72%, 43.39%, 24.36% and 27.17%, respectively. And it was found that after washing, for arsenic and copper, the content of acid dissolved fraction rose which increased the percentage of available contents. Fe-Mn oxide fraction mainly contributed to the removal of copper. As for cadmium, the percentages of acid dissolved fraction, Fe-Mn oxide fraction and organic fraction also decreased. In practical projects, speciation changes would pose certain environmental risk after soil washing, which should be taken into consideration.

  16. Performance of bioaugmentation-assisted phytoextraction applied to metal contaminated soils: A review

    International Nuclear Information System (INIS)

    Lebeau, Thierry; Braud, Armelle; Jezequel, Karine

    2008-01-01

    Bioaugmentation-assisted phytoextraction is a promising method for the cleaning-up of soils contaminated by metals. Bacteria mainly Plant Growth Promoting Rhizobacteria (PGPR) and fungi mainly Arbuscular Mycorrhizal Fungi (AMF) associated with hyperaccumulating or non-hyperaccumulating plants were analyzed on the basis of a bioprocess engineering approach (concentration and amount of metals extracted by plants, translocation and bioconcentration factor, and plant biomass). In average bioaugmentation increased metals accumulated by shoots by a factor of about 2 (metal concentration) and 5 (amount) without any obvious differences between bacteria and fungi. To optimize this process, new relevant microorganism-plant associations and field scale experiments are needed along with a common methodology for the comparison of all experiments on the same basis. Recommendations were suggested concerning both the microbial-plant selection and the implementation of bioaugmentation to enhance the microbial survival. The use of microbial consortia associated with plant was discussed notably for multi-contaminated soils. - Bioaugmentation-assisted plant improves the phytoextraction performances for soils contaminated by metals

  17. Remediation of heavy-metal-contaminated soil using chelant extraction: Feasibility studies

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W.; Miller, G.; Taylor, J.D.; Schneider, J.F.; Zellmer, S.; Edgar, D.E.; Johnson, D.O.

    1993-08-01

    Results are presented of a laboratory investigation conducted to determine the efficacy of using chelating agents to extract heavy metals (Pb, Cd, Cr, Ba, Cu, and Zn) from soil, the primary focus being on the extraction of lead from the soil. Results from the batch-shaker studies and emphasizes the columnar extraction studies are described. The chelating agents studied included ethylenediaminetetraacetic acid (EDTA) and citric acid, in addition to water. Concentrations of the chelants ranged from 0.01 to 0.05 M; the suspension pH was varied between 3 and 8. Results showed that the removal of lead using citric acid and water was somewhat pH-dependent. For the batch-shaker studies, the results indicated that EDTA was more effective at removing Cd, Cu, Pb, and Zn than was citric acid (both present at 0.01 M). EDTA and citric acid were equally effective in mobilizing Cr and Ba from the soil. Heavy metals removal was slightly more effective in the more acidic region (pH {le} 5).

  18. Spectroscopic analysis of soil metal contamination around a derelict mine site in the Blue Mountains, Australia

    Science.gov (United States)

    Shamsoddini, A.; Raval, S.; Taplin, R.

    2014-09-01

    Abandoned mine sites pose the potential threat of the heavy metal pollution spread through streams and via runoff leading to contamination of soil and water in their surrounding areas. Regular monitoring of these areas is critical to minimise impacts on water resources, flora and fauna. Conventional ground based monitoring is expensive and sometimes impractical; spectroscopic methods have been emerged as a reliable alternative for this purpose. In this study, the capabilities of the spectroscopy method were examined for modelling soil contamination from around the abandoned silver-zinc mine located at Yerranderie, NSW Australia. The diagnostic characteristics of the original reflectance data were compared with models derived from first and second derivatives of the reflectance data. The results indicate that the models derived from the first derivative of the reflectance data estimate heavy metals significantly more accurately than model derived from the original reflectance. It was also found in this study that there is no need to use second derivative for modelling heavy metal soil contamination. Finally, the results indicate that estimates were of greater accuracy for arsenic and lead compared to other heavy metals, while the estimation for silver was found to be the most erroneous.

  19. Performance of bioaugmentation-assisted phytoextraction applied to metal contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Lebeau, Thierry [Equipe Depollution Biologique des Sols (EDBS), University of Haute-Alsace, 28, rue de Herrlisheim, BP 50 568, 68 008 Colmar Cedex (France)], E-mail: thierry.lebeau@uha.fr; Braud, Armelle; Jezequel, Karine [Equipe Depollution Biologique des Sols (EDBS), University of Haute-Alsace, 28, rue de Herrlisheim, BP 50 568, 68 008 Colmar Cedex (France)

    2008-06-15

    Bioaugmentation-assisted phytoextraction is a promising method for the cleaning-up of soils contaminated by metals. Bacteria mainly Plant Growth Promoting Rhizobacteria (PGPR) and fungi mainly Arbuscular Mycorrhizal Fungi (AMF) associated with hyperaccumulating or non-hyperaccumulating plants were analyzed on the basis of a bioprocess engineering approach (concentration and amount of metals extracted by plants, translocation and bioconcentration factor, and plant biomass). In average bioaugmentation increased metals accumulated by shoots by a factor of about 2 (metal concentration) and 5 (amount) without any obvious differences between bacteria and fungi. To optimize this process, new relevant microorganism-plant associations and field scale experiments are needed along with a common methodology for the comparison of all experiments on the same basis. Recommendations were suggested concerning both the microbial-plant selection and the implementation of bioaugmentation to enhance the microbial survival. The use of microbial consortia associated with plant was discussed notably for multi-contaminated soils. - Bioaugmentation-assisted plant improves the phytoextraction performances for soils contaminated by metals.

  20. Environmental hazards related to Miscanthus x giganteus cultivation on heavy metal contaminated soil

    Directory of Open Access Journals (Sweden)

    Pogrzeba M.

    2013-04-01

    Full Text Available According to recent estimates reaching the target of a 20% share of renewable energy sources (RES in the final energy balance in Poland by 2020 will result in the demand for more than 8 million tons of biomass, which, in turn, will entail the necessity of creating large-scale energy crop plantations. According to EU assumptions the most effective way to produce biomass for energy purposes is cultivation of energy crops in agricultural areas. It is particularly vital for Poland, because these areas constitute a relatively large part of the country (59%, 76% of them being used as farmlands. In Silesia, the most industrialized region of the country, 5-10% of agricultural soils are contaminated with cadmium, lead and zinc. The main objective of the presented study was to estimate the accumulation of heavy metals in the tissues of Miscanthus x giganteus grown on contaminated soils and calculate concentrations of Pb, Cd and Zn in crops. It was shown that the large intake of heavy metals by that species could cause high emissions of pollutants into the atmosphere during its improper combustion. As a side effect, winter harvesting led to the loss of even 30% of biomass. Plant residues (leaves can be the source of pollution after decomposing and releasing metals back into the soil. Moreover, miscanthus leaves can be transferred by wind to the surrounding areas. It is very likely that ash coming from the combustion of contaminated biomass cannot be used as a fertilizer.

  1. Utilization of fly ash for stabilization/solidification of heavy metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Dermatas, D.; Meng, X. [Stevens Inst. of Technology, Hoboken, NJ (United States)

    1995-12-01

    Pozzolanic-based stabilization/solidification (S/S) is an effective, yet economic technological alternative to immobilize heavy metals in contaminated soils and sludges. Fly ash waste materials were used along with quicklime (CaO) to immobilize lead, trivalent and hexavalent chromium present in contaminated clayey sand soils. The degree of heavy metal immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as controlled extraction experiments. These leaching test results along with X-ray diffraction (XRD), scanning electron microscope and energy dispersive x-ray (SEM-EDX) analyses were also implemented to elucidate the mechanisms responsible for immobilization of the heavy metals under study. Finally, the reusability of the stabilized waste forms in construction applications was also investigated by performing unconfined compressive strength and swell tests. Results suggest that the controlling mechanism for both lead and hexavalent chromium immobilization is surface adsorption, whereas for trivalent chromium it is hydroxide precipitation. Addition of fly ash to the contaminated soils effectively reduced heavy metal leachability well below the non-hazardous regulatory limits. However, quicklime addition was necessary in order to attain satisfactory immobilization levels. Overall, fly ash addition increases the immobilization pH region for all heavy metals tested, and significantly improves the stress-strain properties of the treated solids, thus allowing their reuse as readily available construction materials. The only potential problem associated with this quicklime/fly ash treatment is the excessive formation of the pozzolanic product ettringite in the presence of sulfates. Ettringite, when brought in contact with water, may cause significant swelling and subsequent deterioration of the stabilized matrix. Addition of minimum amounts of barium hydroxide was shown to effectively eliminate ettringite formation.

  2. [Enhanced phytoextraction of heavy metal contaminated soil by chelating agents and auxin indole-3-acetic acid].

    Science.gov (United States)

    Zhou, Jian-min; Dang, Zhi; Chen, Neng-chang; Xu, Sheng-guang; Xie, Zhi-yi

    2007-09-01

    The environmental risk of chelating agents such as EDTA application to the heavy metals polluted soils and the stress on plant roots due to the abrupt increase metals concentration limit the wide commercial use of chelate-induced phytoextraction. Chelating agent ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) and auxin indole-3-acetic acid (IAA) were used for enhancing heavy metals uptake from soils by Zea mays L. (corn) in pot experiments. The metals content in plant tissues was quantified using an inductively coupled plasma mass spectrometer (ICP-MS). The results showed that the combination of IAA and EDTA increased the biomass by about 40.0% and the contents of Cu, Zn, Cd and Pb in corn shoots by 27.0%, 26.8%, 27.5% and 32.8% respectively, as compared to those in EDTA treatment. While NTA&IAA treatment increased the biomass by about 29.9% and the contents of Cu, Zn, Cd and Pb in corn shoots by 31.8%, 27.6%, 17.0% and 26.9% respectively, as compared to those in NTA treatment. These results indicated that corn growth was promoted, and the biomass and the accumulation of heavy metals in plant shoots were increased significantly with the addition of IAA, which probably helps to change the cell membrane properties and the biomass distribution, resulting in the alleviation of the phytotoxicity of metals and the chelating agents.

  3. Heavy metal contamination in arable soils and vegetables around a sulfuric acid factory, China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juan [Department of Environmental Science and Engineering, Guangzhou University, Guangzhou (China); Department of Earth Sciences, National Taiwan University, Taipei (China); Wang, Jin; Li, Xiangping; Chen, Yongheng; Wu, Yingjuan [Department of Environmental Science and Engineering, Guangzhou University, Guangzhou (China); Qi, Jianying [South China Institute of Environmental Science, Ministry of Environmental Protection (SCIES-MEP), Guangzhou (China); Wang, Chunlin [Research Center for Environmental Science, Guangdong Provincial Academy of Environmental Science, Guangzhou (China)

    2012-07-15

    This study was designed to investigate heavy metal (Tl, Pb, Cu, Zn, and Ni) contamination levels of arable soils and vegetables grown in the vicinity of a sulfuric acid factory in the Western Guangdong Province, China. Health risks associated with these metals by consumption of vegetables were assessed based on the hazard quotient (HQ). The soils show a most significant contamination of Tl, followed by Pb, Cu, Zn, and Ni. The heavy metal contents ({mu}g/g, dry weight basis) in the edible parts of vegetables range from 5.60 to 105 for Tl, below detection limit to 227 for Pb, 5.0-30.0 for Cu, 10.0-82.9 for Zn, and 0.50-26.0 for Ni, mostly exceeding the proposed maximum permissible level in Germany or China. For the studied vegetables, the subterranean part generally bears higher contents of Tl and Zn than the aerial part, while the former has lower contents of Cu and Ni than the latter. In addition, the results reveal that Tl is the major risk contributor for the local people since its HQ values are mostly much higher than 1.0. The potential health risk of Tl pollution in the food chain and the issue of food safety should be highly concerned and kept under continued surveillance and control. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Effects of petroleum and metal contaminated soil on plants and earthworms: Survival and bioaccumulation

    International Nuclear Information System (INIS)

    Tatem, H.E.; Simmers, J.W.; Skogerboe, J.G.; Lee, C.R.

    1993-01-01

    Earthworms, Eisenia foetida, and bermudagrass, Cynodon dactylon, were used in the laboratory to test the toxicity of contaminated sediment taken from a small fresh water lake in North Carolina. This work was part of an investigation to determine the potential effects of upland disposal of this sediment. The contaminated sediment contained As, Cr, Cu, Pb, Hg, Ni, Zn and petroleum hydrocarbons at concentrations much greater than nearby soils. Test cylinders were planted with bermudagrass; earthworms were added 30 days later. Both species were harvested at 60 days, weighed and submitted for chemical analyses. Cynodon was affected by the contaminated sediment but grew well in the mixtures of sediment and upland soil. Similar results were obtained with the Eisenia. These species did not accumulate hydrocarbons from the sediment with the possible exception of pyrene. The metals Cd, Pb, and Zn were elevated in plants exposed to the contaminated sediment. Earthworms exposed to this sediment accumulated Pb to concentrations greater than animals exposed to the manure control. This work demonstrated that a contaminated freshwater sediment was not toxic to plants or earthworms and that most petroleum hydrocarbons were not accumulated. The only metal that may be of some concern was Pb

  5. Phytoremediation of heavy metal contaminated soil potential by woody plants on Tonglushan ancient copper spoil heap in China.

    Science.gov (United States)

    Kang, Wei; Bao, Jianguo; Zheng, Jin; Xu, Fen; Wang, Liuming

    2018-01-02

    Fast-growing metal-accumulating woody plants are considered potential candidates for phytoremediation of metals. Tonglushan mining, one of the biggest Cu production bases in China, presents an important source of the pollution of environment. The sample was collected at Tonglushan ancient copper spoil heap. The aims were to measure the content of heavy metal in the soil and woody plants and to elucidate the phytoremediation potential of the plants. The result showed that soil Cu, Cd and Pb were the main contamination, the mean contents of which were 3166.73 mg/kg, 3.66 mg/kg and 137.06 mg/kg respectively, which belonged to severe contamination. Fourteen species from 14 genera of 13 families were collected and investigated; except for Ligutrum lucidum, the other 13 woody plants species were newly recorded in this area. In addition, to assess the ability of metal accumulation of these trees, we proposed accumulation index. Data suggested that Platanus × acerilolia, Broussonetia papyrifera, Ligutrum lucidum, Viburnum awabuki, Firmiana simplex, Robina pseudoacacia, Melia azedarach and Osmanthus fragrans exhibited high accumulated capacity and strong tolerance to heavy metals. Therefore, Platanus × acerilolia and Broussonetia papyrifera can be planted in Pb contaminated areas; Viburnum awabuki, Firmiana simplex, Robina pseudoacacia and Melia azedarach are the suitable trees for Cd contaminated areas; Viburnum awabuki, Melia azedarach, Ligutrum lucidum, Firmiana simplex, Osmanthus fragrans and Robina pseudoacacia are appropriate to Cu, Pb and Cd multi-metal contaminated areas.

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

    Directory of Open Access Journals (Sweden)

    Mathan Jayaraman

    2014-08-01

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

  7. Residual effects of metal contamination on the soil quality: a field survey in central Portugal

    Science.gov (United States)

    Kikuchi, Ryunosuke; Gerardo, Romeu

    2017-04-01

    Agriculture is an important source of income and employment. But depletion and degradation of land challenge to producing safe food and other agricultural products to sustain livelihoods and meet the needs of urban populations. When developing or expanding an agricultural area, it becomes essential to access the soil quality. Even if the present source of contamination is not observed, it is a worth subject to evaluate whether or not any negative effects of the post contamination still last. For this purpose, a field survey (2 ha) was carried: a zinc and lead mining site that was abandoned about 50 years ago was researched at Sanguinheiro (40°18'N and 8°21'W) in Central Portugal. The area is characterized by very steep slopes that are confining with a small stream. The obtained results show that (i) the Pb content in the site (165 mg/kg) is higher than that in the background (67.7 mg/kg); (ii) the Zn content of local vegetation (Eucalyptus globulus) in the post-mining site is 2.1 times that in the control site, and (iii) dead bare ground is observed in some parts of the site. There is a possibility that great amounts of Zn and Pb accumulate in tissues of local vegetation. Although mining activity ended 50 years ago, the contents of Pb and Zn in the sampled soil were comparatively high in the site with about a 75% slope. It is concluded that not only the present contamination but also the post-environmental stress should be assessed to properly develop an agricultural area in terms of securing agricultural products.

  8. 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.

  9. Grey relational analysis for evaluating the effects of different rates of wine lees-derived biochar application on a plant-soil system with multi-metal contamination.

    Science.gov (United States)

    Xu, Min; Zhu, Qihong; Wu, Jun; He, Yan; Yang, Gang; Zhang, Xiaohong; Li, Li; Yu, Xiaoyu; Peng, Hong; Wang, Lilin

    2018-03-01

    In this study, grey relational analysis (GRA) was used to investigate the effects of different application rates of wine lees-derived biochar on a plant-soil system with multi-metal contamination. A pot experiment was conducted to determine rice growth in multi-metal-contaminated soil amended with samples of wine lees-derived biochar, and 47 indicators (including soil properties, microbial activity, and plant physiology) were selected as evaluation indexes to assess the plant-soil system. The results indicated that higher wine lees-derived biochar application rates (2% W/W) were favorable for soil fertility, the bioconcentration factor (BF), and the mobility factor (MF, %) (with the exception of Cr, Zn, and Hg), but an application of 1% produced the highest plant growth, enzymatic activities, and bacterial diversity. The richness of the bacterial communities was reduced in the soil amended with the wine lees-derived biochar. According to the GRA assessment, the 1% application rate of wine lees-derived biochar was more suitable for restoring the holistic plant-soil system than were the application rates of 0, 0.5, and 2% (W/W). Furthermore, this study shows that GRA is a useful method for evaluating plant-soil systems.

  10. Heavy metal accumulation by poplar in calcareous soil with various degrees of multi-metal contamination: implications for phytoextraction and phytostabilization.

    Science.gov (United States)

    Hu, Yahu; Nan, Zhongren; Su, Jieqiong; Wang, Ning

    2013-10-01

    The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg(-1)), Cu (8.21 mg kg(-1)), Pb (41.62 mg kg(-1)), and Zn (696 mg kg(-1)) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg(-1), respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH4NO3-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.

  11. Phytoremediation: role of terrestrial plants and aquatic macrophytes in the remediation of radionuclides and heavy metal contaminated soil and water.

    Science.gov (United States)

    Sharma, Sunita; Singh, Bikram; Manchanda, V K

    2015-01-01

    Nuclear power reactors are operating in 31 countries around the world. Along with reactor operations, activities like mining, fuel fabrication, fuel reprocessing and military operations are the major contributors to the nuclear waste. The presence of a large number of fission products along with multiple oxidation state long-lived radionuclides such as neptunium ((237)Np), plutonium ((239)Pu), americium ((241/243)Am) and curium ((245)Cm) make the waste streams a potential radiological threat to the environment. Commonly high concentrations of cesium ((137)Cs) and strontium ((90)Sr) are found in a nuclear waste. These radionuclides are capable enough to produce potential health threat due to their long half-lives and effortless translocation into the human body. Besides the radionuclides, heavy metal contamination is also a serious issue. Heavy metals occur naturally in the earth crust and in low concentration, are also essential for the metabolism of living beings. Bioaccumulation of these heavy metals causes hazardous effects. These pollutants enter the human body directly via contaminated drinking water or through the food chain. This issue has drawn the attention of scientists throughout the world to device eco-friendly treatments to remediate the soil and water resources. Various physical and chemical treatments are being applied to clean the waste, but these techniques are quite expensive, complicated and comprise various side effects. One of the promising techniques, which has been pursued vigorously to overcome these demerits, is phytoremediation. The process is very effective, eco-friendly, easy and affordable. This technique utilizes the plants and its associated microbes to decontaminate the low and moderately contaminated sites efficiently. Many plant species are successfully used for remediation of contaminated soil and water systems. Remediation of these systems turns into a serious problem due to various anthropogenic activities that have

  12. Variation in whole DNA methylation in red maple (Acer rubrum) populations from a mining region: association with metal contamination and cation exchange capacity (CEC) in podzolic soils.

    Science.gov (United States)

    Kalubi, K N; Mehes-Smith, M; Spiers, G; Omri, A

    2017-04-01

    Although a number of publications have provided convincing evidence that abiotic stresses such as drought and high salinity are involved in DNA methylation reports on the effects of metal contamination, pH, and cation exchange on DNA modifications are limited. The main objective of the present study is to determine the relationship between metal contamination and Cation exchange capacity (CEC) on whole DNA modifications. Metal analysis confirms that nickel and copper are the main contaminants in sampled sites within the Greater Sudbury Region (Ontario, Canada) and liming has increased soil pH significantly even after 30 years following dolomitic limestone applications. The estimated CEC values varied significantly among sites, ranging between 1.8 and 10.5 cmol(+) kg -1 , with a strong relationship being observed between CEC and pH (r = 0.96**). Cation exchange capacity, significantly lower in highly metal contaminated sites compared to both reference and less contaminated sites, was higher in the higher organic matter limed compared to unlimed sites. There was a significant variation in the level of cytosine methylation among the metal-contaminated sites. Significant and strong negative correlations between [5mdC]/[dG] and bioavailable nickel (r = -0.71**) or copper (r = -0.72**) contents were observed. The analysis of genomic DNA for adenine methylation in this study showed a very low level of [6N-mdA]/dT] in Acer rubrum plants analyzed ranging from 0 to 0.08%. Significant and very strong positive correlation was observed between [6N-mdA]/dT] and soil bioavailable nickel (r = 0.78**) and copper (r = 0.88**) content. This suggests that the increased bioavailable metal levels associated with contamination by nickel and copper particulates are associated with cytosine and adenine methylation.

  13. Assessment of water-soluble thiourea-formaldehyde (WTF) resin for stabilization/solidification (S/S) of heavy metal contaminated soils.

    Science.gov (United States)

    Liu, She-Jiang; Jiang, Jia-Yu; Wang, Shen; Guo, Yu-Peng; Ding, Hui

    2018-03-15

    Stabilization/Solidification (S/S) can be regarded as necessary for remediation of heavy metal contaminated soil. There is, however, solid agent is not very convenient to use. Water-soluble thiourea-formaldehyde (WTF) is a novel chelating agent, which has more practical applications. The process of WTF resin for S/S process of heavy metal contaminated soils was studied. Laboratory-prepared slurries, made of field soils spiked with Cd 2+ and Cr 6+ were treated with WTF resin. The toxicity characteristic leaching procedure (TCLP) showed that with 2 wt% WTF, in the neutral condition of soil after treatment for 7 d, the leaching concentrations of Cd 2+ and Cr 6+ in contaminated soil were decreased by 80.3% and 92.6% respectively. Moreover, Tessier sequence extraction procedure showed WTF resin reduced the leaching concentration by transforming heavy metal from exchange form to organic form. The structure of WTF is obtained according to elemental analysis result and reaction mechanism. Through analysis of the infrared spectrogram of WTF and WTF heavy mental chelating precipitation, WTF can form stable chelate with heavy mental through coordination. The significant groups are hydroxyl, nitrogen and sulphur function groups in WTF mainly. Toxicology test revealed that the WTF resin is nontoxic to microorganism in the soils. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2011-05-01

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

  15. Effects of metal-contaminated soil on the performance of young trees growing in model ecosystems under field conditions

    International Nuclear Information System (INIS)

    Hermle, Sandra; Guenthardt-Goerg, Madeleine S.; Schulin, Rainer

    2006-01-01

    Young Populus tremula, Salix viminalis, Betula pendula and Picea abies trees were grown together in large open-top chambers. The treatments were: without or with (Cu/Zn/Cd/Pb = 640/3000/10/90 mg kg -1 ) metal contamination in the topsoil, irrigation pH 3.5 or 5.5, and acidic or calcareous subsoil. Growth, metal allocation to foliage and wood, as well as leaf gas exchange were measured. Biomass was reduced in P. tremula and B. pendula by the metal-contaminated topsoil relative to uncontaminated topsoil, whereas in P. tremula photosynthesis and transpiration were decreased. These effects were related to the elevated foliar Zn accumulation in P. tremula. S. viminalis showed a significant reduction in growth and an increased Zn and Cd accumulation on acidic vs. calcareous subsoil. Acidic irrigation produced only a few significant effects. P. abies showed the lowest metal uptake and no growth response to metal contamination. - Four tree species had different responses to metal treatments

  16. Effects of selected soil properties on phytoremediation applicability for heavy-metal-contaminated soils in the Apulia region, Southern Italy.

    Science.gov (United States)

    Farrag, K; Senesi, N; Rovira, P Soler; Brunetti, G

    2012-11-01

    Phytoremediation is a well-known promising alternative to conventional approaches used for the remediation of diffused and moderated contaminated soils. The evaluation of the accumulation, availability, and interactions of heavy metals in soil is a priority objective for the possible use of phytoremediation techniques such as phytoextraction and phytostabilization. The soils used in this work were collected from a number of sites inside a protected area in the Apulia region (Southern Italy), which were contaminated by various heavy metals originated from the disposal of wastes of different sources of origin. Soils examined contained Cd, Cr, Cu, Ni, Pb, and Zn in amounts exceeding the critical limits imposed by EU and Italian laws. However, the alkaline conditions, high organic matter content, and silty to silty loamy texture of soils examined would suggest a reduced availability of heavy metals to plants. Due to the high total content but the low available fraction of heavy metals analyzed, especially Cr, phytoextraction appears not to be a promising remediation approach in the sites examined, whereas phytostabilization appears to be the best technique for metal decontamination in the studied areas.

  17. Effects of long-term radionuclide and heavy metal contamination on the activity of microbial communities, inhabiting uranium mining impacted soils.

    Science.gov (United States)

    Boteva, Silvena; Radeva, Galina; Traykov, Ivan; Kenarova, Anelia

    2016-03-01

    Ore mining and processing have greatly altered ecosystems, often limiting their capacity to provide ecosystem services critical to our survival. The soil environments of two abandoned uranium mines were chosen to analyze the effects of long-term uranium and heavy metal contamination on soil microbial communities using dehydrogenase and phosphatase activities as indicators of metal stress. The levels of soil contamination were low, ranging from 'precaution' to 'moderate', calculated as Nemerow index. Multivariate analyses of enzyme activities revealed the following: (i) spatial pattern of microbial endpoints where the more contaminated soils had higher dehydrogenase and phosphatase activities, (ii) biological grouping of soils depended on both the level of soil contamination and management practice, (iii) significant correlations between both dehydrogenase and alkaline phosphatase activities and soil organic matter and metals (Cd, Co, Cr, and Zn, but not U), and (iv) multiple relationships between the alkaline than the acid phosphatase and the environmental factors. The results showed an evidence of microbial tolerance and adaptation to the soil contamination established during the long-term metal exposure and the key role of soil organic matter in maintaining high microbial enzyme activities and mitigating the metal toxicity. Additionally, the results suggested that the soil microbial communities are able to reduce the metal stress by intensive phosphatase synthesis, benefiting a passive environmental remediation and provision of vital ecosystem services.

  18. Quantitative analysis of the extent of heavy-metal contamination in soils near Picher, Oklahoma, within the Tar Creek Superfund Site.

    Science.gov (United States)

    Beattie, Rachelle E; Henke, Wyatt; Davis, Conor; Mottaleb, M Abdul; Campbell, James H; McAliley, L Rex

    2017-04-01

    The Tri-State Mining District of Missouri, Kansas and Oklahoma was the site of large-scale mining operations primarily for lead and zinc until the mid-1950s. Although mining across the area has ceased, high concentrations of heavy metals remain in the region's soil and water systems. The town of Picher, Ottawa County, OK, lies within this district and was included in the Tar Creek Superfund Site by the U.S. Environmental Protection Agency in 1980 due to extensive contamination. To elucidate the extent of heavy-metal contamination, a soil-chemistry survey of the town of Picher was conducted. Samples (n = 111) were collected from mine tailings, locally known as chat, in Picher and along cardinal-direction transects within an 8.05-km radius of the town in August 2015. Samples were analyzed for soil pH, moisture, and metal content. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analyses of 20 metals showed high concentrations of lead (>1000 ppm), cadmium (>40 ppm) and zinc (>4000 ppm) throughout the sampled region. Soil moisture content ranged from 0.30 to 35.9%, and pH values ranged from 5.14 to 7.42. MANOVA of metal profiles determined that soils collected from the north transect and chat were significantly different (p zinc were correlated with one another. These data show an unequal distribution of contamination surrounding the Picher mining site. Mapping heavy-metal contamination in these soils represents the first step in understanding the distribution of these contaminants at the Picher mining site. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Optimizing the molarity of a EDTA washing solution for saturated-soil remediation of trace metal contaminated soils

    International Nuclear Information System (INIS)

    Andrade, M.D.; Prasher, S.O.; Hendershot, W.H.

    2007-01-01

    Three experiments were conducted to optimize the use of ethylenediaminetetraacetic acid (EDTA) for reclaiming urban soils contaminated with trace metals. As compared to Na 2 EDTA (NH 4 ) 2 EDTA extracted 60% more Zn and equivalent amounts of Cd, Cu and Pb from a sandy loam. When successively saturating and draining loamy sand columns during a washing cycle, which submerged it once with a (NH 4 ) 2 EDTA wash and four times with deionised water, the post-wash rinses largely contributed to the total cumulative extraction of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. Both the washing solution and the deionised water rinses were added in a 2:5 liquid to soil (L:S) weight ratio. For equal amounts of EDTA, concentrating the washing solution and applying it and the ensuing rinses in a smaller 1:5 L:S weight ratio, instead of a 2:5 L:S weight ratio, increased the extraction of targeted Cr, Cu, Ni, Pb and Zn. - A single EDTA addition is best utilised in a highly concentrated washing solution given in a small liquid to soil weight ratio

  20. The hyperaccumulator Sedum plumbizincicola harbors metal-resistant endophytic bacteria that improve its phytoextraction capacity in multi-metal contaminated soil.

    Science.gov (United States)

    Ma, Ying; Oliveira, Rui S; Nai, Fengjiao; Rajkumar, Mani; Luo, Yongming; Rocha, Inês; Freitas, Helena

    2015-06-01

    Endophyte-assisted phytoremediation has recently been suggested as a successful approach for ecological restoration of metal contaminated soils, however little information is available on the influence of endophytic bacteria on the phytoextraction capacity of metal hyperaccumulating plants in multi-metal polluted soils. The aims of our study were to isolate and characterize metal-resistant and 1-aminocyclopropane-1-carboxylate (ACC) utilizing endophytic bacteria from tissues of the newly discovered Zn/Cd hyperaccumulator Sedum plumbizincicola and to examine if these endophytic bacterial strains could improve the efficiency of phytoextraction of multi-metal contaminated soils. Among a collection of 42 metal resistant bacterial strains isolated from the tissues of S. plumbizincicola grown on Pb/Zn mine tailings, five plant growth promoting endophytic bacterial strains (PGPE) were selected due to their ability to promote plant growth and to utilize ACC as the sole nitrogen source. The five isolates were identified as Bacillus pumilus E2S2, Bacillus sp. E1S2, Bacillus sp. E4S1, Achromobacter sp. E4L5 and Stenotrophomonas sp. E1L and subsequent testing revealed that they all exhibited traits associated with plant growth promotion, such as production of indole-3-acetic acid and siderophores and solubilization of phosphorus. These five strains showed high resistance to heavy metals (Cd, Zn and Pb) and various antibiotics. Further, inoculation of these ACC utilizing strains significantly increased the concentrations of water extractable Cd and Zn in soil. Moreover, a pot experiment was conducted to elucidate the effects of inoculating metal-resistant ACC utilizing strains on the growth of S. plumbizincicola and its uptake of Cd, Zn and Pb in multi-metal contaminated soils. Out of the five strains, B. pumilus E2S2 significantly increased root (146%) and shoot (17%) length, fresh (37%) and dry biomass (32%) of S. plumbizincicola as well as plant Cd uptake (43%), whereas

  1. Phytoextraction and phytostabilization potential of plants grown in the vicinity of heavy metal-contaminated soils: a case study at an industrial town site.

    Science.gov (United States)

    Lorestani, B; Yousefi, N; Cheraghi, M; Farmany, A

    2013-12-01

    With the development of urbanization and industrialization, soils have become increasingly polluted by heavy metals. Phytoremediation, an emerging cost-effective, nonintrusive, and aesthetically pleasing technology that uses the remarkable ability of plants to concentrate elements, can be potentially used to remediate metal-contaminated sites. In this research, two processes of phytoremediation (phytoextraction and phytostabilization) were surveyed in some plant species around an industrial town in the Hamedan Province in the central-western part of Iran. To this purpose, shoots and roots of the seven plant species and the associated soil samples were collected and analyzed by measuring Pb, Fe, Mn, Cu, and Zn concentrations using ICP-AES and then calculating the biological absorption coefficient, bioconcentration factor, and translocation factor parameters for each element. The obtained results showed that among the collected plants, Salsola soda is the most effective species for phytoextraction and phytostabilization and Cirsium arvense has the potential for phytostabilization of the measured heavy metals.

  2. Direct and indirect effects of metal contamination on soil biota in a Zn-Pb post-mining and smelting area (S Poland)

    International Nuclear Information System (INIS)

    Kapusta, Pawel; Szarek-Lukaszewska, Grazyna; Stefanowicz, Anna M.

    2011-01-01

    Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity. - Highlights: → Bioavailable zinc and cadmium reduce enchytraeid density. → Enchytraeids positively influence microbial respiration and biomass. → Total contents of heavy metals in soil are poor predictors of the distribution of plants and soil biota. - Elevated concentrations of exchangeable Zn and Cd reduce enchytraeid density and indirectly affect microbial activity adversely.

  3. Direct and indirect effects of metal contamination on soil biota in a Zn-Pb post-mining and smelting area (S Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Kapusta, Pawel, E-mail: p.kapusta@botany.pl [Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow (Poland); Szarek-Lukaszewska, Grazyna; Stefanowicz, Anna M. [Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Krakow (Poland)

    2011-06-15

    Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity. - Highlights: > Bioavailable zinc and cadmium reduce enchytraeid density. > Enchytraeids positively influence microbial respiration and biomass. > Total contents of heavy metals in soil are poor predictors of the distribution of plants and soil biota. - Elevated concentrations of exchangeable Zn and Cd reduce enchytraeid density and indirectly affect microbial activity adversely.

  4. 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.

  5. Application of bioassays with Enchytraeus crypticus and Folsomia candida to evaluate the toxicity of a metal-contaminated soil, before and after remediation

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Veronica; Simon, Mariano [Univ. de Almeria (Spain). Dept. de Edafologia y Quimica Agricola; Dietz-Ortiz, Maria; Gestel, Cornelis A.M. van [VU Univ., Amsterdam (Netherlands). Dept. of Animal Ecology

    2011-10-15

    A contaminated soil was amended to reduce bioavailability of metals (As, Cd, Cu, Pb, and Zn) and to modify its potential environmental impacts. Reproduction toxicity tests using two different soil invertebrates, Enchytraeus crypticus and Folsomia candida, were used to evaluate efficiency of soil amendments to reduce metal availability. This study has been carried out on a very contaminated soil from El Arteal mining district (SE Spain). The amendments used were marble sludge from the cutting and polishing of marble, compost from greenhouse wastes, and synthetic iron oxides. Soils were analyzed for cation exchange capacity, organic carbon and calcium carbonate content, particle size distribution, pH, electrical conductivity, and total metal content. Porewater and 0.01 M CaCl{sub 2}-extractable concentrations were measured in unamended and amended soils. Soil organisms were exposed to all treatments and to untreated soil. The parameters evaluated in both bioassays were survival and reproduction. All treatments decreased the porewater and CaCl{sub 2}-extractable concentrations of Zn, Pb, Cd, and Cu. The amendments increased survival and reproduction of E. crypticus, reducing toxicity. Survival of F. candida was also increased by the treatments; its reproduction did, however, not improve. These differences may be due to other factors that may affect collembolan reproduction. The different sensitivity of each test organism to some soil properties such as pH and electrical conductivity, which can affect reproduction, should be considered before interpreting results from bioassays focussed on toxicity due to pollutants. Reproduction toxicity bioassays with soil invertebrates are a good complement of chemical analysis to properly assess the ecological risk of remediation processes. Organisms with different exposure routes and different sensitivities to soil properties should be used simultaneously to assess the environmental risk of metal-contaminated sites and to evaluate

  6. 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.

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

    International Nuclear Information System (INIS)

    Kuo, S.; Lai, M.S.; Lin, C.W.

    2006-01-01

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

  8. 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.

  9. Simulation of changes in heavy metal contamination in farmland soils of a typical manufacturing center through logistic-based cellular automata modeling.

    Science.gov (United States)

    Qiu, Menglong; Wang, Qi; Li, Fangbai; Chen, Junjian; Yang, Guoyi; Liu, Liming

    2016-01-01

    A customized logistic-based cellular automata (CA) model was developed to simulate changes in heavy metal contamination (HMC) in farmland soils of Dongguan, a manufacturing center in Southern China, and to discover the relationship between HMC and related explanatory variables (continuous and categorical). The model was calibrated through the simulation and validation of HMC in 2012. Thereafter, the model was implemented for the scenario simulation of development alternatives for HMC in 2022. The HMC in 2002 and 2012 was determined through soil tests and cokriging. Continuous variables were divided into two groups by odds ratios. Positive variables (odds ratios >1) included the Nemerow synthetic pollution index in 2002, linear drainage density, distance from the city center, distance from the railway, slope, and secondary industrial output per unit of land. Negative variables (odds ratios <1) included elevation, distance from the road, distance from the key polluting enterprises, distance from the town center, soil pH, and distance from bodies of water. Categorical variables, including soil type, parent material type, organic content grade, and land use type, also significantly influenced HMC according to Wald statistics. The relative operating characteristic and kappa coefficients were 0.91 and 0.64, respectively, which proved the validity and accuracy of the model. The scenario simulation shows that the government should not only implement stricter environmental regulation but also strengthen the remediation of the current polluted area to effectively mitigate HMC.

  10. Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

    Science.gov (United States)

    Mucke, D.

    2012-04-01

    Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analysis of contaminated soils by XRF Dieter Mucke, Rolf Kumann, Sebastian Baldauf GEOMONTAN Gesellschaft für Geologie und Bergbau mbH&Co.KG, Muldentalstrasse 56, 09603 Rothenfurth, Saxony/Germany For hundreds of years in the Ore Mountains between Bohemia and Saxony silver and other ores are produced and smelted. Sulphide- and sulpharsenide-ores needed to be roasted first. In doing so the sulphide sulphur was oxidised under formation of sulphur dioxide SO2 and arsenide conversed into elemental arsenic and arsenide trioxide As2O3 respectively. Also the metals lead, cadmium and zinc are components of hut smokes, in the field of nickel foundries also nickel. The contents of soils basically reflect the geogenic conditions, which are caused by decomposition- and relocation-effects of the mineralisations, in the area of foundries also with influences by with the hut smokes anthropogenic mobilised elements. The Saxonian Agency for Environment and Geology drafted in 1992 a Soil Investigation Program with the aim of investigation of the contamination of Saxonian soils with arsenic and toxic heavy metals. In order of this Agency GEOMONTAN investigated 1164 measuring points in the grid 4 * 4 km.soil profiles and extracted soil samples for analysis. In the result of the laboratory examinations the Agency edited the "Soil atlas of the Free State of Saxony". 27 elements, pH and PAK are shown in detailed maps and allow in whole Saxony the first assessment of the contamination of soils with arsenic and toxic heavy metals. Each of the investigated soil profiles represent an area of 16 km2. Already by the different use of the districts (agricultural, industrial, urban) restricts representative values. GEOMONTAN in the meantime used at the exploration of a copper deposit in Brandenburg/Germany with approx. 50,000 single tests at drill cores a very fast low-cost method: the X Ray fluorescence

  11. Enumeration and characterization of arsenic-tolerant diazotrophic bacteria in a long-term heavy-metal-contaminated soil

    OpenAIRE

    Oliveira, A.; Pampulha, M.E.; Neto, M.M.; Almeida, A.C.

    2009-01-01

    The abundance of arsenic-tolerant diazotrophic bacteria was compared in a long-term contaminated soil versus a non-contaminated one. In addition, the characterization of tolerant diazotrophic bacteria was carried out. Differences in the number of heterotrophic N2 fixers were found between soils. Contaminated soil showed a decrease in the microbial population size of about 80%, confirming the great sensitivity of this group of soil bacteria to metals. However, quantitat...

  12. Transcriptome Response to Heavy Metals in Sinorhizobium meliloti CCNWSX0020 Reveals New Metal Resistance Determinants That Also Promote Bioremediation by Medicago lupulina in Metal-Contaminated Soil.

    Science.gov (United States)

    Lu, Mingmei; Jiao, Shuo; Gao, Enting; Song, Xiuyong; Li, Zhefei; Hao, Xiuli; Rensing, Christopher; Wei, Gehong

    2017-10-15

    metal-contaminated soils. Considering the plant-growth-promoting traits and survival advantage of metal-resistant rhizobia in contaminated environments, more heavy metal-resistant rhizobia and genetically manipulated strains were investigated. In view of the genetic diversity of metal resistance determinants in rhizobia, their effects on phytoremediation by the rhizobium-legume symbiosis must be different and depend on their specific assigned functions. Our work provides a better understanding of the mechanism of heavy metal resistance determinants involved in the rhizobium-legume symbiosis, and in further studies, genetically modified rhizobia harboring effective heavy metal resistance determinants may be engineered for the practical application of rhizobium-legume symbiosis for bioremediation in metal-contaminated soils. Copyright © 2017 American Society for Microbiology.

  13. Health risk assessment of heavy metals contamination in tomato and green pepper plants grown in soils amended with phosphogypsum waste materials.

    Science.gov (United States)

    Al-Hwaiti, Mohammad; Al-Khashman, Omar

    2015-04-01

    Phosphogypsum (PG) is a waste produced by the phosphate fertilizer industry that has relatively high concentrations of some heavy metals (e.g., Cd, Cr, Cu, Pb, V, and Zn). The present study was conducted to investigate heavy metal contamination in soils and vegetables (tomatoes and green peppers) and to evaluate the possible health risks associated with the consumption of vegetables grown in PG-amended soils. The enrichment factor values indicated that Pb, Cr, Cu, Ni, Zn, and V were depleted to minimally enriched, and Cd was moderately enriched. The pollution load index values indicated that the PG-amended soils were strongly polluted with Cd, moderately polluted with Cr and Ni, and slightly polluted with Pb, Cu, Zn and V. The geo-accumulation index values indicated that the PG-amended soils were uncontaminated with Pb, Cr, Cu, Ni, Zn, V, and moderately contaminated with Cd. The trace metal transfer for Cd, Cr, Pb, and Zn concentrations was below what are considered as acceptable limits ( Pb > Cd > Cr. The biological absorption coefficients in plants are, in order of highest to lowest, Pb > Zn > Cd > Cr, which suggests that Pb is more bioavailable to plants than Cd, Cr, and Zn. Furthermore, this study highlights that both adults and children consuming vegetables (e.g., tomatoes and green peppers) grown in PG-amended soils ingest significant amounts of the metals studied. However, the daily intake of metals (DIM) and the health risk index (HRI) values are contaminated soils, which were not included in this study.

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

    Science.gov (United States)

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

    2011-10-01

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

  15. Physicochemical Characteristics and Ecological Risk Assessment of Heavy Metals Contaminated Soils in Copper Mining of Nulasai, Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Dina·Tursenjan

    2017-12-01

    Full Text Available Taking the mining areas, tailings and surrounding farmland soil of the Nulasai copper mine in Xinjiang as the research object, the characteristics of soil physical and characteristics of heavy metal contents in this area were studied, and their ecological and environmental risks were preliminarily evaluated. The results showed that due to the long-term impact of mining wastewater, soil pH in the Nulasai mining area was relatively low. Soil conductivity and salt content were higher than those in the surrounding farmland, while soil organic matter, available nitrogen, available potassium and available phosphorus were lower than those in the surrounding farmland. The contents of heavy metals Cr, Cd, Pb, Cu, Ni and Zn in the mining area, tailing area and farmland soil were all lower than those in Xinjiang except for Cu. Overall, the heavy metal content of the soil manifested the area > tailing area > farmland. Single factor(Pi, Nemerow comprehensive pollution index(I and potential ecological risk index(RI indicated that the ecological risk of heavy metals in the soil around the mining area was manifested tailings > mining area > farmland. The potential ecological risk index of heavy metals in 0~30 cm topsoil was higher than that in 30~70 cm deep soil, but the overall ecological risk was lower in different land use types.

  16. Metal-resistant rhizobacteria isolates improve Mucuna deeringiana phytoextraction capacity in multi-metal contaminated soils from a gold mining area.

    Science.gov (United States)

    Boechat, Cácio Luiz; Giovanella, Patricia; Amorim, Magno Batista; de Sá, Enilson Luiz Saccol; de Oliveira Camargo, Flávio Anastácio

    2017-01-01

    Phytoremediation consists of biological techniques for heavy metal remediation, which include exploring the genetic package of vegetable species to remove heavy metals from the environment. The goals of this study were to investigate heavy metal and bioaugmentation effects on growth and nutrient uptake by Mucuna deeringiana; to determine the metal translocation factor and bioconcentration factor and provide insight for using native bacteria to enhance heavy metal accumulation. The experiment was conducted under greenhouse conditions using a 2 × 4 factorial scheme with highly and slightly contaminated soil samples and inoculating M. deeringiana with three highly lead (Pb +2 )-resistant bacteria Kluyvera intermedia (Ki), Klebsiella oxytoca (Ko), and Citrobacter murliniae (Cm) isolated from the rhizosphere of native plants identified as Senecio brasiliensis (Spreng.) Less., Senecio leptolobus DC., and Baccharis trimera (Less) DC., respectively. The increased heavy metal concentrations in soil samples do not decrease the root dry mass of M. deeringiana, concerning the number and dry weight of nodules. The shoot dry mass is reduced by the increasing concentration of heavy metals in soil associated with Kluyvera intermedia and Klebsiella oxytoca bacteria. The number of nodules is affected by heavy metals associated with Citrobacter murliniae bacteria. The bacteria K. intermedia, C. murliniae, and K. oxytoca increase the lead and cadmium available in the soil and enhanced metal uptake by Mucuna deeringiana. The M. deeringiana specie has characteristics that make it hyperaccumulate copper and zinc. The translocation and bioconcentration factors for M. deeringiana characterize it as a promising candidate to phytostabilize multi-metal contaminated soils.

  17. Role of extrinsic arbuscular mycorrhizal fungi in heavy metal-contaminated wetlands with various soil moisture levels.

    Science.gov (United States)

    Zheng, S; Wang, C; Shen, Z; Quan, Y; Liu, X

    2015-01-01

    This study presents an efficient heavy metal (HM) control method in HM-contaminated wetlands with varied soil moisture levels through the introduction of extrinsic arbuscular mycorrhizal fungi (AMF) into natural wetland soil containing indigenous AMF species. A pot culture experiment was designed to determine the effect of two soil water contents (5-8% and 25-30%), five extrinsic AMF inoculants (Glomus mosseae, G. clarum, G. claroideum, G. etunicatum, and G. intraradices), and HM contamination on root colonization, plant growth, and element uptake of common reed (Phragmites australis (Cav.) Trin. ex Steudel) plantlets in wetland soils. This study showed the prevalence of mycorrhizae in the roots of all P. australis plantlets, regardless of extrinsic AMF inoculations, varied soil moisture or HM levels. It seems that different extrinsic AMF inoculations effectively lowered HM concentrations in the aboveground tissues of P. australis at two soil moisture levels. However, metal species, metal concentrations, and soil moisture should also be very important factors influencing the elemental uptake performance of plants in wetland ecosystems. Besides, the soil moisture level significantly influenced plant growth (including height, and shoot and root dry weight (DW)), and extrinsic AMF inoculations differently affected shoot DW.

  18. Continuous treatment of heavy metal contaminated clay soils by extraction in stirred tanks and in a countercurrent column

    NARCIS (Netherlands)

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

    1991-01-01

    Extn. of metals from 2 contaminated waste site clay soils by 0.1-0.3 N HCl solns. was tested in 3 lab. scale, continuous processes: 2 stirred tank reactors (CSTR' s) in series; a countercurrent sieve-plate column fed with flocculated clay soil materials; and a combination of tank reactor and column.

  19. Soil Carbon Dioxide Production and Surface Fluxes: Subsurface Physical Controls

    Science.gov (United States)

    Risk, D.; Kellman, L.; Beltrami, H.

    Soil respiration is a critical determinant of landscape carbon balance. Variations in soil temperature and moisture patterns are important physical processes controlling soil respiration which need to be better understood. Relationships between soil respi- ration and physical controls are typically addressed using only surface flux data but other methods also exist which permit more rigorous interpretation of soil respira- tion processes. Here we use a combination of subsurface CO_{2} concentrations, surface CO_{2} fluxes and detailed physical monitoring of the subsurface envi- ronment to examine physical controls on soil CO_{2} production at four climate observatories in Eastern Canada. Results indicate that subsurface CO_{2} produc- tion is more strongly correlated to the subsurface thermal environment than the surface CO_{2} flux. Soil moisture was also found to have an important influence on sub- surface CO_{2} production, particularly in relation to the soil moisture - soil profile diffusivity relationship. Non-diffusive profile CO_{2} transport appears to be im- portant at these sites, resulting in a de-coupling of summertime surface fluxes from subsurface processes and violating assumptions that surface CO_{2} emissions are the result solely of diffusion. These results have implications for the study of soil respiration across a broad range of terrestrial environments.

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

    Science.gov (United States)

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

  1. Activity and functional diversity of microbial communities in long-term hydrocarbon and heavy metal contaminated soils

    Directory of Open Access Journals (Sweden)

    Markowicz Anna

    2016-12-01

    Full Text Available The impacts of long-term polycyclic aromatic hydrocarbons (PAHs and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni, moisture and conductivity than by PAHs.

  2. SOLID OXYGEN SOURCE FOR BIOREMEDIATION IN SUBSURFACE SOILS

    Science.gov (United States)

    Sodium percarbonate was encapsulated in poly(vinylidene chloride) to determine its potential as a slow-release oxygen source for biodegradation of contaminan ts in subsurface soils. In laboratory studies under aqueous conditions, the encapsulated sodium percarbonate was estimate...

  3. Phytoremediation potential of weeds in heavy metal contaminated soils of the Bassa Industrial Zone of Douala, Cameroon.

    Science.gov (United States)

    Lum, A Fontem; Ngwa, E S A; Chikoye, D; Suh, C E

    2014-01-01

    Phytoremediation is a promising option for reclaiming soils contaminated with toxic metals, using plants with high potentials for extraction, stabilization and hyperaccumulation. This study was conducted in Cameroon, at the Bassa Industrial Zone of Douala in 2011, to assess the total content of 19 heavy metals and 5 other elements in soils and phytoremediation potential of 12 weeds. Partial extraction was carried out in soil, plant root and shoot samples. Phytoremediation potential was evaluated in terms of the Biological Concentration Factor, Translocation Factor and Biological Accumulation Coefficient. The detectable content of the heavy metals in soils was Cu:70-179, Pb:8-130, Zn:200-971, Ni:74-296, Co:31-90, Mn:1983-4139, V:165-383, Cr:42-1054, Ba:26-239, Sc:21-56, Al:6.11-9.84, Th:7-22, Sr:30-190, La:52-115, Zr:111-341, Y:10-49, Nb:90-172 in mg kg(-1), and Ti:2.73-4.09 and Fe:12-16.24 in wt%. The contamination index revealed that the soils were slightly to heavily contaminated while the geoaccumulation index showed that the soils ranged from unpolluted to highly polluted. The concentration of heavy metals was ranked as Zn > Ni > Cu > V > Mn > Sc > Co > Pb and Cr in the roots and Mn > Zn > Ni > Cu > Sc > Co > V > Pb > Cr > Fe in the shoots. Dissotis rotundifolia and Kyllinga erecta had phytoextraction potentials for Pb and Paspalum orbicularefor Fe. Eleusine indica and K. erecta had phytostabilisation potential for soils contaminated with Cu and Pb, respectively.

  4. Heavy metal contamination of arable soil and corn plant in the vicinity of a zinc smelting factory and stabilization by liming.

    Science.gov (United States)

    Hong, Chang Oh; Gutierrez, Jessie; Yun, Sung Wook; Lee, Yong Bok; Yu, Chan; Kim, Pil Joo

    2009-02-01

    The heavy metal contamination in soils and cultivated corn plants affected by zinc smelting activities in the vicinity of a zinc smelting factory in Korea was studied. Soils and corn plants were sampled at the harvesting stage and analyzed for cadmium (Cd) and zinc (Zn) concentration, as well as Cd and Zn fraction and other chemical properties of soils. Cd and Zn were highly accumulated in the surface soils (0-20 cm), at levels higher than the Korean warning criteria (Cd, 1.5; Zn, 300 mg kg(-1)), with corresponding mean values of 1.7 and 407 mg kg(-1), respectively, but these metals decreased significantly with increasing soil depth and distance from the factory, implying that contaminants may come from the factory through aerosol dynamics (Hong et al., Kor J Environ Agr 26(3):204-209, 2007a; Environ Contam Toxicol 52:496-502, 2007b) and not from geological sources. The leaf part had higher Cd and Zn concentrations, with values of 9.5 and 1733 mg kg(-1), compared to the stem (1.6 and 547 mg kg(-1)) and grain (0.18 and 61 mg kg(-1)) parts, respectively. Cd and Zn were higher in the oxidizable fraction, at 38.5% and 46.9% of the total Cd (2.6 mg kg(-1)) and Zn (407 mg kg(-1)), but the exchangeable + acidic fraction of Cd and Zn as the bioavailable phases was low, 0.2 and 50 mg kg(-1), respectively. To study the reduction of plant Cd and Zn uptake by liming, radish (Raphanus sativa L.) was cultivated in one representative field among the sites investigated, and Ca(OH)(2) was applied at rates of 0, 2, 4, and 8 mg ha(-1). Plant Cd and Zn concentrations and NH(4)OAc extractable Cd and Zn concentrations of soil decreased significantly with increasing Ca(OH)(2) rate, since it markedly increases the cation exchange capacity of soil induced by increased pH. As a result, liming in this kind of soil could be an effective countermeasure in reducing the phytoextractability of Cd and Zn.

  5. Combination of bioleaching by gross bacterial biosurfactants and flocculation: A potential remediation for the heavy metal contaminated soils.

    Science.gov (United States)

    Yang, Zhihui; Shi, Wei; Yang, Weichun; Liang, Lifen; Yao, Wenbin; Chai, Liyuan; Gao, Shikang; Liao, Qi

    2018-09-01

    Combining bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 and flocculation by poly aluminium chloride (PAC) was proposed to develop a potential environment-friendly and cost-effective technique to remediate the severely contaminated soils by heavy metals. The factors affecting soil bioleaching by the gross biosurfactants of Burkholderia sp. Z-90 were optimized. The results showed the optimal removing efficiencies of Zn, Pb, Mn, Cd, Cu, and As by the Burkholderia sp. Z-90 leachate were 44.0, 32.5, 52.2, 37.7, 24.1 and 31.6%, respectively at soil liquid ratio of 1:20 (w/v) for 5 d, which were more efficient than that by 0.1% of rhamnolipid. The amounts of the bioleached heavy metals by the Burkholderia sp. Z-90 leachate were higher than that by other biosurfactants in the previous studies, although the removal efficiencies of the metals by the leachate were relatively lower. It was suggested that more heavy metals caused more competitive to chelate with function groups of the gross biosurfactants and the metal removal efficiencies by biosurfactants in natural soils were lower than in the artificially contaminated soils. Moreover, the Burkholderia sp. Z-90 leachate facilitated the metals to be transformed to the easily migrating speciation fractions. Additional, the results showed that PAC was efficient in the following flocculation to remove heavy metals in the waste bio-leachates. Our study will provide support for developing a bioleaching technique model to remediate the soils extremely contaminated by heavy metals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Efficiency modeling of solidification/stabilization of multi-metal contaminated industrial soil using cement and additives.

    Science.gov (United States)

    Voglar, Grega E; Leštan, Domen

    2011-08-30

    In a laboratory study, formulations of 15% (w/w) of ordinary Portland cement (OPC), calcium aluminate cement (CAC) and pozzolanic cement (PC) and additives: plasticizers cementol delta ekstra (PCDE) and cementol antikorodin (PCA), polypropylene fibers (PPF), polyoxyethylene-sorbitan monooleate (Tween 80) and aqueous acrylic polymer dispersion (Akrimal) were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with up to 157, 32,175, 44,074, 7614, 253 and 7085mg kg(-1) of Cd, Pb, Zn, Cu, Ni and As, respectively. Soils formed solid monoliths with all cementitious formulations tested, with a maximum mechanical strength of 12N mm(-2) achieved after S/S with CAC+PCA. To assess the S/S efficiency of the used formulations for multi-element contaminated soils, we propose an empirical model in which data on equilibrium leaching of toxic elements into deionized water and TCLP (toxicity characteristic leaching procedure) solution and the mass transfer of elements from soil monoliths were weighed against the relative potential hazard of the particular toxic element. Based on the model calculation, the most efficient S/S formulation was CAC+Akrimal, which reduced soil leachability of Cd, Pb, Zn, Cu, Ni and As into deionized water below the limit of quantification and into TCLP solution by up to 55, 185, 8750, 214, 4.7 and 1.2-times, respectively; and the mass transfer of elements from soil monoliths by up to 740, 746, 104,000, 4.7, 343 and 181-times, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Heavy metal contamination and accumulation in soil and wild plant species from industrial area of Islamabad, Pakistan

    International Nuclear Information System (INIS)

    Malik, R.N.; Husain, S.Z.; Nazir, I.

    2010-01-01

    This study was designed to assess total contents of 6 toxic metals viz., Pb, Cu, Zn, Co, Ni, and Cr in the soil and plant samples of 16 plant species collected from industrial zone of Islamabad, Pakistan. The concentration, transfer and accumulation of metals from soil to roots and shoots was evaluated in terms of Biological Concentration Factor (BCF), Translocation Factor (TF) and Bioaccumulation Coefficient (BAC). Total metal concentrations of Pb, Zn, Cu, Co, Ni, and Cr in soils varied between 2.0-29.0, 61.9-172.6, 8.9 to 357.4, 7.3-24.7, 41.4-59.3, and 40.2-927.2 mg/kg. Total metal concentrations pattern in roots were: Cu>Cr>Zn>Ni>Pb>Co. Grasses showed relatively higher total Zn concentration. Accumulation of Cu was highest in shoots followed by Zn, Cr, Pb, Co and Ni. None of plant species were identified as hyper accumulator; however, based on BCFs, TFs, and BACs values, most of the studied species have potential for phyto stabilization and phyto extraction. Parthenium hysterophoirus L., and Amaranthus viridis L., is suggested for phytoextraction of Pb and Ni, whereas, Partulaca oleracea L., Brachiaria reptans (L.) Gard. and Hubb., Solanum nigrum L., and Xanthium stromarium L., for hytostabilization of soils contaminated with Pb and Cu. (author)

  8. Assessment of toxicity of heavy metal contaminated soils toward Collembola in paddy fields supported by laboratory tests

    DEFF Research Database (Denmark)

    Liu, Manping; Xu, Jie; Krogh, Paul Henning

    2018-01-01

    Effects on soil Collembola of Cu, Zn, Pb, and Cd pollution from Cu smelters over 40 years were investigated in paddy fields from an area of Eastern China. We compared the field effects to those observed in single-species laboratory tests employing the hemiedaphic collembolan Folsomia candida and ...

  9. Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China).

    Science.gov (United States)

    Liu, Hongyu; Probst, Anne; Liao, Bohan

    2005-03-01

    In 1985, the collapse of the tailing dam in Chenzhou lead/zinc mine (Hunan, southern China) led to the spread of mining waste spills on the farmland along the Dong River. After the accident, an urgent soil cleaning up was carried out in some places. Seventeen years later, cereal (rice, maize, and sorghum), pulses (soybean, Adzuki bean, mung bean and peanut), vegetables (ipomoea, capsicum, taro and string bean) and the rooted soils were sampled at four sites: (1) the mining area (SZY), (2) the area still covered with the mining tailing spills (GYB), (3) the cleaned area from mining tailing spills (JTC), and (4) a background site (REF). Metal concentrations in the crops and soils were analyzed to evaluate the long-term effects of the spilled waste on the soil and the potential human exposure through food chains. The results showed that the physical-chemical properties of the soils obviously changed due to the different farming styles used by each individual farmer. Leaching effects and plant extraction of metals from some soils were quite weak. Certain soils were still heavily polluted with As, Cd, Zn, Pb and Cu. The contamination levels were in the order of GYB>SZY>JTC showing that the clean-up treatment was effective. The maximum allowable concentration (MAC) levels for Chinese agricultural soils were still highly exceeded, particularly for As and Cd (followed by Zn, Pb and Cu), with mean concentrations of 709 and 7.6 mg kg(-1), respectively. These concentrations exceed the MAC levels by 24 times for As and 13 times for Cd at GYB. Generally, the edible leaves or stems of crops were more heavily contaminated than seeds or fruits. Ipomoea was the most severely contaminated crop. The concentrations of Cd and Pb were 3.30 and 76.9 mg kg(-1) in ipomoea leaves at GYB, which exceeded the maximum permit levels (0.5 mg kg(-1) for Cd and 9 mg kg(-1) for Pb) by 6.6 and 8.5 times, respectively. Taro (+skin) could accumulate high concentrations of Zn and Cd in the edible stem

  10. Possibility for using of two Paulownia lines as a tool for remediation of heavy metal contaminated soil.

    Science.gov (United States)

    Tzvetkova, Nikolina; Miladinova, Kamelya; Ivanova, Katya; Georgieva, Teodora; Geneva, Marya; Markovska, Yuliana

    2015-01-01

    One-year-old two Paulownia lines (Ptomentosa x fortunei--TF 01 and R elongata x fortunei--EF 02) were grown, as pot experiment, in soil collected from the field of waste depository of Kremikovtzi ferrous metallurgical industry near Sofia. The soil was heavily polluted with Cd. Metals content (Ca, Mg, K, Na, Cd, Cu, Pb, Zn and Fe) in soil and its distribution in roots, stems and leaves of both lines was studied. The results showed that Ca and K accumulated more in stem, Mg, Na, Fe and Cd in root, while Pb, Cu and Zn in the leaves of both lines. The bloaccumulation factor (BF) and translocation factor (TF) were evaluated in order to determine the potential of plants in removing metals from contaminated soil. The BF for Fe, Pb, Cu and Zn in TF 01 line exceeded that of EF 02 line--5.6; 1.03; 1.20; 1.14 times, respectively. TF was higher in TF 01 line for Fe, Pb and Cd (6.0; 1.92 and 1.03, respectively), but not for Cu and Zn. The success of phytoremediation depends on plant growth and restricted distribution of heavy metals in shoots. Our results showed that stem length and total leaf area of Paulownia elongata x fortunei were higher than Paulownia tomentosa x fortuneibut BF for Cu and Zn and TF for Pb was less. BF for Cd was 1.7 times higher and TF for Zn was 1.03 times higher in Paulownia elongata x fortunei. Selected two lines (P. tomentosa x fortunei--TF 01 and P elongataxfortunei--EF02) were accumulators of Cu, Zn and Cd. Paulownia tomentosax fortunei accumulated more Pb and Zn in aboveground parts, while Paulownia elongata x fortunei--accumulated Zn only. These lines proved to be a promising species for phytoremediation of heavy metal polluted soils due to high biomass productivity.

  11. Assisted phytoremediation of heavy metal contaminated soil from a mined site with Typha latifolia and Chrysopogon zizanioides.

    Science.gov (United States)

    Anning, Alexander Kofi; Akoto, Ruth

    2018-02-01

    Chemically assisted phytoremediation is fast gaining attention as a biotechnology to accelerate heavy metal removal from contaminated substrates, but how different chemical amendments affect the process remains an important research question. Here, bioaccumulation factor (BAF), translocation factor (TF), removal efficiency (RE) and uptake of Hg, As, Pb, Cu and Zn by cattail (Typha latifolia) and vetiver (Chrysopogon zizanioides) were quantified in a potted experiment to determine the effects of amendments on the phytoremediation success. Baseline concentrations of heavy metals within the studied mined site were determined. The experiment involved three soil treatments (each comprising 16 samples amended with 0.05mol/L ethylene di-aminetetraacetic acid (EDTA), 3g of aluminum sulfate [Al 2 (SO 4 ) 3 ], and unamended control) transplanted with equal numbers of vetiver and cattail. Growth performance (height) of plant species was monitored every two weeks. Sixteen weeks after transplanting, heavy metal levels in plant and soil samples were quantified following standard protocols, and the biomass and root length measured for each plant species. Results indicated strong negative impact of mining activities on heavy metal levels of soil in the study area. Soil amendment considerably enhanced the BAF, TF, RE and uptake but the effect varied with plant species and heavy metal in question. The amendment also stimulated strong positive correlation between RE and BAF, TF and metal uptake, and generally did not show any negative effects on plant growth performance. In general, soil amendment aided the accumulation and translocation of heavy metals in the plant species studied, and could be explored for cleaning up contaminated sites. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: implications for human exposure.

    Science.gov (United States)

    Ferri, Roberta; Hashim, Dana; Smith, Donald R; Guazzetti, Stefano; Donna, Filippo; Ferretti, Enrica; Curatolo, Michele; Moneta, Caterina; Beone, Gian Maria; Lucchini, Roberto G

    2015-06-15

    For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. Home gardens (n=63) were selected in three regions of varying ferroalloy plant activity durations in Brescia province. Total soil metal concentration and extractability were measured by X-Ray Fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1+F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references. We recommend thorough washing of vegetables

  13. Combined and Relative Effect Levels of Perceived Risk, Knowledge, Optimism, Pessimism, and Social Trust on Anxiety among Inhabitants Concerning Living on Heavy Metal Contaminated Soil.

    Science.gov (United States)

    Tang, Zhongjun; Guo, Zengli; Zhou, Li; Xue, Shengguo; Zhu, Qinfeng; Zhu, Huike

    2016-11-02

    This research aims at combined and relative effect levels on anxiety of: (1) perceived risk, knowledge, optimism, pessimism, and social trust; and (2) four sub-variables of social trust among inhabitants concerning living on heavy metal contaminated soil. On the basis of survey data from 499 Chinese respondents, results suggest that perceived risk, pessimism, optimism, and social trust have individual, significant, and direct effects on anxiety, while knowledge does not. Knowledge has significant, combined, and interactive effects on anxiety together with social trust and pessimism, respectively, but does not with perceived risk and optimism. Social trust, perceived risk, pessimism, knowledge, and optimism have significantly combined effects on anxiety; the five variables as a whole have stronger predictive values than each one individually. Anxiety is influenced firstly by social trust and secondly by perceived risk, pessimism, knowledge, and optimism. Each of four sub-variables of social trust has an individual, significant, and negative effect on anxiety. When introducing four sub-variables into one model, trust in social organizations and in the government have significantly combined effects on anxiety, while trust in experts and in friends and relatives do not; anxiety is influenced firstly by trust in social organization, and secondly by trust in the government.

  14. Heavy Metal Contamination and Ecological Risk Assessment of Swine Manure Irrigated Vegetable Soils in Jiangxi Province, China.

    Science.gov (United States)

    Wang, Maolan; Liu, Ronghao; Lu, Xiuying; Zhu, Ziyi; Wang, Hailin; Jiang, Lei; Liu, Jingjing; Wu, Zhihua

    2018-05-01

    Heavy metal are often added to animal fodder and accumulate in the soils with swine manure. In this study, heavy metal (Cu, Pb, Cd, Zn, As and Cr) concentrations were determined in agricultural soils irrigated with swine manure in Jiangxi Province, China. Results showed that the average concentrations of Cu, Zn, As and Cr (32.8, 93.7, 21.3 and 75.8 mg/kg, respectively) were higher than the background values, while Pb and Cd (15.2 and 0.090 mg/kg, respectively) were lower than the background values. Contamination factors [Formula: see text] indicated that they were generally moderate for Cu, Zn, As and Cr and generally low for Pb and Cd. The contamination degree (C d ) was calculated to be 7.5-10.0 indicating a moderate degree of contamination. The geoaccumulation index (I geo ) indicated that the soils were unpolluted with Zn, Cd and Pb, while unpolluted to moderately pollute with Cr, Cu and As. The single ecological risk factor [Formula: see text] revealed that the six heavy metals all belonged to low ecological risk. The ecological risk indices suggested that all the sampling sites were at low risk level.

  15. Comparison of three types of oil crop rotation systems for effective use and remediation of heavy metal contaminated agricultural soil.

    Science.gov (United States)

    Yang, Yang; Zhou, Xihong; Tie, Boqing; Peng, Liang; Li, Hongliang; Wang, Kelin; Zeng, Qingru

    2017-12-01

    Selecting suitable plants tolerant to heavy metals and producing products of economic value may be a key factor in promoting the practical application of phytoremediation polluted soils. The aim of this study is to further understand the utilization and remediation of seriously contaminated agricultural soil. In a one-year field experiment, we grew oilseed rape over the winter and then subsequently sunflowers, peanuts and sesame after the first harvest. This three rotation system produced high yields of dry biomass; the oilseed rape-sunflower, oilseed rape-peanut and oilseed rape-sesame rotation allowed us to extract 458.6, 285.7, and 134.5 g ha -1 of cadmium, and 1264.7, 1006.1, and 831.1 g ha -1 of lead from soil, respectively. The oilseed rape-sunflower rotation showed the highest phytoextraction efficiency (1.98%) for cadmium. Lead and cadmium in oils are consistent with standards after extraction with n-hexane. Following successive extractions with potassium tartrate, concentrations of lead and cadmium in oilseed rape and peanut seed meals were lower than levels currently permissible for feeds. Thus, this rotation system could be useful for local farmers as it would enable the generation of income during otherwise sparse phytoremediation periods. Copyright © 2017. Published by Elsevier Ltd.

  16. Field evaluation of in situ remediation of a heavy metal contaminated soil using lime and red-mud

    International Nuclear Information System (INIS)

    Gray, C.W.; Dunham, S.J.; Dennis, P.G.; Zhao, F.J.; McGrath, S.P.

    2006-01-01

    We evaluated the effectiveness of lime and red mud (by-product of aluminium manufacturing) to reduce metal availability to Festuca rubra and to allow re-vegetation on a highly contaminated brown-field site. Application of both lime and red mud (at 3 or 5%) increased soil pH and decreased metal availability. Festuca rubra failed to establish in the control plots, but grew to a near complete vegetative cover on the amended plots. The most effective treatment in decreasing grass metal concentrations in the first year was 5% red mud, but by year two all amendments were equally effective. In an additional pot experiment, P application in combination with red mud or lime decreased the Pb concentration, but not total uptake of Pb in Festuca rubra compared to red mud alone. The results show that both red mud and lime can be used to remediate a heavily contaminated acid soil to allow re-vegetation. - Red mud was effective in immobilising heavy metals in soil

  17. Field evaluation of in situ remediation of a heavy metal contaminated soil using lime and red-mud

    Energy Technology Data Exchange (ETDEWEB)

    Gray, C.W. [Agriculture and the Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Dunham, S.J. [Agriculture and the Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Dennis, P.G. [Agriculture and the Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Zhao, F.J. [Agriculture and the Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); McGrath, S.P. [Agriculture and the Environment Division, Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom)]. E-mail: steve.mcgrath@bbsrc.ac.uk

    2006-08-15

    We evaluated the effectiveness of lime and red mud (by-product of aluminium manufacturing) to reduce metal availability to Festuca rubra and to allow re-vegetation on a highly contaminated brown-field site. Application of both lime and red mud (at 3 or 5%) increased soil pH and decreased metal availability. Festuca rubra failed to establish in the control plots, but grew to a near complete vegetative cover on the amended plots. The most effective treatment in decreasing grass metal concentrations in the first year was 5% red mud, but by year two all amendments were equally effective. In an additional pot experiment, P application in combination with red mud or lime decreased the Pb concentration, but not total uptake of Pb in Festuca rubra compared to red mud alone. The results show that both red mud and lime can be used to remediate a heavily contaminated acid soil to allow re-vegetation. - Red mud was effective in immobilising heavy metals in soil.

  18. Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: Implications for human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ferri, Roberta [Occupational Health, University of Brescia (Italy); Hashim, Dana [Occupational and Environmental Medicine, Icahn School of Medicine at Mount Sinai, New York (United States); Smith, Donald R. [Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA (United States); Guazzetti, Stefano [Public Health Service, Reggio Emilia (Italy); Donna, Filippo [Occupational Health, University of Brescia (Italy); Ferretti, Enrica; Curatolo, Michele; Moneta, Caterina [Department of Food Chemistry, Metal Laboratory, IZSLER, Brescia (Italy); Beone, Gian Maria [Institute of Agricultural and Environmental Chemistry, Università Cattolica, Piacenza (Italy); Lucchini, Roberto G. [Occupational Health, University of Brescia (Italy); Occupational and Environmental Medicine, Icahn School of Medicine at Mount Sinai, New York (United States); Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA (United States)

    2015-06-15

    Background: For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. Methods: Home gardens (n = 63) were selected in three regions of varying ferroalloy plant activity durations in Brescia province. Total soil metal concentration and extractability were measured by X-Ray Fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. Results: Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. Conclusions: Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1 + F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references

  19. Metal contamination of home garden soils and cultivated vegetables in the province of Brescia, Italy: Implications for human exposure

    International Nuclear Information System (INIS)

    Ferri, Roberta; Hashim, Dana; Smith, Donald R.; Guazzetti, Stefano; Donna, Filippo; Ferretti, Enrica; Curatolo, Michele; Moneta, Caterina; Beone, Gian Maria; Lucchini, Roberto G.

    2015-01-01

    Background: For the past century, ferroalloy industries in Brescia province, Italy produced particulate emissions enriched in manganese (Mn), lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), iron (Fe), and aluminum (Al). This study assessed metal concentrations in soil and vegetables of regions with varying ferroalloy industrial activity levels. Methods: Home gardens (n = 63) were selected in three regions of varying ferroalloy plant activity durations in Brescia province. Total soil metal concentration and extractability were measured by X-Ray Fluorescence (XRF), aqua regia extraction, and modified Community Bureau of Reference (BCR) sequential extraction. Unwashed and washed spinach and turnips cultivated in the same gardens were analyzed for metal concentrations by flame atomic absorption spectrometry. Results: Median soil Al, Cd, Fe, Mn, Pb, and Zn concentrations were significantly higher in home gardens near ferroalloy plants compared to reference home gardens. The BCR method yielded the most mobile soil fraction (the sum of extractable metals in Fractions 1 and 2) and all metal concentrations were higher in ferroalloy plant areas. Unwashed spinach showed higher metal concentrations compared to washed spinach. However, some metals in washed spinach were higher in the reference area likely due to history of agricultural product use. Over 60% of spinach samples exceeded the 2- to 4-fold Commission of European Communities and Codex Alimentarius Commission maximum Pb concentrations, and 10% of the same spinach samples exceeded 2- to 3-fold maximum Cd concentrations set by both organizations. Turnip metal concentrations were below maximum standard reference values. Conclusions: Prolonged industrial emissions increase median metal concentrations and most soluble fractions (BCR F1 + F2) in home garden soils near ferroalloy plants. Areas near ferroalloy plant sites had spinach Cd and Pb metal concentrations several-fold above maximum standard references

  20. Comparison of EDTA- and citric acid-enhanced phytoextraction of heavy metals in artificially metal contaminated soil by Typha angustifolia.

    Science.gov (United States)

    Muhammad, Dawood; Chen, Fei; Zhao, Jing; Zhang, Guoping; Wu, Feibo

    2009-08-01

    A pot experiment was conducted to study the performance of EDTA and citric acid (CA) addition in improving phytoextraction of Cd, Cu, Pb, and Cr from artificially contaminated soil by T. angustifolia. T. angustifolia showed the remarkable resistance to heavy metal toxicity with no visual toxic symptom including chlorosis and necrosis when exposed to metal stress. EDTA-addition significantly reduced plant height and biomass, compared with the control, and stunted plant growth, while 2.5 and 5 mM CA addition induced significant increases in root dry weight. EDTA, and 5 and 10 mM CA significantly increased shoot Cd, Pb, and Cr concentrations compared with the control, with EDTA being more effective. At final harvest, the highest shoot Cd, Cr, and Pb concentrations were recorded in the treatment of 5 mM EDTA addition, while maximal root Pb concentration was found at the 2.5 mM CA treatment. However, shoot Cd accumulation in the 10 mM CA treatment was 36.9% higher than that in 2.5 mM EDTA, and similar with that in 10 mM EDTA. Shoot Pb accumulation was lower in 10 mM CA than that in EDTA treatments. Further, root Cd, Cu, and Pb accumulation of CA treatments and shoot Cr accumulation in 5 or 10 mM CA treatments were markedly higher than that of control and EDTA treatments. The results also showed that EDTA dramatically increased the dissolution of Cu, Cr, Pb, and Cd in soil, while CA addition had less effect on water-soluble Cu, Cr, and Cd, and no effect on Pb levels. It is suggested that CA can be a good chelator candidate for T. angustifolia used for environmentally safe phytoextraction of Cd and Cr in soils.

  1. Plant growth promotion and root colonization by EPS producing Enterobacter sp. RZS5 under heavy metal contaminated soil.

    Science.gov (United States)

    Sayyed, R Z; Patel, P R; Shaikh, S S

    2015-02-01

    The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 μM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 μM of Ca2+; 50 μM of Fe2+ and 60 μM of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) seed and peanut (Arachis hypogaea) seed. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

  2. Assessment of Heavy Metal Contamination in the Surrounding Soils and Surface Sediments in Xiawangang River, Qingshuitang District

    Science.gov (United States)

    Jiang, Min; Zeng, Guangming; Zhang, Chang; Ma, Xiaoying; Chen, Ming; Zhang, Jiachao; Lu, Lunhui; Yu, Qian; Hu, Langping; Liu, Lifeng

    2013-01-01

    Xiawanggang River region is considered to be one of the most polluted areas in China due to its huge amount discharge of pollutants and accumulation for years. As it is one branch of Xiang River and the area downstream is Changsha city, the capital of Hunan Province, the ecological niche of Xiawangang River is very important. The pollution treatment in this area was emphasized in the Twelfth Five-Year Plan of Chinese government for Xiang River Water Environmental Pollution Control. In order to assess the heavy metal pollution and provide the base information in this region for The Twelfth Five-Year Plan, contents and fractions of four heavy metals (Cd, Cu, Pb and Zn) covering both sediments and soils were analyzed to study their contamination state. Three different indexes were applied to assess the pollution extent. The results showed this area was severely polluted by the four heavy metals, and the total concentrations exceeded the Chinese environmental quality standard for soil, grade III, especially for Cd. Moreover, Cd, rated as being in high risk, had a high mobility as its great contents of exchangeable and carbonates fractions in spite of its relative low content. Regression analysis revealed clay could well explain the regression equation for Cd, Cu and Zn while pH and sand could significantly interpret the regression equation for Pb. Moreover, there was a significant correlation between Non-residual fraction and Igeo for all the four metals. Correlation analysis showed four metals maybe had similar pollution sources. PMID:23951103

  3. Risk Assessment of Heavy Metals Contamination in Soils and Selected Crops in Zanjan Urban and Industrial Regions

    Directory of Open Access Journals (Sweden)

    A. Afshari

    2016-02-01

    Full Text Available Introduction: Heavy metals are types of elements naturally present in soil or enter into soil as a result of human activities. The most important route of exposure to heavy metals is daily intake of food. Crops grown in contaminated soil (due to mining activities, industrial operations and agriculture may contain high concentrations of heavy metals. Also closeness to cities and industrial centers can have a great influence on the accumulation of heavy metals to agricultural products grown in the region. The study aimed to determine the concentration of heavy metals in soil and agricultural products around urban and industrial areas of Zanjan province (North West of Iran and consumption hazard probability. Materials and Methods: Soil (75 samples of soil from a depth of 0 to 10 cm and plant (101 samples samples, in the summer 2011, were randomly taken from industrial areas as follow: tomatoes (Lycopersicum esculentum M, wheat seed (Triticum vulgare, barley seeds (Hordeum vulgare, alfalfa shoots (Medicago sativa L., potato tubers (Solanumtuberosum L., apple fruit, vegetables and fruits such as Dill (Aniethum graveolens L., leek (Allium porrum L., Gardencress (Barbara verna L. and basil (Ocimum basilicum L.. Plant samples were then washed with distilled water, oven dried for48 hours at a temperature of 70 ´C until constant weight was attained and then they digested using 2 M hydrochloric acid (HCl and nitric acid digestion in 5 M. Concentrations of heavy metals in the soil and crops were determined by atomic absorption spectrometry. DTPA extraction of metals by Lindsay and Norvell (1978 method and sequential extraction method by Tessier et al. (1979 were performed. Statistical analysis was accomplished using the software SPSS 16.0 and the comparison of mean values was done using the Duncan test at the 5% level of significance. Results and Discussion: The magnitude of variations for total copper was from 11.5 to 352.5 (average 52.4, zinc was from 96

  4. Non-destructive soil amendment application techniques on heavy metal-contaminated grassland: Success and long-term immobilising efficiency.

    Science.gov (United States)

    Friesl-Hanl, Wolfgang; Platzer, Klaus; Riesing, Johann; Horak, Othmar; Waldner, Georg; Watzinger, Andrea; Gerzabek, Martin H

    2017-01-15

    Extensive contamination of grassland with cadmium (Cd), lead (Pb) and zinc (Zn) is a typical problem close to Pb/Zn smelter sites. The entry of Cd or Pb into the food chain is very likely, as are toxicity effects of Zn in plants. Previous promising results from pot and field experiments showed the high potential of using amendments for immobilisation to reduce metal input into the food chain via crops grown on smelter-contaminated soils at Arnoldstein (Austria) (Friesl et al., 2006). The aim of this study was to find a practical solution for large-scale contaminations in hilly regions that avoids erosion. Field application of amendments without destroying the vegetation cover (grassland) involved two approaches: (a) slurrying (Slu) the amendments into cut gaps in the vegetation cover and (b) injecting (Inj) the amendments through the vegetation cover. Here, we investigate the immobilising and long-term efficiency of treatments [gravel sludge (2.5%) + red mud (0.5%) (GS + RM)]. Risk assessment was based on soil, plant and water samples taken over a period of 10 years. Ammonium-nitrate-extractable Cd was reduced up to 50%, Pb up to 90%, and Zn over 90%. Plant uptake into the grass mixture and narrow leaf plantain was significantly reduced for Cd, Pb, and Zn. Harvesting early in vegetation period can further reduce uptake and meet the threshold for fodder crops. The reduction of these elements in the seepage water in 24 samplings within these 10 years reached 40%, 45% and 50%, respectively. Immobilisation increased microbial biomass and decreased human bioaccessibility for Pb. Our investigation of the long-term efficiency of GS + RM in all treatments shows that the Slu and Inj amendment application techniques have promising potential as a realistic and practical method for extensively contaminated hilly land. Slurrying performed best. We conclude that grassland remediation methods involving tillage are counterproductive from the viewpoint of bioaccessibility

  5. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    Science.gov (United States)

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  6. Human and animal health risk assessment of metal contamination in soil and plants from Ait Ammar abandoned iron mine, Morocco.

    Science.gov (United States)

    Nouri, Mohamed; Haddioui, Abdelmajid

    2016-01-01

    The goal of this paper is to investigate metal pollution in food chain and assess the resulting health risks to native citizens in Ait Ammar village. The results showed that cadmium (Cd), lead (Pb), and copper (Cu) concentrations in animal organs were above the metal concentration safety limit. Nevertheless, soils and plants from mining area were contaminated with iron (Fe), chromium (Cr), zinc (Zn), and Cr, Cu, Zn respectively. Cd concentrations in almost animal organs were higher than the acceptable daily upper limit, suggesting human consumption of this livestock meat and offal may pose a health risk. The estimated intake of Pb and Cd for Ait Ammar population could be a cause of concern because it exceeded the Provisional Tolerable Weekly Intake (PTWI) proposed by Joint Expert Committee on Food Additives (JECFA) in this area. Thus, conducting regular periodic studies to assess the dietary intake of mentioned elements are recommended.

  7. Water Table Recession in Subsurface Drained Soils

    OpenAIRE

    Moustafa, Mahmoud Mohamed; Yomota, Atsushi

    1999-01-01

    Theoretical drainage equations are intensively tested in many parts of humid and arid regions and are commonly used in drainage design. However, this is still a great concern in Japan as the drainage design is exclusively based on local experiences and empirical basis. There is a need therefore to evaluate the theoretical drainage equations under Japanese field conditions to recommend equations for design of subsurface drainage systems. This was the main motivation for this study. While drain...

  8. In Situ Evaluation of Crop Productivity and Bioaccumulation of Heavy Metals in Paddy Soils after Remediation of Metal-Contaminated Soils.

    Science.gov (United States)

    Kim, Shin Woong; Chae, Yooeun; Moon, Jongmin; Kim, Dokyung; Cui, Rongxue; An, Gyeonghyeon; Jeong, Seung-Woo; An, Youn-Joo

    2017-02-15

    Soils contaminated with heavy metals have been reused for agricultural, building, and industrial uses following remediation. This study assesses plant growth and bioaccumulation of heavy metals following remediation of industrially contaminated soil. The soil was collected from a field site near a nonferrous smelter and was subjected to laboratory- and field-scale studies. Soil from the contaminated site was remediated by washing with acid or mixed with soil taken from a distant uncontaminated site. The activities of various soil exoenzymes, the rate of plant growth, and the bioaccumulations of six heavy metals were measured to assess the efficacy of these bioremediation techniques. Growth of rice (Oryza sativa) was unaffected in acid-washed soil or the amended soil compared to untreated soil from the contaminated site. The levels of heavy metals in the rice kernels remained within safe limits in treated and untreated soils. Rice, sorghum (Sorghum bicolor), and wheat (Triticum aestivum) cultivated in the same soils in the laboratory showed similar growth rates. Soil exoenzyme activities and crop productivity were not affected by soil treatment in field experiments. In conclusion, treatment of industrially contaminated soil by acid washing or amendment did not adversely affect plant productivity or lead to increased bioaccumulation of heavy metals in rice.

  9. Contents and composition of organic matter in subsurface soils affected by land use and soil mineralogy

    Science.gov (United States)

    Ellerbrock, Ruth H.; Kaiser, Michael

    2010-05-01

    Land use and mineralogy affect the ability of surface as well as subsurface soils to sequester organic carbon and their contribution to mitigate the greenhouse effect. This study aimed to investigate the long-term impact of land use (i.e., arable and forest) and soil mineralogy on contents and composition of soil organic matter (SOM) from subsurface soils. Seven soils different in mineralogy (Albic and Haplic Luvisol, Colluvic and Haplic Regosol, Haplic and Vertic Cambisol, Haplic Stagnosol) were selected within Germany. Soil samples were taken from forest and adjacent arable sites. First, particulate and water soluble organic matter were separated from the subsurface soil samples. From the remaining solid residues the OM(PY) fractions were separated, analyzed for its OC content (OCPY) and characterized by FTIR spectroscopy. For the arable subsurface soils multiple regression analyses indicate significant positive relationships between the soil organic carbon contents and the contents of i) exchangeable Ca and oxalate soluble Fe, and Alox contents. Further for the neutral arable subsurface soils the contents OCPY weighted by its C=O contents were found to be related to the contents of Ca indicating interactions between OM(PY) and Ca cations. For the forest subsurface soils (pH <5) the OCPY contents were positively related with the contents of Na-pyrophosphate soluble Fe and Al. For the acidic forest subsurface soils such findings indicate interactions between OM(PY) and Fe3+ and Al3+ cations. The effects of land use and soil mineralogy on contents and composition of SOM and OM(PY) will be discussed.

  10. Comparisons of Soil Properties, Enzyme Activities and Microbial Communities in Heavy Metal Contaminated Bulk and Rhizosphere Soils of Robinia pseudoacacia L. in the Northern Foot of Qinling Mountain

    Directory of Open Access Journals (Sweden)

    Yurong Yang

    2017-11-01

    Full Text Available The toxic effects of heavy metal (HM contamination on plant metabolism and soil microorganisms have been emphasized recently; however, little is known about the differences in soil physical, chemical, and biological properties between bulk and rhizosphere soils contaminated with HMs in forest ecosystem. The present study was conducted to evaluate the rhizosphere effect on soil properties, enzyme activities and bacterial communities associated with Robinia pseudoacacia L. along a HM contamination gradient. Soil organic matter (SOM, available nitrogen (AN and phosphorus (AP contents were significantly higher in rhizosphere soil than those in bulk soil at HM contaminated sites (p < 0.05. Compared to bulk soil, activities of four soil enzymes indicative of C cycle (β-glucosidase, N cycle (protease, urease and P cycle (alkaline phosphatase in rhizosphere soil across all study sites increased by 47.5%, 64.1%, 52.9% and 103.8%, respectively. Quantitative PCR (qPCR and restriction fragment length polymorphism (RFLP were used to determine the relative abundance, composition and diversity of bacteria in both bulk and rhizosphere soils, respectively. The copy number of bacterial 16S rRNA gene in bulk soil was significantly lower than that in rhizosphere soil (p < 0.05, and it had significantly negative correlations with total/DTPA-extractable Pb concentrations (p < 0.01. Alphaproteobacteria, Gammaproteobacteria and Firmicutes were the most dominant groups of bacteria at different study sites. The bacterial diversity index of Species richness (S and Margalef (dMa were significantly higher in rhizosphere soil compared with those in bulk soil, although no difference could be found in Simpson index (D between bulk and rhizosphere soils (p > 0.05. Redundancy analysis (RDA results showed that soil pH, EC, SOM and total/DTPA-extractable Pb concentrations were the most important variables affecting relative abundance, composition and diversity of bacteria (p < 0

  11. Migration of radionuclides in sub-surface soil

    International Nuclear Information System (INIS)

    Bachhuber, H.; Bunzl, K.; Dietl, F.; Kretner, R.; Schimmack, W.; Schultz, W.

    1981-08-01

    The object of the investigations was to draw the most realistic conclusions about the spreading rate of the radionuclides Sr, I, Cs and Ce in a model accident contaminating the earth surface for various subsurface soils taken from the environment of the Gorleben salt done. The retardation factors were hence determined for these radionuclides in columntests in undisturbed soil samples and the distribution coefficients determined in disturbed soil samples by shaking tests (batch method). The following mobility series can be given very globally for the examined soil profiles where especially columnar-results had been used: Ranker (Trebel) J > Sr > Ce > Cs, Podsol (Gorleben) J > Cs > Sr > Ce, Braunerde (Bruenkendorf) J approx. >= Sr > Ce approx. >= Cs. Arable Soils: Podsol (Gorleben) J > Sr > Cs > Ce, Parabraunerde (Eschweiler) J > Sr > Ce approx. >= Cs. (orig./HP) [de

  12. The effects of Pantoea sp. strain Y4-4 on alfalfa in the remediation of heavy-metal-contaminated soil, and auxiliary impacts of plant residues on the remediation of saline-alkali soils.

    Science.gov (United States)

    Li, Shuhuan; Wang, Jie; Gao, Nanxiong; Liu, Lizhu; Chen, Yahua

    2017-04-01

    The plant-growth-promoting rhizobacterium (PGPR) Y4-4 was isolated from plant rhizosphere soil and identified as Pantoea sp. by 16S rRNA sequence analysis. The effects of strain Y4-4 on alfalfa grown in heavy-metals-contaminated soil was investigated using a pot experiment. In a Cu-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 22.6% and 21%, and Cu accumulation increased by 15%. In a Pb-Zn-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 23.4% and 22%, and Zn accumulation increased by 30.3%. In addition, the salt tolerance and biomass of wheat seedlings could be improved by applying strain Y4-4 mixed with plant residue as a result of the Cu-rich plant residues providing copper nutrition to wheat. This study offers an efficient PGPR with strong salt tolerance and a safe strategy for the post-treatment of plant residue.

  13. Wet–dry cycles impact DOM retention in subsurface soils

    Directory of Open Access Journals (Sweden)

    Y. Olshansky

    2018-02-01

    Full Text Available Transport and reactivity of carbon in the critical zone are highly controlled by reactions of dissolved organic matter (DOM with subsurface soils, including adsorption, transformation and exchange. These reactions are dependent on frequent wet–dry cycles common to the unsaturated zone, particularly in semi-arid regions. To test for an effect of wet–dry cycles on DOM interaction and stabilization in subsoils, samples were collected from subsurface (Bw horizons of an Entisol and an Alfisol from the Catalina-Jemez Critical Zone Observatory and sequentially reacted (four batch steps with DOM extracted from the corresponding soil litter layers. Between each reaction step, soils either were allowed to air dry (wet–dry treatment before introduction of the following DOM solution or were maintained under constant wetness (continually wet treatment. Microbial degradation was the dominant mechanism of DOM loss from solution for the Entisol subsoil, which had higher initial organic C content, whereas sorptive retention predominated in the lower C Alfisol subsoil. For a given soil, bulk dissolved organic C losses from solution were similar across treatments. However, a combination of Fourier transform infrared (FTIR and near-edge X-ray absorption fine structure (NEXAFS spectroscopic analyses revealed that wet–dry treatments enhanced the interactions between carboxyl functional groups and soil particle surfaces. Scanning transmission X-ray microscopy (STXM data suggested that cation bridging by Ca2+ was the primary mechanism for carboxyl association with soil surfaces. STXM data also showed that spatial fractionation of adsorbed OM on soil organo-mineral surfaces was diminished relative to what might be inferred from previously published observations pertaining to DOM fractionation on reaction with specimen mineral phases. This study provides direct evidence of the role of wet–dry cycles in affecting sorption reactions of DOM to a complex soil

  14. Wet-dry cycles impact DOM retention in subsurface soils

    Science.gov (United States)

    Olshansky, Yaniv; Root, Robert A.; Chorover, Jon

    2018-02-01

    Transport and reactivity of carbon in the critical zone are highly controlled by reactions of dissolved organic matter (DOM) with subsurface soils, including adsorption, transformation and exchange. These reactions are dependent on frequent wet-dry cycles common to the unsaturated zone, particularly in semi-arid regions. To test for an effect of wet-dry cycles on DOM interaction and stabilization in subsoils, samples were collected from subsurface (Bw) horizons of an Entisol and an Alfisol from the Catalina-Jemez Critical Zone Observatory and sequentially reacted (four batch steps) with DOM extracted from the corresponding soil litter layers. Between each reaction step, soils either were allowed to air dry (wet-dry treatment) before introduction of the following DOM solution or were maintained under constant wetness (continually wet treatment). Microbial degradation was the dominant mechanism of DOM loss from solution for the Entisol subsoil, which had higher initial organic C content, whereas sorptive retention predominated in the lower C Alfisol subsoil. For a given soil, bulk dissolved organic C losses from solution were similar across treatments. However, a combination of Fourier transform infrared (FTIR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopic analyses revealed that wet-dry treatments enhanced the interactions between carboxyl functional groups and soil particle surfaces. Scanning transmission X-ray microscopy (STXM) data suggested that cation bridging by Ca2+ was the primary mechanism for carboxyl association with soil surfaces. STXM data also showed that spatial fractionation of adsorbed OM on soil organo-mineral surfaces was diminished relative to what might be inferred from previously published observations pertaining to DOM fractionation on reaction with specimen mineral phases. This study provides direct evidence of the role of wet-dry cycles in affecting sorption reactions of DOM to a complex soil matrix. In the soil

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

  17. 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

  18. Metal contamination in environmental media in residential ...

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

    1995-05-01

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

  20. Heavy metal contamination characteristic of soil in WEEE (waste electrical and electronic equipment) dismantling community: a case study of Bangkok, Thailand.

    Science.gov (United States)

    Damrongsiri, Seelawut; Vassanadumrongdee, Sujitra; Tanwattana, Puntita

    2016-09-01

    Sue Yai Utit is an old community located in Bangkok, Thailand which dismantles waste electrical and electronic equipment (WEEE). The surface soil samples at the dismantling site were contaminated with copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) higher than Dutch Standards, especially around the WEEE dumps. Residual fractions of Cu, Pb, Zn, and Ni in coarse soil particles were greater than in finer soil. However, those metals bonded to Fe-Mn oxides were considerably greater in fine soil particles. The distribution of Zn in the mobile fraction and a higher concentration in finer soil particles indicated its readily leachable character. The concentration of Cu, Pb, and Ni in both fine and coarse soil particles was mostly not significantly different. The fractionation of heavy metals at this dismantling site was comparable to the background. The contamination characteristics differed from pollution by other sources, which generally demonstrated the magnification of the non-residual fraction. A distribution pathway was proposed whereby contamination began by the deposition of WEEE scrap directly onto the soil surface as a source of heavy metal. This then accumulated, corroded, and was released via natural processes, becoming redistributed among the soil material. Therefore, the concentrations of both the residual and non-residual fractions of heavy metals in WEEE-contaminated soil increased.

  1. Microbial competition, lack in macronutrients, and acidity as main obstacles to the transfer of basidiomycetous ground fungi into (organically or heavy-metal contaminated) soils.

    Science.gov (United States)

    Gramss, Gerhard; Bergmann, Hans

    2007-08-01

    Non-symbiotic soil microorganisms which have been expensively engineered or selected to support plant nutrition, control root diseases, degrade xenobiotic hydrocarbons, and repress or stimulate heavy metal uptake of plants fail to survive in target soils. This prompted studies into the role of chemistry and microbial pre-colonization of 23 top soils in long-term growth of basidiomycetes. Fungi are seen as auxiliary agents in soil remediation. Untreated soils (1.5 L) were colonized by lignocellulose preferring ground fungi such as Agaricus aestivalis, A. bisporus, A. campestris, A. edulis, A. macrocarpus, A. porphyrizon, Agrocybe dura, A. praecox, Clitocybe sp., Coprinus comatus, Lepista nuda, L. sordida, Macrolepiota excoriata, M. procera, Stropharia coronilla, and S. rugoso-annulata. Spawn mycelia of fairy-ring-type fungi such as Agaricus arvensis, A. fissuratus, A. langei, A. lanipes, A. pilatianus, Lyophyllum sp., and Marasmius oreades died back in contact with non-sterile soils. Fungal growth correlated positively with the soils' Ct Ca K Mg content and negatively with microbial CO2 evolution. Pasteurization and autoclaving increased mycelial growth and life span in soils pH 6.6-8.2. Growth of pH-sensitive but not of pH-tolerant fungi was inhibited on the Ca-deficient soils pH 4-4.4 (-5.6) and was not improved by autoclaving. The pretended fungistasis of acid soils to pH-sensitive fungi was controlled by N P K mineral (pH not altering) or organic (pH increasing) fertilizing as well as by neutralization with NaOH or CaCO3. Although microbial competition was mortal to 33% of the fungal mycelia inserted into natural unplanted soils, further seriously antifungal effects beyond those pretended by low pH conditions and shortage in mineral macronutrients were not identified.

  2. A Rapid, Accurate, and Efficient Method to Map Heavy Metal-Contaminated Soils of Abandoned Mine Sites Using Converted Portable XRF Data and GIS

    Directory of Open Access Journals (Sweden)

    Jangwon Suh

    2016-12-01

    Full Text Available The use of portable X-ray fluorescence (PXRF and inductively coupled plasma atomic emission spectrometry (ICP-AES increases the rapidity and accuracy of soil contamination mapping, respectively. In practice, it is often necessary to repeat the soil contamination assessment and mapping procedure several times during soil management within a limited budget. In this study, we have developed a rapid, inexpensive, and accurate soil contamination mapping method using a PXRF data and geostatistical spatial interpolation. To obtain a large quantity of high quality data for interpolation, in situ PXRF data analyzed at 40 points were transformed to converted PXRF data using the correlation between PXRF and ICP-AES data. The method was applied to an abandoned mine site in Korea to generate a soil contamination map for copper and was validated for investigation speed and prediction accuracy. As a result, regions that required soil remediation were identified. Our method significantly shortened the time required for mapping compared to the conventional mapping method and provided copper concentration estimates with high accuracy similar to those measured by ICP-AES. Therefore, our method is an effective way of mapping soil contamination if we consistently construct a database based on the correlation between PXRF and ICP-AES data.

  3. The enchytraeid reproduction test (ERT): A potentially quick and affordable tool for the assessment of metal contaminated soils in emerging economies.

    Science.gov (United States)

    Voua Otomo, Patricks; Wahl, Jurie; Maboeta, Mark S

    2013-11-01

    The enchytraeid reproduction test (ERT) was used to assess the ecotoxicity of selected mine tailings and agricultural soils from South Africa. The mine tailings had higher cumulative metal concentrations than agricultural soils. The most contaminated mine tailings significantly reduced the survival of the oligochaete Enchytraeus doerjesi whose reproduction was suppressed in all mine waste substrates. Because it reliably singled out the most contaminated substrate and was found easy to perform, we suggest that the ERT could be a quick and affordable tool for assigning intervention values for soil remediation in emerging economies such as South Africa.

  4. Application of EDTA decontamination on soils affected by mining activities and impact of treatment on the geochemical partition of metal contaminants.

    Science.gov (United States)

    Xia, Wenbin; Gao, Hui; Wang, Xianhai; Zhou, Chunhua; Liu, Yunguo; Fan, Ting; Wang, Xin

    2009-05-30

    Two soil samples were collected at mining areas located in southern Hunan Province, China. EDTA extraction of Pb, Zn, Cu and Cd from these two tailing soils was studied using column leaching experiments. The redistributions of heavy metals (HMs) were determined using the modified BCR (Community Bureau of Reference) sequential extraction procedure, before and after EDTA extraction. The results indicated that EDTA was an effective extractant because of its strong chelating ability for various HMs. The proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA of the acid-extractable fraction (AEX) was significant in shallow soil column, while in deeper soil column, decrease of the extraction efficiency of reduced (RED), oxidizable (OX) and residual fractions (RES) was obtained, which was mainly due to the decrease of EDTA concentration.

  5. Comparison of the ability of organic acids and EDTA to enhance the phytoextraction of metals from a multi-metal contaminated soil.

    Science.gov (United States)

    Kim, Sung-Hyun; Lee, In-Sook

    2010-02-01

    Chelates have been shown to enhance the phytoextraction of metal from contaminated soil. In this study, we evaluated the ability of chelates to enhance the phytoextraction of metals by barnyard grass (Echinochloa crus-galli) from soils contaminated with multiple metals. The results revealed that EDTA increased the ability of barnyard grass to take up Cd, Cu and Pb, but that it resulted in increased soil leaching. Conversely, citric acid induced the removal of Cd, Cu and Pb from soil without increasing the risk of leaching. Furthermore, E.crus-galli showed no signs of phytotoxicity in response to treatment with citric acid, whereas its shoot growth decreased in response to treatment with EDTA (p acid is a good agent for the enhancement of the phytoextraction of metals.

  6. Characterization of Cd-, Pb-, Zn-resistant endophytic Lasiodiplodia sp. MXSF31 from metal accumulating Portulaca oleracea and its potential in promoting the growth of rape in metal-contaminated soils.

    Science.gov (United States)

    Deng, Zujun; Zhang, Renduo; Shi, Yang; Hu, Li'ao; Tan, Hongming; Cao, Lixiang

    2014-02-01

    The aim of this study was to characterize the features of a Cd-, Pb-, and Zn-resistant endophytic fungus Lasiodiplodia sp. MXSF31 and to investigate the potential of MXSF31 to remove metals from contaminated water and soils. The endophytic fungus was isolated from the stem of Portulaca oleracea growing in metal-contaminated soils. The maximum biosorption capacities of MXSF31 were 3.0 × 10(3), 1.1 × 10(4), and 1.3 × 10(4) mg kg(-1) for Cd, Pb, and Zn, respectively. The biosorption processes of Cd, Pb, and Zn by MXSF31 were well characterized with the pseudo-second-order kinetic model. The biosorption isotherm processes of Pb and Zn by the fungus were fitted better with the Langmuir model, while the biosorption processes of Cd was better fitted with the Freundlich model. The biosorption process of MXSF31 was attributed to the functional groups of hydroxyl, amino, carbonyl, and benzene ring on the cell wall. The active biomass of the strain removed more Cd, Pb, and Zn (4.6 × 10(4), 5.6 × 10(5), and 7.0 × 10(4) mg kg(-1), respectively) than the dead biomass. The inoculation of MXSF31 increased the biomass of rape (Brassica napus L.), the translocation factor of Cd, and the extraction amount of Cd by rape in the Cd+Pb-contaminated soils. The results indicated that the endophytic fungus strain had the potential to remove heavy metals from water and soils contaminated by multiple heavy metals, and plants accumulating multiple metals might harbor diverse fungi suitable for bioremediation of contaminated media.

  7. [Risk Assessment of Heavy Metal Contamination in Farmland Soil in Du'an Autonomous County of Guangxi Zhuang Autonomous Region, China].

    Science.gov (United States)

    Wu, Yang; Yang, Jun; Zhou, Xiao-yong; Lei, Mei; Gao, Ding; Qiao, Peng-wei; Du, Guo-dong

    2015-08-01

    For a comprehensive understanding of the pollution characteristics and ecological risk of heavy metals of farmland soil in Du'an Autonomous County of Guangxi Zhuang Autonomous Region, China, this study evaluated the cadmium (Cd), arsenic (As), nickel (Ni), zinc (Zn), chromium (Cr), antimony (Sb), copper (Cu) and lead ( Pb) pollution situation using the single factor index, the Nemerow pollution index and the Hakanson ecological risk index. The results showed that heavy-metal pollution of farmland soil in Du'an County was serious. 74.6% of the soil samples had heavy metals concentrations higher than the Grade II of National Soil Environmental Quality Standard (GB 15618-1995). The over standard rates of Cd, As, Ni, Zn, Cr, Sb, Cu, Pb were 70.6%, 42.9%, 34.9%, 19.8%, 19.6%, 2.94%, 1.59%, 0.79%, respectively. Cd and As were the main contaminants in Du'an County, the pollution was far more serious than those of the national and Guangxi Zhuang Autonomous Region. In terms of the ecological risk, heavy metals of farmland soil in Du'an County showed a "middle" ecological risk, with Cd accounting for 88% of the total ecological risk. The north-west of Jiudu Town and the zone between Bao'an Town and Dongmiao Town were two areas with high ecological risk in Du'an County. The contamination of farmland soils in Du'an County was caused by two main sources, whereas the pollution of As and Sb of farmland soils near Diaojiang River was mainly caused by the upstream mining industry.

  8. Integrating EDDS-enhanced washing with low-cost stabilization of metal-contaminated soil from an e-waste recycling site.

    Science.gov (United States)

    Beiyuan, Jingzi; Tsang, Daniel C W; Ok, Yong Sik; Zhang, Weihua; Yang, Xin; Baek, Kitae; Li, Xiang-Dong

    2016-09-01

    While chelant-enhanced soil washing has been widely studied for metal extraction from contaminated soils, there are concerns about destabilization and leaching of residual metals after remediation. This study integrated 2-h soil washing enhanced by biodegradable ethylenediaminedisuccinic acid (EDDS) and 2-month stabilization using agricultural waste product (soybean stover biochar pyrolyzed at 300 and 700 °C), industrial by-product (coal fly ash (CFA)), and their mixture. After integration with 2-month stabilization, the leachability and mobility of residual metals (Cu, Zn, and Pb) in the field-contaminated soil were significantly reduced, especially for Cu, in comparison with 2-h EDDS washing alone. This suggested that the metals destabilized by EDDS-washing could be immobilized by subsequent stabilization with biochar and CFA. Moreover, when the remediation performance was evaluated for phytoavailability and bioaccessibility, prior EDDS washing helped to achieve a greater reduction in the bioavailable fraction of metals than sole stabilization treatment. This was probably because the weakly-bound metals were first removed by EDDS washing before stabilization. Both individual and combined applications of biochar and CFA showed comparable effectiveness regardless of the difference in material properties, possibly due to the high level of amendments (150 ton ha(-1)). Based on the mobility and bioaccessibility results, the estimated human health risk (primarily resulting from Pb) could be mitigated to an acceptable level in water consumption pathway or reduced by half in soil ingestion pathway. These results suggest that an integration of EDDS washing with soil stabilization can alleviate post-remediation impacts of residual metals in the treated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Risk Assessment of Heavy Metals Contamination in Paddy Soil, Plants, and Grains (Oryza sativa L.) at the East Coast of India

    Science.gov (United States)

    Satpathy, Deepmala; Reddy, M. Vikram; Dhal, Soumya Prakash

    2014-01-01

    Heavy metals known to be accumulated in plants adversely affect human health. This study aims to assess the effects of agrochemicals especially chemical fertilizers applied in paddy fields, which release potential toxic heavy metals into soil. Those heavy metals get accumulated in different parts of paddy plant (Oryza sativa L.) including the grains. Concentrations of nonessential toxic heavy metals (Cd, Cr, and Pb) and the micronutrients (Cu, Mn, and Zn) were measured in the paddy field soil and plant parts. Mn and Cd are found to be accumulated more in shoot than in root. The metal transfer factors from soil to rice plant were significant for Pb, Cd, Cu, Cr, Mn, and Zn. The ranking order of bioaccumulation factor (BAF) for heavy metals was Zn > Mn > Cd > Cu > Cr > Pb indicating that the accumulation of micronutrients was more than that of nonessential toxic heavy metals. The concentrations of heavy metals were found to be higher in paddy field soils than that of the nearby control soil but below permissible limits. The higher Health Index (HI) values of rice consuming adults (1.561) and children (1.360) suggest their adverse health effects in the near future. PMID:24995308

  10. 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.

  11. Ecological and human health risk assessment of heavy metal contamination in soil of a municipal solid waste dump in Uyo, Nigeria.

    Science.gov (United States)

    Ihedioha, J N; Ukoha, P O; Ekere, N R

    2017-06-01

    The study assessed the levels of some heavy metals in soils in the vicinity of a municipal solid waste dumpsite with a view to providing information on the extent of contamination, ecological risk of metals in the soils and human health risk to the residents in Uyo. Soil samples were collected in rainy and dry seasons and analyzed for metals (Pb, Cd, Zn, Mn, Cr, Ni and Fe) using atomic absorption spectrometry. The concentrations of heavy metals (mg/kg) at the dumpsite in rainy season were Pb (9.90), Zn (137), Ni (12.56), Cr (3.60), Cd (9.05) and Mn (94.00), while in dry season, the concentrations were Pb (11.80), Zn (146), Ni (11.82), Cr (4.05), Cd (12.20) and Mn (91.20). The concentrations of metals in the studied sites were higher than that of the control site (P contamination than adult.

  12. Effect of Miscanthus cultivation on metal fractionation and human bioaccessibility in metal-contaminated soils: comparison between greenhouse and field experiments.

    Science.gov (United States)

    Pelfrêne, Aurélie; Kleckerová, Andrea; Pourrut, Bertrand; Nsanganwimana, Florien; Douay, Francis; Waterlot, Christophe

    2015-02-01

    The in situ stabilization of metals in soils using plants with great biomass value is a promising, cost-effective, and ecologically friendly alternative to manage metal-polluted sites. The goal of phytostabilization is to reduce the bioavailable concentrations of metals in polluted soil and thus reduce the risk to the environment and human health. In this context, this study aimed at evaluating Miscanthus × giganteus efficiency in phytostabilizing metals on three contaminated agricultural sites after short-term exposure under greenhouse conditions and after long-term exposure under field conditions. Particular attention was paid to the influence of Miscanthus cultivation on (i) Cd, Pb, and Zn fractionation using sequential extractions and (ii) metal bioaccessibility using an in vitro gastrointestinal digestion test. Data gave evidence of (i) different behaviors between the greenhouse and the field; (ii) metal redistribution in soils induced by Miscanthus culture, more specifically under field conditions; (iii) higher environmental availability for Cd than for Pb and Zn was found in both conditions; and (iv) overall, a higher bioaccessible fraction for Pb (about 80 %) and Cd (65-77 %) than for Zn (36-52 %) was recorded in the gastric phase, with a sharp decrease in the intestinal phase (18-35 % for Cd, 5-30 % for Pb, and 36-52 % for Zn). Compared to soils without culture, the results showed that phytostabilization using Miscanthus culture provided evidence for substantial effects on oral bioaccessibility of Cd, Pb, and Zn.

  13. Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

    DEFF Research Database (Denmark)

    Zheng, Shixue; Su, Jing; Wang, Liang

    2014-01-01

    impacted cellular growth and subsequent resistance to multiple heavy metal(loid)s. Conclusions: C. testosteroni S44 could be very useful for bioremediation in heavy metal(loid) polluted soils due to the ability to both reduce toxic Se(VI) and Se(IV) to non-toxic Se (0) under aerobic conditions...

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

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Lü, Ce

    2014-02-01

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

  15. Bait-lamina assay as a tool to assess the effects of metal contamination in the feeding activity of soil invertebrates within a uranium mine area

    International Nuclear Information System (INIS)

    Andre, A.; Antunes, S.C.; Goncalves, F.; Pereira, R.

    2009-01-01

    As part of the tier 2 of a site-specific risk assessment, this study was the first reporting an intensive in situ application of the bait-lamina assay; two exposure periods (7 and 14 days) were tested during four seasons in ten different sites, within a uranium mine area and at two different depths. The most contaminated sites (by deposition of sludge from the effluent treatment pond) were discriminated after 14 days of exposure because extremely low percentages of feeding activity were recorded. Previous sub-lethal ecotoxicological assays, already had demonstrated that the habitat function of these soils is compromised. Nevertheless, seasonality has proved to have a significant influence on responses. Thus to strength conclusions about the impact of contaminants, the in situ bait-lamina assay should be performed on different annual seasons, at least for temperate regions. It was also found that some environmental parameters (e.g. soil moisture and litter) can act as confounding factors in the bait-lamina assay. - Bait-lamina assay for in situ evaluation of soil functions under site-specific risk assessments.

  16. Effects of metal-contaminated soils on the accumulation of heavy metals in gotu kola (Centella asiatica) and the potential health risks: a study in Peninsular Malaysia.

    Science.gov (United States)

    Ong, Ghim Hock; Wong, Ling Shing; Tan, Ai Li; Yap, Chee Kong

    2016-01-01

    Centella asiatica is a commonly used medicinal plant in Malaysia. As heavy metal accumulation in medicinal plants which are highly consumed by human is a serious issue, thus the assessment of heavy metals in C. asiatica is important for the safety of consumers. In this study, the heavy metal accumulation in C. asiatica and the potential health risks were investigated. Samples of C. asiatica and surface soils were collected from nine different sites around Peninsular Malaysia. The concentration of six heavy metals namely Cd, Cu, Ni, Fe, Pb and Zn were determined by air-acetylene flame atomic absorption spectrophotometer (AAS). The degree of anthropogenic influence was assessed by calculating the enrichment factor (EF) and index of geoaccumulation (Igeo). The heavy metal uptake into the plant was estimated through the calculation of translocation factor (TF), bioconcentration factor (BCF) and correlation study. Estimated daily intakes (EDI) and target hazard quotients (THQ) were used to determine the potential health risk of consuming C. asiatica. The results showed that the overall surface soil was polluted by Cd, Cu and Pb, while the uptake of Zn and Ni by the plants was high. The value of EDI and THQ showed that the potential of Pb toxicity in C. asiatica was high as well. As heavy metal accumulation was confirmed in C. asiatica, daily consumption of the plant derived from polluted sites in Malaysia was not recommended.

  17. 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.

  18. Heavy metal contamination in soil, food crops and associated health risks for residents of Ropar wetland, Punjab, India and its environs.

    Science.gov (United States)

    Sharma, Sakshi; Nagpal, Avinash Kaur; Kaur, Inderpreet

    2018-07-30

    In the present study, an assessment of heavy metal content in soil and food crops (wheat, rice, maize grains and mustard seeds) and associated health risks was carried out for residents of Ropar wetland and its environs. All the soil samples had high cadmium and cobalt contents, whereas, all crop samples had high contents of cobalt and lead. Bioconcentration factor (BCF) analysis indicated that rice grains act as hyper-accumulators of chromium (BCF = 17.98) and copper (BCF = 10.91), whereas, maize grains act as hyper-accumulators of copper (BCF = 30.43). One-way ANOVA suggested that heavy metal content in food crops varied significantly at p ≤ 0.05 for different sites, indicating anthropogenic contribution of heavy metals in agricultural fields. Dietary intake of cobalt via all food crops posed higher non-cancer health risk to residents in comparison to other heavy metals. Chromium posed highest cancer risk through consumption of wheat grains, being staple diet in study area. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Stabilization and reuse of heavy metal contaminated soils by means of quicklime sulfate salt treatment. Final report, September 1992--February 1995

    International Nuclear Information System (INIS)

    Dermatas, D.

    1995-08-01

    Capillary and hydraulic flows of water in porous media contaminated by heavy metal species often result in severe aquifer contamination. In the present study a chemical admixture stabilization approach is proposed, where heavy metal stabilization/immobilization is achieved by means of quicklime-based treatment. Both in-situ treatment by injection and on-site stabilization by excavation, mixing, and compaction will be investigated. In addition, the potential to reuse the resulting stabilized material as readily available construction material will also be investigated. The heavy metals under study include: arsenic, chromium, lead, and mercury. The proposed technical approach consists of three separate phases. During phase A, both artificial and naturally occurring contaminated soil mixes were treated, and then tested for stress-strain properties, leachability, micromorphology, mineralogical composition, permeability, setting time, and durability. In such a way, the effectiveness of the proposed remediation technology was verified, the treatment approach was optimized, and the underlying mechanisms responsible for stabilization were established. During phase B, the proposed technology will be tested for two DOE-site subscale systems, involving naturally occurring contaminated soil, using the same testing methodology as the one outlined for phase A. Provided that the proposed technology is proven effective for the subscale systems, a field application will be demonstrated. Again process quality monitoring will be performed by testing undisturbed samples collected from the treated sites, in the same fashion as for the previous phases. Following completion of the proposed study, a set of comprehensive guidelines for field applications will be developed. 42 refs., 196 figs., 26 tabs

  20. Metal Contamination in the Republic of Armenia.

    Science.gov (United States)

    Kurkjian

    2000-05-01

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

  1. Residues of endosulfan in surface and subsurface agricultural soil and its bioremediation.

    Science.gov (United States)

    Odukkathil, Greeshma; Vasudevan, Namasivayam

    2016-01-01

    The persistence of many hydrophobic pesticides has been reported by various workers in various soil environments and its bioremediation is a major concern due to less bioavailability. In the present study, the pesticide residues in the surface and subsurface soil in an area of intense agricultural activity in Pakkam Village of Thiruvallur District, Tamilnadu, India, and its bioremediation using a novel bacterial consortium was investigated. Surface (0-15 cm) and subsurface soils (15-30 cm and 30-40 cm) were sampled, and pesticides in different layers of the soil were analyzed. Alpha endosulfan and beta endosulfan concentrations ranged from 1.42 to 3.4 mg/g and 1.28-3.1 mg/g in the surface soil, 0.6-1.4 mg/g and 0.3-0.6 mg/g in the subsurface soil (15-30 cm), and 0.9-1.5 mg/g and 0.34-1.3 mg/g in the subsurface soil (30-40 cm) respectively. Residues of other persistent pesticides were also detected in minor concentrations. These soil layers were subjected to bioremediation using a novel bacterial consortium under a simulated soil profile condition in a soil reactor. The complete removal of alpha and beta endosulfan was observed over 25 days. Residues of endosulfate were also detected during bioremediation, which was subsequently degraded on the 30th day. This study revealed the existence of endosulfan in the surface and subsurface soils and also proved that the removal of such a ubiquitous pesticide in the surface and subsurface environment can be achieved in the field by bioaugumenting a biosurfactant-producing bacterial consortium that degrades pesticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Crescimento e teor de metais de mudas de espécies arbóreas cultivadas em solo contaminado com metais pesados Growth and metal concentration of seedlings of woody species in a heavy metal contaminated soil

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Lara Lanza de Sá e Melo Marques

    2000-01-01

    Full Text Available O objetivo do trabalho foi avaliar o teor de metais pesados e o crescimento de mudas de 20 espécies arbóreas tropicais em solo com elevado grau de contaminação com metais pesados. Em casa de vegetação, as mudas foram transplantadas para vasos contendo 3,3 kg de misturas com diferentes proporções (0, 20, 40 e 60% v/v de solo contaminado. Verificou-se comportamento diferenciado das espécies quanto à inibição de crescimento e aos teores de metais na raiz e na parte aérea em decorrência da contaminação. Com base na produção de matéria seca da parte aérea, concluiu-se que apenas Myrsine umbellata, Cedrella fissilis, Tabebuia impetiginosa e Copaifera langsdorffii não foram afetadas pela contaminação, enquanto Hymenaea courbaril, Mimosa caesalpiniaefolia, Acacia mangium e Platypodium gonoacantha sofreram pequeno impacto. As demais espécies foram muito inibidas pela contaminação do solo, o que é causado pela absorção, na maioria dos casos, de Zn e Cd. Várias espécies apresentaram elevada capacidade de reter esses metais nas raízes, evitando sua translocação para a parte aérea.The objective of the paper was to evaluate metal content and ability to grow in soil with excess of heavy metals of seedlings of 20 woody species. In the greenhouse, seedlings were transplanted to pots with 3.3 kg of soil-mixes with different proportions (0, 20, 40, 60% v/v of a heavy metal contaminated soil. It was found that plant species behaved differently in terms of growth inhibition and metal content in the shoots and roots. Based upon the dry matter yield, only Myrsine umbellata, Cedrella fissilis, Tabebuia impetiginosa and Copaifera langsdorffii were not affected by increasing contamination, whereas Hymenaea courbaril, Mimosa caesalpiniaefolia, Acacia mangium and Platypodium gonoacantha were only slightly affected by it. All the other species were highly inhibited by the excess of metals in the soil, being such effects related, in most

  3. Using lagged dependence to identify (de)coupled surface and subsurface soil moisture values

    Science.gov (United States)

    Carranza, Coleen D. U.; van der Ploeg, Martine J.; Torfs, Paul J. J. F.

    2018-04-01

    Recent advances in radar remote sensing popularized the mapping of surface soil moisture at different spatial scales. Surface soil moisture measurements are used in combination with hydrological models to determine subsurface soil moisture values. However, variability of soil moisture across the soil column is important for estimating depth-integrated values, as decoupling between surface and subsurface can occur. In this study, we employ new methods to investigate the occurrence of (de)coupling between surface and subsurface soil moisture. Using time series datasets, lagged dependence was incorporated in assessing (de)coupling with the idea that surface soil moisture conditions will be reflected at the subsurface after a certain delay. The main approach involves the application of a distributed-lag nonlinear model (DLNM) to simultaneously represent both the functional relation and the lag structure in the time series. The results of an exploratory analysis using residuals from a fitted loess function serve as a posteriori information to determine (de)coupled values. Both methods allow for a range of (de)coupled soil moisture values to be quantified. Results provide new insights into the decoupled range as its occurrence among the sites investigated is not limited to dry conditions.

  4. Predicting Subsurface Soil Layering and Landslide Risk with Artificial Neural Networks

    DEFF Research Database (Denmark)

    Farrokhzad, Farzad; Barari, Amin; Ibsen, Lars Bo

    2011-01-01

    This paper is concerned principally with the application of ANN model in geotechnical engineering. In particular the application for subsurface soil layering and landslide analysis is discussed in more detail. Three ANN models are trained using the required geotechnical data obtained from...... networks are capable of predicting variations in the soil profile and assessing the landslide hazard with an acceptable level of confidence....

  5. Carbon mineralization in surface and subsurface soils in a subtropical mixed forest in central China

    Science.gov (United States)

    Liu, F.; Tian, Q.

    2014-12-01

    About a half of soil carbon is stored in subsurface soil horizons, their dynamics have the potential to significantly affect carbon balancing in terrestrial ecosystems. However, the main factors regulating subsurface soil carbon mineralization are poorly understood. As affected by mountain humid monsoon, the subtropical mountains in central China has an annual precipitation of about 2000 mm, which causes strong leaching of ions and nutrition. The objectives of this study were to monitor subsurface soil carbon mineralization and to determine if it is affected by nutrient limitation. We collected soil samples (up to 1 m deep) at three locations in a small watershed with three soil layers (0-10 cm, 10-30 cm, below 30 cm). For the three layers, soil organic carbon (SOC) ranged from 35.8 to 94.4 mg g-1, total nitrogen ranged from 3.51 to 8.03 mg g-1, microbial biomass carbon (MBC) ranged from 170.6 to 718.4 μg g-1 soil. We measured carbon mineralization with the addition of N (100 μg N/g soil), P (50 μg P/g soil), and liable carbon (glucose labeled by 5 atom% 13C, at five levels: control, 10% MBC, 50% MBC, 100% MBC, 200% MBC). The addition of N and P had negligible effects on CO2 production in surface soil layers; in the deepest soil layer, the addition of N and P decreased CO2 production from 4.32 to 3.20 μg C g-1 soil carbon h-1. Glucose addition stimulated both surface and subsurface microbial mineralization of SOC, causing priming effects. With the increase of glucose addition rate from 10% to 200% MBC, the primed mineralization rate increased from 0.19 to 3.20 μg C g-1 soil carbon h-1 (fifth day of glucose addition). The magnitude of priming effect increased from 28% to 120% as soil layers go deep compare to the basal CO2 production (fifth day of 200% MBC glucose addition, basal CO2 production rate for the surface and the deepest soil was 11.17 and 2.88 μg C g-1 soil carbon h-1). These results suggested that the mineralization of subsurface carbon is more

  6. Application of in situ vitrification in the soil subsurface: Engineering-scale testing

    International Nuclear Information System (INIS)

    Luey, J.; Seiler, D.K.

    1995-03-01

    Engineering-scale testing to evaluate the initiation and propagation of the in situ vitrification (ISV) process in the soil subsurface has been completed. Application of ISV in the soil subsurface both increases the applicable treatment depth (beyond a demonstrated 5 m) and allows treatment of local contamination, such as liquid seepage trenches (found on many US Department of Energy sites) that were designed to remove contamination at the bottom of the trench. The following observations and conclusions resulted from the test data: the ISV process can be initiated in the soil subsurface and propagated in both vertical directions, with the downward direction providing greater ease of operation; energy efficiency to process a kilogram of soil was 20% better than for an ISV melt initiated at the soil surface, increased efficiency was attributed to insulation from the soil overburden; the feasibility of initiating the process with a planar starter path was confirmed, thus increasing the number of options for initiating the process in the field; soil subsidence was pronounced and requires attention before field demonstration of subsurface ISV. Further field work at pilot-scale is recommended for this new ISV application. The key step will be the placement of starter material at depth to initiate the process

  7. The soil classification and the subsurface carbon stock estimation with a ground-penetrating radar

    International Nuclear Information System (INIS)

    Onishi, K.; Rokugawa, S.; Kato, Y.

    2002-01-01

    One of the serious problems of the Kyoto Protocol is that we have no effective method to estimate the carbon stock of the subsurface. To solve this problem, we propose the application of ground-penetrating radar (GPR) to the subsurface soil survey. As a result, it is shown that GPR can detect the soil horizons, stones and roots. The fluctuations of the soil horizons in the forest are cleanly indicated as the reflection pattern of the microwaves. Considering the fact that the physical, chemical, and biological characteristics of each soil layer is almost unique, GPR results can be used to estimate the carbon stock in soil by combining with the vertical soil sample survey at one site. Then as a trial, we demonstrate to estimate the carbon content fixed in soil layers based on the soil samples and GPR survey data. we also compare this result with the carbon stock for the flat horizon case. The advantages of GPR usage for this object are not only the reduction of uncertainty and the cost, but also the environmental friendliness of survey manner. Finally, we summarize the adaptabilities of various antennas having different predominant frequencies for the shallow subsurface zone. (author)

  8. Potential impact of soil microbial heterogeneity on the persistence of hydrocarbons in contaminated subsurface soils.

    Science.gov (United States)

    Aleer, Sam; Adetutu, Eric M; Weber, John; Ball, Andrew S; Juhasz, Albert L

    2014-04-01

    In situ bioremediation is potentially a cost effective treatment strategy for subsurface soils contaminated with petroleum hydrocarbons, however, limited information is available regarding the impact of soil spatial heterogeneity on bioremediation efficacy. In this study, we assessed issues associated with hydrocarbon biodegradation and soil spatial heterogeneity (samples designated as FTF 1, 5 and 8) from a site in which in situ bioremediation was proposed for hydrocarbon removal. Test pit activities showed similarities in FTF soil profiles with elevated hydrocarbon concentrations detected in all soils at 2 m below ground surface. However, PCR-DGGE-based cluster analysis showed that the bacterial community in FTF 5 (at 2 m) was substantially different (53% dissimilar) and 2-3 fold more diverse than communities in FTF 1 and 8 (with 80% similarity). When hydrocarbon degrading potential was assessed, differences were observed in the extent of (14)C-benzene mineralisation under aerobic conditions with FTF 5 exhibiting the highest hydrocarbon removal potential compared to FTF 1 and 8. Further analysis indicated that the FTF 5 microbial community was substantially different from other FTF samples and dominated by putative hydrocarbon degraders belonging to Pseudomonads, Xanthomonads and Enterobacteria. However, hydrocarbon removal in FTF 5 under anaerobic conditions with nitrate and sulphate electron acceptors was limited suggesting that aerobic conditions were crucial for hydrocarbon removal. This study highlights the importance of assessing available microbial capacity prior to bioremediation and shows that the site's spatial heterogeneity can adversely affect the success of in situ bioremediation unless area-specific optimizations are performed. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

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

  10. Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils.

    Science.gov (United States)

    Unno, Yusuke; Tsukada, Hirofumi; Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun'ichi

    2017-04-01

    We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I - was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I - K d middle layer (i.e., with high radioiodide retention ability) differed between sites. K d of 125 I - was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I - . Further study is needed to clarify how radioiodide is retained and migrates in soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Subsurface earthworm casts can be important soil microsites specifically influencing the growth of grassland plants.

    Science.gov (United States)

    Zaller, Johann G; Wechselberger, Katharina F; Gorfer, Markus; Hann, Patrick; Frank, Thomas; Wanek, Wolfgang; Drapela, Thomas

    Earthworms (Annelida: Oligochaeta) deposit several tons per hectare of casts enriched in nutrients and/or arbuscular mycorrhizal fungi (AMF) and create a spatial and temporal soil heterogeneity that can play a role in structuring plant communities. However, while we begin to understand the role of surface casts, it is still unclear to what extent plants utilize subsurface casts. We conducted a greenhouse experiment using large mesocosms (volume 45 l) to test whether (1) soil microsites consisting of earthworm casts with or without AMF (four Glomus taxa) affect the biomass production of 11 grassland plant species comprising the three functional groups grasses, forbs, and legumes, (2) different ecological groups of earthworms (soil dwellers- Aporrectodea caliginosa vs. vertical burrowers- Lumbricus terrestris ) alter potential influences of soil microsites (i.e., four earthworms × two subsurface microsites × two AMF treatments). Soil microsites were artificially inserted in a 25-cm depth, and afterwards, plant species were sown in a regular pattern; the experiment ran for 6 months. Our results show that minute amounts of subsurface casts (0.89 g kg -1 soil) decreased the shoot and root production of forbs and legumes, but not that of grasses. The presence of earthworms reduced root biomass of grasses only. Our data also suggest that subsurface casts provide microsites from which root AMF colonization can start. Ecological groups of earthworms did not differ in their effects on plant production or AMF distribution. Taken together, these findings suggest that subsurface earthworm casts might play a role in structuring plant communities by specifically affecting the growth of certain functional groups of plants.

  12. Characteristics of Nitrogen Loss through Surface-Subsurface Flow on Red Soil Slopes of Southeast China

    Science.gov (United States)

    Zheng, Haijin; Liu, Zhao; Zuo, Jichao; Wang, Lingyun; Nie, Xiaofei

    2017-12-01

    Soil nitrogen (N) loss related to surface flow and subsurface flow (including interflow and groundwater flow) from slope lands is a global issue. A lysimetric experiment with three types of land cover (grass cover, GC; litter cover, LC; and bare land, BL) were carried out on a red soil slope land in southeast China. Total Nitrogen (TN) loss through surface flow, interflow and groundwater flow was observed under 28 natural precipitation events from 2015 to 2016. TN concentrations from subsurface flow on BL and LC plots were, on average, 2.7-8.2 and 1.5-4.4 times greater than TN concentrations from surface flow, respectively; the average concentration of TN from subsurface flow on GC was about 36-56% of that recorded from surface flow. Surface flow, interflow and groundwater flow contributed 0-15, 2-9 and 76-96%, respectively, of loss load of TN. Compared with BL, GC and LC intercepted 83-86% of TN loss through surface runoff; GC intercepted 95% of TN loss through subsurface flow while TN loss through subsurface flow on LC is 2.3 times larger than that on BL. In conclusion, subsurface flow especially groundwater flow is the dominant hydrological rout for N loss that is usually underestimated. Grass cover has the high retention of N runoff loss while litter mulch will increase N leaching loss. These findings provide scientific support to control N runoff loss from the red soil slope lands by using suitable vegetation cover and mulching techniques.

  13. Variability of soil potential for biodegradation of petroleum hydrocarbons in a heterogeneous subsurface

    DEFF Research Database (Denmark)

    Kristensen, Andreas Houlberg; Poulsen, Tjalfe; Mortensen, Lars

    2010-01-01

    for biodegradation was highly variable, which from autoregressive state-space modeling was partly explained by changes in soil air-filled porosity and gravimetric water content. The results suggest considering biological heterogeneity when evaluating the fate of contaminants in the subsurface.......Quantifying the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone is important to (i) performing a reliable risk assessment and (ii) evaluating the possibility for bioremediation of petroleum-polluted sites. Most studies to date have focused...... on the shallow unsaturated zone. Based on a data set comprising analysis of about 100 soil samples taken in a 16-m-deep unsaturated zone polluted with volatile petroleum compounds, we statistically and geostatistically analyzed values of essential soil properties. The subsurface of the site was highly layered...

  14. Numerical solution of the transport equation describing the radon transport from subsurface soil to buildings

    International Nuclear Information System (INIS)

    Savovic, S.; Djordjevich, A.; Ristic, G.

    2012-01-01

    A theoretical evaluation of the properties and processes affecting the radon transport from subsurface soil into buildings is presented in this work. The solution of the relevant transport equation is obtained using the explicit finite difference method (EFDM). Results are compared with analytical steady-state solution reported in the literature. Good agreement is found. It is shown that EFDM is effective and accurate for solving the equation that describes radon diffusion, advection and decay during its transport from subsurface to buildings, which is especially important when arbitrary initial and boundary conditions are required. (authors)

  15. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen G.; Jensen, Karsten Høgh

    1998-01-01

    disturbance and compaction of the soil surface. Hypothetically introducing fully surface-connected macropores into the calibrated model resulted in a 22% increase in the loss of solute to the drain, indicating the significance of the hydraulic conditions at the soil surface and the model specification thereof......The experimental results from a field-scale tracer experiment in a subsurface-drained glacial till soil were analyzed by the application of a single/dual porosity model (MACRO), optionally accounting for concurrent and interacting flow and transport in the bulk soil porosity as well...... concentration. The exchange was overpredicted and too rapid when the soil aggregate size (distance between macropores) obtained from an image analysis of soil cores was used in the model. On this basis, the model assumption of instant equilibration of the solute across the matrix porosity, disregarding small...

  16. Subsurface Characterization using Geophysical Seismic Refraction Survey for Slope Stabilization Design with Soil Nailing

    Science.gov (United States)

    Ashraf Mohamad Ismail, Mohd; Ng, Soon Min; Hazreek Zainal Abidin, Mohd; Madun, Aziman

    2018-04-01

    The application of geophysical seismic refraction for slope stabilization design using soil nailing method was demonstrated in this study. The potential weak layer of the study area is first identify prior to determining the appropriate length and location of the soil nail. A total of 7 seismic refraction survey lines were conducted at the study area with standard procedures. The refraction data were then analyzed by using the Pickwin and Plotrefa computer software package to obtain the seismic velocity profiles distribution. These results were correlated with the complementary borehole data to interpret the subsurface profile of the study area. It has been identified that layer 1 to 3 is the potential weak zone susceptible to slope failure. Hence, soil nails should be installed to transfer the tensile load from the less stable layer 3 to the more stable layer 4. The soil-nail interaction will provide a reinforcing action to the soil mass thereby increasing the stability of the slope.

  17. Nocturnal soil CO2 uptake and its relationship to sub-surface soil and ecosystem carbon fluxes in a Chihuahuan Desert shrubland

    Science.gov (United States)

    Despite their prevalence, little attention has been given to quantifying aridland soil and ecosystem carbon fluxes over prolonged, annually occurring dry periods. We measured surface soil respiration (Rsoil), volumetric soil moisture and temperature in inter- and under-canopy soils, sub-surface soi...

  18. Integration of Magnetic and Geotechnical methods for Shallow Subsurface Soil Characterization at Sungai Batu, Kedah, Malaysia

    Science.gov (United States)

    Samuel, Y. M.; Saad, R.; Muztaza, N. M.; Saidin, M. M.; Muhammad, S. B.

    2018-04-01

    Magnetic and geotechnical methods were used for shallow subsurface soil characterization at Sungai Batu, Kedah, (Malaysia). Ground magnetic data were collected along a survey line of length 160 m long at 2 m constant station spacing, while soil drilling using hand auger was conducted at 21 m on the survey line using 0.2 m sampling interval drilled to a depth of 5 m. Result from the processed magnetic profile data shows distribution of magnetic residuals in the range of -4.55 to 1.61 nT, with magnetic low (-4.55 nT to -0.058 nT) and were identified at distances 4 m, 10 to 16 m, 20 to 26 m, 58 m, 82 m, 104 to 106 m, 118 m, and 124 to 140 m. The magnetic lows are attributes of sediments. The result from the soil drilling shows sticky samples with variable sizes, greyish to brownish / reddish in colour, and some of the samples show the presence of shiny and black spots. The characteristics of the samples suggest the soil as a by-product of completely weathered rock; weak with high water content and classified as Grade V soil. The study concludes; integration of geophysical and geotechnical methods aided in characterizing the subsurface soil at Sungai Batu. The result was correlated with previous studies and confirms the importance of integrated approach in minimising ambiguity in interpretation.

  19. Nitrogen isotope ratios in surface and sub-surface soil horizons

    International Nuclear Information System (INIS)

    Rennie, D.A.; Paul, E.A.

    1975-01-01

    Nitrogen isotope analysis of surface soils and soil-derived nitrate for selected chernozemic and luvisolic soils showed mean delta 15 N values of 11.7 and 11.3, respectively. Isotope enrichment of the total N reached a maximum in the lower B horizon. Sub-soil parent material samples from the one deep profile included in the study indicated a delta 15 N value (NO 3 -N) of 1/3 that of the Ap horizon, at a depth of 180 cm. The delta 15 N of sub-surface soil horizons containing residual fertilizer N were low (-2.2) compared to the surface horizon (9.9). The data reported from this preliminary survey suggest that the natural variations in 15 N abundance between different soils and horizons of the same soil reflect the cumulative effects of soil genesis and soil management. More detailed knowledge and understanding of biological and other processes which control N isotope concentrations in these soils must be obtained before the data reported can be interpreted. (author)

  20. Microbial colonisation in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota

    Science.gov (United States)

    Marteinsson, V.; Klonowski, A.; Reynisson, E.; Vannier, P.; Sigurdsson, B. D.; Ólafsson, M.

    2014-09-01

    Colonisation of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focusing on settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associate vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soils types on the surface of the island. Total viable bacterial counts were performed with plate count at 22, 30 and 37 °C for all soils samples and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms aerobic and anaerobic bacteria. The deep subsurface biosphere was investigated by collecting liquid subsurface samples from a 182 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between N deficits and the number of microorganisms in surface soils samples. The lowest number of bacteria (1 × 104-1 × 105 g-1) was detected in almost pure pumice but the count was significant higher (1 × 106-1 × 109 g-1) in vegetated soil or pumice with bird droppings. The number of faecal bacteria correlated also to the total number of bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in vegetated and samples containing bird droppings. The human pathogens Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S rDNA sequences were found in the subsurface samples collected at 145 m and 172 m depth at 80 °C and 54 °C, respectively, but no growth was observed in enrichments. The microbiota sequences generally showed low affiliation to any known 16S rRNA gene sequences.

  1. Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota

    Science.gov (United States)

    Marteinsson, V.; Klonowski, A.; Reynisson, E.; Vannier, P.; Sigurdsson, B. D.; Ólafsson, M.

    2015-02-01

    Colonization of life on Surtsey has been observed systematically since the formation of the island 50 years ago. Although the first colonisers were prokaryotes, such as bacteria and blue-green algae, most studies have been focused on the settlement of plants and animals but less on microbial succession. To explore microbial colonization in diverse soils and the influence of associated vegetation and birds on numbers of environmental bacteria, we collected 45 samples from different soil types on the surface of the island. Total viable bacterial counts were performed with the plate count method at 22, 30 and 37 °C for all soil samples, and the amount of organic matter and nitrogen (N) was measured. Selected samples were also tested for coliforms, faecal coliforms and aerobic and anaerobic bacteria. The subsurface biosphere was investigated by collecting liquid subsurface samples from a 181 m borehole with a special sampler. Diversity analysis of uncultivated biota in samples was performed by 16S rRNA gene sequences analysis and cultivation. Correlation was observed between nutrient deficits and the number of microorganisms in surface soil samples. The lowest number of bacteria (1 × 104-1 × 105 cells g-1) was detected in almost pure pumice but the count was significantly higher (1 × 106-1 × 109 cells g-1) in vegetated soil or pumice with bird droppings. The number of faecal bacteria correlated also to the total number of bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in vegetated samples and samples containing bird droppings. The human pathogens Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S rDNA sequences were found in the subsurface samples collected at 145 and 172 m depth at 80 and 54 °C, respectively, but no growth was observed in enrichments. The microbiota sequences generally showed low affiliation to any known 16S rRNA gene sequences.

  2. Frozen Soil Barrier. Subsurface Contaminants Focus Area. OST Reference No. 51

    International Nuclear Information System (INIS)

    1999-01-01

    Problem: Hazardous and radioactive materials have historically been disposed of at the surface during operations at Department of Energy facilities. These contaminants have entered the subsurface, contaminating soils and groundwater resources. Remediation of these groundwater plumes using the baseline technology of pump and treat is expensive and takes a long time to complete. Containment of these groundwater plumes can be alternative or an addition to the remediation activities. Standard containment technologies include slurry walls, sheet piling, and grouting. These are permanent structures that once installed are difficult to remove. How It Works: Frozen Soil Barrier technology provides a containment alternative, with the key difference being that the barrier can be easily removed after a period of time, such as after the remediation or removal of the source is completed. Frozen Soil Barrier technology can be used to isolate and control the migration of underground radioactive or other hazardous contaminants subject to transport by groundwater flow. Frozen Soil Barrier technology consists of a series of subsurface heat transfer devices, known as thermoprobes, which are installed around a contaminant source and function to freeze the soil pore water. The barrier can easily be maintained in place until remediation or removal of the contaminants is complete, at which time the barrier is allowed to thaw.

  3. Subsurface cadmium loss from a stony soil-effect of cow urine application.

    Science.gov (United States)

    Gray, Colin William; Chrystal, Jane Marie; Monaghan, Ross Martin; Cavanagh, Jo-Anne

    2017-05-01

    Cadmium (Cd) losses in subsurface flow from stony soils that have received cow urine are potentially important, but poorly understood. This study investigated Cd loss from a soil under a winter dairy-grazed forage crop that was grazed either conventionally (24 h) or with restricted grazing (6 h). This provided an opportunity to test the hypothesis that urine inputs could increase Cd concentrations in drainage. It was thought this would be a result of cow urine either (i) enhancing dissolved organic carbon (DOC) concentrations via an increase in soil pH, resulting in the formation of soluble Cd-organic carbon complexes and, or (ii) greater inputs of chloride (Cl) via cow urine, promoting the formation of soluble Cd-Cl complexes. Cadmium concentrations in subsurface flow were generally low, with a spike above the water quality guidelines for a month after the 24-h grazing. Cadmium fluxes were on average 0.30 g Cd ha -1  year -1 (0.27-0.32 g Cd ha -1  year -1 ), in line with previous estimates for agricultural soils. The mean Cd concentration in drainage from the 24-h grazed plots was significantly higher (P soil. Further study is warranted to confirm the mechanisms involved and quantities of Cd lost from other systems.

  4. The influence of surface incorporated lime and gypsiferous by-products on surface and subsurface soil acidity. I. Soil solution chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.L.; Hedley, M.J.; Bolan, N.S.; Horne, D.J. [New Zealand Forest Research Institute, Rotorua (New Zealand)

    1999-04-01

    Lime, fluidised bed boiler ash (FBA) and flue gas desulfurisation gypsum (FGDG) were incorporated in the top 50 mm of repacked columns of either an Allophanic (the Patua sand loam) or an Ultic (the Kaawa clay loam) soil, at rates containing calcium equivalent to 5000 kg/ha of CaCO{sub 3}. After leaching with water, the columns were sliced into sections for chemical analysis. In the columns of the variable-charged, allophanic Patua soil, topsoil-incorporated FBA ameliorated top and subsurface soil acidity through liming and the `self liming effect` induced by sulfate sorption, respectively. The soil solution pH of the top and subsurface layers of the Patua soil were raised to pH 6.40 and 5.35, respectively, by the FBA treatment. Consequently , phytotoxic labile monomeric aluminium (Al) concentration in the soil solution of the FBA treatment was reduced to {lt} 0.1 {mu}M Al. FGDG had a similar `self-liming effect` on subsurface of the Patua soil, but not the topsoil. Whereas FBA raised the pH of the Kaawa topsoil, no `self-liming effect` of subsurface soil by sulfate sorption was observed on the Kaawa subsurface soil, which is dominated by permanently charged clay minerals. Application of FBA and FGDG to both soils, however, caused significantly leaching of native soil Mg{sup 2+} and K{sup +}.

  5. Soil, climate and the environment - an indissociable threesome. Soil carbon and global changes: reciprocal impacts; Carbon in all its forms; Echomicadas, a new tool to analyse carbon 14; Biotransformation of metallic trace elements by soil micro-organisms; Absorption and distribution of metallic elements in plants; Dynamics of metallic contaminants in agricultural systems; Is photo-remediation for tomorrow? Hyper-accumulator plants; Sediments, tell me the Seine history... The complex history of plant feeding by the soil; The environmental analysis

    International Nuclear Information System (INIS)

    Hatte, Christine; Tisnerat-Laborde, Nadine; Ayrault, Sophie; Balesdent, Jerome; Chapon, Virginie; Bourguignon, Jacques; Alban, Claude; Ravanel, Stephane; Denaix, Laurence; Nguyen, Christophe; Vavasseur, Alain; Sarrobert, Catherine; Gasperi, Johnny; Latrille, Christelle; Savoye, Sebastien; Augusto, Laurent; Conan Labbe, Annie; Bernard Michel, Bruno; Douysset, Guilhem; Toqnelli, Antoine; Vailhen, Dominique; Moulin, Christophe

    2016-01-01

    The articles of this file on the relationships between soils, climate and the environment discuss the reciprocal impacts of soil carbon and global changes with the objective of reduction of greenhouse effect and of increase of carbon sequestration; the various forms of carbon are presented and their properties commented ; a compact radiocarbon system (ECHoMiCADAS) is presented, developed by the Laboratory of sciences of climate and environment (LSCE) and designed for the analysis of carbon 14; an article describes how micro-organisms can play a crucial role in the transformation of soil pollutants by modifying their chemical speciation and thus their toxicity; strategies based on the absorption of metallic trace elements present in the soil to control physiological processes in plants are discussed, with applications to agriculture, food supply and to the environment; researches related to the study of effects of metallic contaminants in agricultural systems are evoked, and the reasons for a slow development of phyto-technologies, notably phyto-remediation, for pollution control and decontamination of soils and liquid media, are explained. Other themes are presented : hyper-accumulator plants which present very high contents of non-essential (As, Cd, Hg, Pb, Se) or essential (Co, Cu, Fe, Mn, Mo, Ni) elements, are slowly growing, and display a limited biomass, but could be used for a phyto-extraction of metals from contaminated soils; how analysis and dating of sediments can reveal the presence of contaminants, and therefore give an insight into human activities and regulations, and into their impact on the river; how plants are able to develop strategies in their search for nutrients in different types of soils, even poor ones, and presentation of the various disciplines, methods and techniques used for environmental analysis with their applications to installation and site control, or to the study of pollutant migration

  6. In situ mapping of radionuclides in subsurface and surface soils: 1994 Summary report

    International Nuclear Information System (INIS)

    Schilk, A.J.; Hubbard, C.W.; Knopf, M.A.; Abel, K.H.

    1995-04-01

    Uranium production and support facilities at several DOE sites occasionally caused local contamination of some surface and subsurface soils. The thorough cleanup of these sites is a major public concern and a high priority for the US Department of Energy, but before any effective remedial protocols can be established, the three-dimensional distributions of target contaminants must be characterized. Traditional means of measuring radionuclide activities in soil are cumbersome, expensive, time-consuming, and often do not accurately reflect conditions over very large areas. New technologies must be developed, or existing ones improved, to allow cheaper, faster, and safer characterization of radionuclides in soils at these sites. The Pacific Northwest Laboratory (PNL) was tasked with adapting, developing, and demonstrating technologies to measure uranium in surface and subsurface soils. In partial completion of this effort, PNL developed an improved in situ gamma-ray spectrometry system to satisfy the technical requirements. This document summarizes fiscal-year 1994 efforts at PNL to fulfill requirements for TTP number-sign 321103 (project number-sign 19307). These requirements included (a) developing a user-friendly software package for reducing field-acquired gamma-ray spectra, (b) constructing an improved data-acquisition hardware system for use with high-purity germanium detectors, (c) ensuring readiness to conduct field mapping exercises as specified by the sponsor, (d) evaluating the in situ gamma-ray spectrometer for the determination of uranium depth distribution, and (e) documenting these efforts

  7. Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation

    Science.gov (United States)

    Fan, Wangtao; Li, Gang

    2018-02-01

    Subsurface drip irrigation (SDI) is a technique that has a high potential in application because of its high efficiency in water-saving. The hydraulic characteristics of SDI sub-unit pipe network can be affected by soil physical properties as the emitters are buried in soils. The related research, however, is not fully explored. The laboratory tests were carried out in the present study to determine the effects of hydraulic factors including operating pressure, initial soil water content, and bulk density on flow rate and its sensitivity to each hydraulic factor for two types of SDI emitters (PLASSIM emitter and Heping emitter). For this purpose, three soils with contrasting textures (i.e., light sand, silt loam, and light clay) were repacked with two soil bulk density (1.25 and1.40 g cm-3) with two initial soil water content (12% and 18%) in plexiglass columns with 40 cm in diameter and 40 cm in height. Drip emitters were buried at depth of 20 cm to measure the flow rates under seven operating pressures (60, 100, 150, 200, 250, 300, and 370 kPa). We found that the operating pressure was the dominating factor of flow rate of the SDI emitter, and flow rate increased with the increase of operating pressure. The initial soil water content and bulk density also affected the flow rate, and their effects were the most notable in the light sand soil. The sensitivity of flow rate to each hydraulic factor was dependent on soil texture, and followed a descending order of light sand>silt loam>light clay for both types of emitters. Further, the sensitivity of flow rate to each hydraulic factor decreased with the increase of operating pressure, initial soil water content, and bulk density. This study may be used to guide the soil specific-design of SDI emitters for optimal water use and management.

  8. Study of heavy metal contamination in river floodplains using the red-edge position in spectroscopic data

    NARCIS (Netherlands)

    Clevers, J.G.P.W.; Kooistra, L.; Salas, E.A.L.

    2004-01-01

    One of the major environmental problems resulting from the regular flooding of rivers in Europe is the heavy metal contamination of soils. Various studies have shown that soil contamination may influence plant physiology and, through changes in leaf pigment concentrations, influence reflectance

  9. Effect of subsurface drainage on salt movement and distribution in salt-affected soils

    International Nuclear Information System (INIS)

    Moustafa, A.T.A.; Seliem, M.H.; Bakhati, H.K.

    1983-01-01

    This study was carried out to evaluate different subsurface drainage treatments (combinations of depth and spacing) on salt movement and distribution. The soil is clay and the drainage was designed according to the steady-state condition (Hooghoudt's equation). Three spacings and two depths resulted in six drainage treatments. Soil samples represented the initial state of every treatment and after 14 months they (cotton followed by wheat) were analysed. The data show that drain depth has its effective role in salt leaching, while drain spacing has its effect on salt distribution in the soil profile. The leaching rate of each specific ion is also affected by the different drainage treatments. In general, the salt movement and distribution should be taken into consideration when evaluating the design of drainage systems. (author)

  10. Statistical Analysis of Nitrogen in the Soil of Constructed Wetland with Horizontal Sub-Surface Flow

    Directory of Open Access Journals (Sweden)

    Jakubaszek Anita

    2014-06-01

    Full Text Available The removal of nitrogen compounds in constructed wetlands depends on various physical, chemical and biomechanical factors as well as on conditions of the environment. The paper presents the results of a statistical analysis of the depositing of nitrogen at HSSF (horizontal subsurface flow construcred wetland. The results of the substrate showed that the highest contents of nitrogen existed in the surface soil layer up to 20 cm of the depth. Nitrogen accumulation decreased in the deposit with depth, and in the direction of the wastewater flow.

  11. A Subsurface Soil Composition and Physical Properties Experiment to Address Mars Regolith Stratigraphy

    Science.gov (United States)

    Richter, L.; Sims, M.; Economou, T.; Stoker, C.; Wright, I.; Tokano, T.

    2004-01-01

    Previous in-situ measurements of soil-like materials on the surface of Mars, in particular during the on-going Mars Exploration Rover missions, have shown complex relationships between composition, exposure to the surface environment, texture, and local rocks. In particular, a diversity in both compositional and physical properties could be established that is interpreted to be diagnostic of the complex geologic history of the martian surface layer. Physical and chemical properties vary laterally and vertically, providing insight into the composition of rocks from which soils derive, and environmental conditions that led to soil formation. They are central to understanding whether habitable environments existed on Mars in the distant past. An instrument the Mole for Soil Compositional Studies and Sampling (MOCSS) - is proposed to allow repeated access to subsurface regolith on Mars to depths of up to 1.5 meters for in-situ measurements of elemental composition and of physical and thermophysical properties, as well as for subsurface sample acquisition. MOCSS is based on the compact PLUTO (PLanetary Underground TOol) Mole system developed for the Beagle 2 lander and incorporates a small X-ray fluorescence spectrometer within the Mole which is a new development. Overall MOCSS mass is approximately 1.4 kilograms. Taken together, the MOCSS science data support to decipher the geologic history at the landing site as compositional and textural stratigraphy if they exist - can be detected at a number of places if the MOCSS were accommodated on a rover such as MSL. Based on uncovered stratigraphy, the regional sequence of depositional and erosional styles can be constrained which has an impact on understanding the ancient history of the Martian near-surface layer, considering estimates of Mars soil production rates of 0.5... 1.0 meters per billion years on the one hand and Mole subsurface access capability of approximately 1.5 meters. An overview of the MOCSS, XRS

  12. The Development of a Sub-Surface Monitoring System for Organic Contamination in Soils and Groundwater

    Directory of Open Access Journals (Sweden)

    Sharon L. Huntley

    2002-01-01

    Full Text Available A major problem when dealing with environmental contamination is the early detection and subsequent surveillance of the contamination. This paper describes the potential of sub-surface sensor technology for the early detection of organic contaminants in contaminated soils, sediments, and landfill sites. Rugged, low-power hydrocarbon sensors have been developed, along with a data-logging system, for the early detection of phase hydrocarbons in soil. Through laboratory-based evaluation, the ability of this system to monitor organic contamination in water-based systems is being evaluated. When used in conjunction with specific immunoassays, this can provide a sensitive and low-cost solution for long-term monitoring and analysis, applicable to a wide range of field applications.

  13. Use of Microtremor Array Recordings for Mapping Subsurface Soil Structure, Singapore

    Science.gov (United States)

    Walling, M.

    2012-12-01

    Microtremor array recordings are carried out in Singapore, for different geology, to study the influence of each site in modeling the subsurface structure. The Spatial Autocorrelation (SPAC) method is utilized for the computation of the soil profiles. The array configuration of the recording consists of 7 seismometers, recording the vertical component of the ground motion, and the recording at each site is carried out for 30 minutes. The results from the analysis show that the soil structure modeled for the young alluvial of Kallang Formation (KF), in terms of shear wave velocity (Vs), gives a good correlation with borehole information, while for the older geological formation of Jurong Formation (JF) (sedimentary rock sequence) and Old Alluvial (OA) (dense alluvium formation), the correlation is not very clear due to the lack of impedance contrast. The older formation of Bukit Timah Granite (BTG) show contrasting results within the formation, with the northern BTG suggesting a low Vs upper layer of about 20m - 30m while the southern BTG reveals a dense formation. The discrepancy in the variation within BTG is confirmed from borehole data that reveals the northern BTG to have undergone intense weathering while the southern BTG have not undergone noticeable weathering. Few sites with bad recording quality could not resolve the soil structure. Microtremor array recording is good for mapping sites with soft soil formation and weathered rock formation but can be limited in the absence of subsurface velocity contrast and bad quality of microtremor records.; The correlation between the Vs30 estimated from SPAC method and borehole data for the four major geological formations of Singapore. The encircled sites are the sites with recording error.

  14. 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.

  15. Heavy metal contamination in bats in Britain

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  16. Heavy metal contamination in bats in Britain

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-15

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

  17. Spatial variation in herbicide leaching from a marine clay soil via subsurface drains

    Science.gov (United States)

    Ulén, Barbro M; Larsbo, Mats; Kreuger, Jenny K; Svanbäck, Annika

    2013-01-01

    Background Subsurface transport via tile drains can significantly contribute to pesticide contamination of surface waters. The spatial variation in subsurface leaching of normally applied herbicides was examined together with phosphorus losses in 24 experimental plots with water sampled flow-proportionally. The study site was a flat, tile-drained area with 60% marine clay in the topsoil in southeast Sweden. The objectives were to quantify the leaching of frequently used herbicides from a tile drained cracking clay soil and to evaluate the variation in leaching within the experimental area and relate this to topsoil management practices (tillage method and structure liming). Results In summer 2009, 0.14, 0.22 and 1.62%, respectively, of simultaneously applied amounts of MCPA, fluroxypyr and clopyralid were leached by heavy rain five days after spraying. In summer 2011, on average 0.70% of applied bentazone was leached by short bursts of intensive rain 12 days after application. Peak flow concentrations for 50% of the treated area for MCPA and 33% for bentazone exceeded the Swedish no-effect guideline values for aquatic ecosystems. Approximately 0.08% of the glyphosate applied was leached in dissolved form in the winters of 2008/2009 and 2010/2011. Based on measurements of glyphosate in particulate form, total glyphosate losses were twice as high (0.16%) in the second winter. The spatial inter-plot variation was large (72–115%) for all five herbicides studied, despite small variations (25%) in water discharge. Conclusions The study shows the importance of local scale soil transport properties for herbicide leaching in cracking clay soils. © 2013 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:23658148

  18. The Effects of Subsurface Bioremediation on Soil Structure, Colloid Formation, and Contaminant Transport

    Science.gov (United States)

    Wang, Y.; Liang, X.; Zhuang, J.; Radosevich, M.

    2016-12-01

    Anaerobic bioremediation is widely applied to create anaerobic subsurface conditions designed to stimulate microorganisms that degrade organic contaminants and immobilize toxic metals in situ. Anaerobic conditions that accompany such techniques also promotes microbially mediated Fe(III)-oxide mineral reduction. The reduction of Fe(III) could potentially cause soil structure breakdown, formation of clay colloids, and alternation of soil surface chemical properties. These processes could then affect bioremediation and the migration of contaminants. Column experiments were conducted to investigate the impact of anaerobic bioreduction on soil structure, hydraulic properties, colloid formation, and transport of three tracers (bromide, DFBA, and silica shelled silver nanoparticles). Columns packed with inoculated water stable soil aggregates were placed in anaerobic glovebox, and artificial groundwater media was pumped into the columns to simulate anaerobic bioreduction process for four weeks. Decent amount of soluble Fe(II) accompanied by colloids were detected in the effluent from bioreduction columns a week after initiation of bioreduction treatment, which demonstrated bioreduction of Fe(III) and formation of colloids. Transport experiments were performed in the columns before and after bioreduction process to assess the changes of hydraulic and surface chemical properties through bioreduction treatment. Earlier breakthrough of bromide and DFBA after treatment indicated alterations in flow paths (formation of preferential flow paths). Less dispersion of bromide and DFBA, and less tailing of DFBA after treatment implied breakdown of soil aggregates. Dramatically enhanced transport and early breakthrough of silica shelled silver nanoparticles after treatment supported the above conclusion of alterations in flow paths, and indicated changes of soil surface chemical properties.

  19. Transport of contaminants from energy-process-waste leachates through subsurface soils and soil components: laboratory experiments

    International Nuclear Information System (INIS)

    Wangen, L.E.; Stallings, E.A.; Walker, R.D.

    1982-08-01

    The subsurface transport and attenuation of inorganic contaminants common to a variety of energy process waste leachates are being studied using laboratory column methods. Anionic species currently being emphasized are As, B, Mo, and Se. Transport of the cations Cd and Ni is also being studied. The solid adsorbents consist of three soil mineral components (silica sand, kaolinite, and goethite), and four subsurface soils (a dunal sand, an oxidic sandy clay loam, an acidic clay loam, and an alkaline clay loam). Breakthrough patterns of these species from packed soil columns are followed by monitoring eluent concentrations vs time under carefully controlled laboratory conditions. This report describes the experimental methods being used, the results of preliminary batch adsorption studies, and the results of column experiments completed through calendar year 1981. Using column influent concentrations of about 10 mg/l, adsorption (mmoles/100 g) has been determined from the eluent volume corresponding to 50% breakthrough. On silica sand, kaolinite, dunal sand, and goethite, respectively, these are 2.0 x 10 -4 , 0.020, 0.013, and 0.31 for cadmium, 4.4 x 10 -4 , 0.039, 0.020, and 0.98 for nickel. On kaolinite, dunal sand, and goethite, respectively, adsorption values (mmoles/100 g) are As (0.24, 0.019, and 20.5), B (0.041, 0.0019, and 1.77), Mo (0.048, 0.0010, and 5.93), and Se (0.029, 0.00048, and 1.30). Arsenic is the most highly adsorbed contaminant species and goethite has the largest adsorption capacity of the adsorbents

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

    African Journals Online (AJOL)

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

  1. Microbial investigations in city soils of different use and heavy metal contamination with a view to characterizing its functional capability. Mikrobielle Untersuchungen in Stadtboeden unterschiedlicher Nutzung und Schwermetallbelastung zur Charakterisierung der Bodenfunktionalitaet

    Energy Technology Data Exchange (ETDEWEB)

    Weritz, N

    1990-11-20

    This work investigates the microbiological situation of city soils as an indicator of the soils' functional capability, and their impairment due to heavy metal pollution. It gives a survey of the literature (biological activities, influences on biological activities from heavy metals, microorganisms, bacteria, fungi, enzyme activities, CO{sub 2} respiration, mechanisms of resistance, simulation effects), points out the area of investigation and the investigated plots, and describes the method adapted. The latter includes sampling and sample storage, soil-chemical and soil-biological methods, laboratory experiments and statistical evaluation. The investigation results, which are reported in detail, cover, inter alia, the following: pH value, CaCO{sub 3} contents, cation exchange capacity, carbon content, catalase activity, urease activity and the relative comparison of microbial activity between the types of use. Results relating to heavy metal contents cover the total content and the effect of heavy metal pollutions on substrate-induced respiration, catalase activity and xylanase activity. (HWJ).

  2. HEAVY METALS CONTAMINATION OF TOPSOIL AND ...

    African Journals Online (AJOL)

    a

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

  3. Metal contamination in wildlife living near two zinc smelters

    Science.gov (United States)

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

    1985-01-01

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

  4. MATHEMATICAL AND CHEMOMETRICAL MODELS – TOOLS TO EVALUATE HEAVY METALS CONTAMINATION

    Directory of Open Access Journals (Sweden)

    Despina Maria Bordean

    2017-11-01

    Full Text Available The aim of the this study is to present a combined view of bio – geo - chemistry, soil – plant interactions, mathematic models and statistic analysis, based on the correlation between the levels of soil contamination, and the remanence of polluting substances in soil and respectively in harvested fruits and vegetables. Most of the mathematical models which describe plant - soil interactions are integrated in plant growth models or climate change models. The models presented by this paper are Soil – Plant Interaction Models, Pollution Indices, The Indices for Evaluating the Adaptative Strategies of Plants and Chemo-metrical Methods, and they have the role to synthesize and evaluate the information regarding heavy metals contamination.

  5. Combining hyperspectral imagery and legacy measured soil profiles to map subsurface soil properties in a Mediterranean area (Cap-Bon, Tunisia)

    Science.gov (United States)

    Lagacherie, Philippe; Sneep, Anne-Ruth; Gomez, Cécile

    2013-04-01

    Previous studies have demonstrated that Visible Near InfraRed (Vis-NIR) Hyperspectral imagery is a cost-efficient way for mapping soil properties at fine resolutions (~5m) over large areas. However, such mapping is only feasible for soil surface since the effective penetration depths of optical sensors do not exceed several millimetres. This study aimed to extend the use of Vis-NIR hyperspectral imagery to the mapping of subsurface properties at three intervals of depth (15-30 cm, 30-60 cm and 60-100 cm) as specified by the GlobalSoilMap project. To avoid additional data collection, our basic idea was to develop an original Digital Soil Mapping approach that combines the digital maps of surface soil properties obtained from Vis-NIR hyperspectral imagery with legacy soil profiles of the region and with easily available images of DEM-derived parameters. The study was conducted in a pedologically-contrasted 300km² cultivated area located in the Cap Bon region (Northern Tunisia). AISA-Dual Vis-NIR hyperspectral airborne data were acquired over the studied area with a fine spatial resolution (5 m) and fine spectral resolution (260 spectral bands from 450 to 2500nm). Vegetated surfaces were masked to conserve only bare soil surface which represented around 50% of the study area. Three soil surface properties (clay and sand contents, Cation Exchange Capacity) were successfully mapped over the bare soils, from these data using Partial Least Square Regression models (R2 > 0.7). We used as additional data a set of images of landscape covariates derived from a 30 meter DEM and a local database of 152 legacy soil profiles from which soil properties values at the required intervals of depths were computed using an equal-area-spline algorithm. Our Digital Soil Mapping approach followed two steps: i) the development of surface-subsurface functions - linear models and random forests - that estimates subsurface property values from surface ones and landscape covariates and that

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

    International Nuclear Information System (INIS)

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

    1993-04-01

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

  7. Radionuclide characterization of subsurface soil on the site of building 3505 at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Alexander, W.A.; Oakes, T.W.; Eldridge, J.S.; Huang, S.; Hubbard, H.M.

    1982-12-01

    Ninety-two samples at varying depths were collected from 25 cores. Sample tubes were driven into the ground and segments of soil cores were retrieved at depths from the ground surface to subsurface consolidated material. forty samples of the 92 collected had detectable gamma activities [i.e., > 2 x 10 - 2 Bq/g (0.5 pCi/g)] of 137 Cs. However, only four samples, all from the same borehole, were found to have significant amounts of 137 Cs with a maximum of 1.7 x 10 3 Bq/g (4.6 x 10 4 pCi/g). These four samples also contained the highest activities of other radionuclides ( 60 Co, 90 Sr, 235 U, 238 U, 239 Pu, and 241 Am). These subsamples came from core number 4DD, which was the deepest core collected. Core 4DD was taken at the southwest corner of the site, which is at the lower elevation of the site. Since most of the activity in this core was found below the bedrock (or shale) in the groundwater region, the contamination is probably not from Building 3505. Additional investigation in the area around core location 4DD will be required to determine the extent of contamination

  8. Episodic radon changes in subsurface soil gas along active faults and possible relation to earthquakes

    International Nuclear Information System (INIS)

    King, C.

    1980-01-01

    Subsurface soil gas along active faults in central California has been continuously monitored by the Track Etch method to test whether its radon-isotope content may show any premonitory changes useful for earthquake prediction. The monitoring network was installed in May 1975 and has since been gradually expanded to consist of more than 60 stations along a 380-km section of the San Andreas fault system between Santa Rosa and Cholame. This network has recorded several episodes, each lasting several weeks to several months, during which the radon concentration increased by a factor of approximately 2 above average along some long, but limited, fault segments (approx.100 km). These episodes occurred in different seasons and do not appear to be systematically related to changes in meteorological conditions. However, they coincided reasonably well in time and space with larger local earthquakes above a threshold magnitude of about 4.0. These episodic radon changes may be caused by a changing outgassing rate in the fault zones in response to some episodic strain changes, which incidentally caused the earthquakes

  9. Leaching of human pathogens in repacked soil lysimeters and contamination of potato tubers under subsurface drip irrigation in Denmark

    DEFF Research Database (Denmark)

    Forslund, Anita; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    The risk for contamination of potatoes and groundwater through subsurface drip irrigation with low quality water was explored in 30 large-scale lysimeters containing repacked coarse sand and sandy loam soils. The human pathogens, Salmonella Senftenberg, Campylobacter jejuni and Escherichia coli O......, phage 28B was detected in low concentrations (2 pfu ml1) in leachate from both sandy loam soil and coarse sand lysimeters. After 27 days, phage 28B continued to be present in similar concentrations in leachate from lysimeters containing coarse sand, while no phage were found in lysimeters with sandy....... The findings of bacterial pathogens and phage 28 on all potato samples suggest that the main risk associated with subsurface drip irrigation with low quality water is faecal contamination of root crops, in particular those consumed raw....

  10. Properties of Subsurface Soil Cores from Four Geologic Provinces Surrounding Mars Desert Research Station, Utah: Characterizing Analog Martian Soil in a Human Exploration Scenario

    Science.gov (United States)

    Stoker, C. R.; Clarke, J. D. A.; Direito, S.; Foing, B.

    2011-01-01

    The DOMEX program is a NASA-MMAMA funded project featuring simulations of human crews on Mars focused on science activities that involve collecting samples from the subsurface using both manual and robotic equipment methods and analyzing them in the field and post mission. A crew simulating a human mission to Mars performed activities focused on subsurface science for 2 weeks in November 2009 at Mars Desert Research Station near Hanksville, Utah --an important chemical and morphological Mars analog site. Activities performed included 1) survey of the area to identify geologic provinces, 2) obtaining soil and rock samples from each province and characterizing their mineralogy, chemistry, and biology; 3) site selection and reconnaissance for a future drilling mission; 4) deployment and testing of Mars Underground Mole, a percussive robotic soil sampling device; and 5) recording and analyzing how crew time was used to accomplish these tasks. This paper summarizes results from analysis of soil cores

  11. The perceptual trap: Experimental and modelling examples of soil moisture, hydraulic conductivity and response units in complex subsurface settings.

    Science.gov (United States)

    Jackisch, Conrad; Demand, Dominic; Allroggen, Niklas; Loritz, Ralf; Zehe, Erwin

    2017-04-01

    In order to discuss hypothesis testing in hydrology, the question of the solid foundation of such tests has to be answered. But how certain are we about our measurements of the components of the water balance and the states and dynamics of the complex systems? What implicit assumptions or bias are already embedded in our perception of the processes? How can we find light in the darkness of heterogeneity? We will contribute examples from experimental findings, modelling approaches and landscape analysis to the discussion. Example soil moisture and the soil continuum: The definition of soil moisture as fraction of water in the porous medium assumes locally well-mixed conditions. Moreover, a unique relation of soil water retention presumes instant local thermodynamic equilibrium in the pore water arrangement. We will show findings from soil moisture responses to precipitation events, from irrigation experiments, and from a model study of initial infiltration velocities. The results highlight, that the implicit assumption relating soil moisture state dynamics with actual soil water flow is biased towards the slow end of the actual velocity distribution and rather blind for preferential flow acting in a very small proportion of the pore space. Moreover, we highlight the assumption of a well-defined continuum during the extrapolation of point-scale measurements and why spatially and temporally continuous observation techniques of soil water states are essential for advancing our understanding and development of subsurface process theories. Example hydraulic conductivity: Hydraulic conductivity lies at the heart of hydrological research and modelling. Its values can range across several orders of magnitude at a single site alone. Yet, we often consider it a crisp, effective parameter. We have conducted measurements of soil hydraulic conductivity in the lab and in the field. Moreover, we assessed infiltration capacity and conducted plot-scale irrigation experiments to

  12. Heavy-metal contamination on training ranges at the Grafenwoehr Training Area, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D.; Schneider, J.F.

    1993-05-01

    Large quantities of lead and other heavy metals are deposited in the environment of weapons ranges during training exercises. This study was conducted to determine the type, degree, and extent of heavy-metal contamination on selected handgun, rifle, and hand-grenade ranges at Grafenwoehr Training Area, Germany. Soil, vegetation, and surface-water samples were collected and analyzed using the inductively-coupled plasma atomic-emission spectroscopy (ICP-AES) method and the toxic characterization leaching procedure (TCLP). The ICP-AES results show that above-normal levels of lead and copper are in the surface soil at the handgun range, high concentrations of lead and copper are in the berm and soil surface at the rifle range, and elevated levels of cadmium and above-normal concentrations of arsenic, copper, and zinc are present in the surface soil at the hand-grenade range. The TCLP results show that surface soils can be considered hazardous waste because of lead content at the rifle range and because of cadmium concentration at the hand-grenade range. Vegetation at the handgun and rifle ranges has above-normal concentrations of lead. At the hand-grenade range, both vegetation and surface water have high levels of cadmium. A hand-held X-ray fluorescence (XRF) spectrum analyzer was used to measure lead concentrations in soils in a field test of the method. Comparison of XRF readings with ICP-AES results for lead indicate that the accuracy and precision of the hand-held XRF unit must improve before the unit can be used as more than a screening tool. Results of this study show that heavy-metal contamination at all three ranges is limited to the surface soil; heavy metals are not being leached into the soil profile or transported into adjacent areas.

  13. Heavy metals contamination and human health risk assessment around Obuasi gold mine in Ghana.

    Science.gov (United States)

    Bempah, Crentsil Kofi; Ewusi, Anthony

    2016-05-01

    Gold mining has increased the prevalence and occurrence of heavy metals contamination at the Earth's surface and is causing major concern due to the potential risk involved. This study investigated the impact of gold mine on heavy metals (As, Cd, Cr, Cu, Pb, Hg, Ni, Fe, Mn, and Zn) pollution and evaluated the potential health risks to local residents via consumption of polluted groundwater, agricultural soils, and vegetable crops grown at three community farms surrounding the mine at Obuasi municipality of Ghana. The results showed levels of As, Cd, Cr, Hg, Fe, and Mn higher than the allowable drinking water standards. The vegetable samples analyzed showed high accumulation of As and Ni above the normal value. Bioaccumulation factors of heavy metals were significantly higher for vegetables grown in the Sanso soils. Estimated average daily intake and hazard quotient for As in drinking water as well as As, Pb, and Hg in vegetable samples exceeded permissible limit. Unacceptable non-cancer health risk levels were found in vegetable samples analyzed for As, Pb, and Hg. An unacceptable cancer risk was found via drinking of groundwater, in consumption of vegetables, and in soil. The hazard index for vegetables was higher than 1, indicating very high health risk to heavy metals contamination through consumption of vegetables grown around the sampling sites. The results recommend the need for regular monitoring of groundwater and food crops to protect consumers' health.

  14. Effect of the grain size of the soil on the measured activity and variation in activity in surface and subsurface soil samples

    International Nuclear Information System (INIS)

    Sulaiti, H.A.; Rega, P.H.; Bradley, D.; Dahan, N.A.; Mugren, K.A.; Dosari, M.A.

    2014-01-01

    Correlation between grain size and activity concentrations of soils and concentrations of various radionuclides in surface and subsurface soils has been measured for samples taken in the State of Qatar by gamma-spectroscopy using a high purity germanium detector. From the obtained gamma-ray spectra, the activity concentrations of the 238U (226Ra) and /sup 232/ Th (/sup 228/ Ac) natural decay series, the long-lived naturally occurring radionuclide 40 K and the fission product radionuclide 137CS have been determined. Gamma dose rate, radium equivalent, radiation hazard index and annual effective dose rates have also been estimated from these data. In order to observe the effect of grain size on the radioactivity of soil, three grain sizes were used i.e., smaller than 0.5 mm; smaller than 1 mm and greater than 0.5 mm; and smaller than 2 mm and greater than 1 mm. The weighted activity concentrations of the 238U series nuclides in 0.5-2 mm grain size of sample numbers was found to vary from 2.5:f:0.2 to 28.5+-0.5 Bq/kg, whereas, the weighted activity concentration of 4 degree K varied from 21+-4 to 188+-10 Bq/kg. The weighted activity concentrations of 238U series and 4 degree K have been found to be higher in the finest grain size. However, for the 232Th series, the activity concentrations in the 1-2 mm grain size of one sample were found to be higher than in the 0.5-1 mm grain size. In the study of surface and subsurface soil samples, the activity concentration levels of 238 U series have been found to range from 15.9+-0.3 to 24.1+-0.9 Bq/kg, in the surface soil samples (0-5 cm) and 14.5+-0.3 to 23.6+-0.5 Bq/kg in the subsurface soil samples (5-25 cm). The activity concentrations of 232Th series have been found to lie in the range 5.7+-0.2 to 13.7+-0.5 Bq/kg, in the surface soil samples (0-5 cm)and 4.1+-0.2 to 15.6+-0.3 Bq/kg in the subsurface soil samples (5-25 cm). The activity concentrations of 4 degree K were in the range 150+-8 to 290+-17 Bq/kg, in the surface

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

    African Journals Online (AJOL)

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

  16. 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.

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

    African Journals Online (AJOL)

    2016-05-27

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

  18. Concentrations of inorganic arsenic in groundwater, agricultural soils and subsurface sediments from the middle Gangetic plain of Bihar, India.

    Science.gov (United States)

    Kumar, Manoj; Ramanathan, A L; Rahman, Mohammad Mahmudur; Naidu, Ravi

    2016-12-15

    Concentrations of inorganic forms [arsenite, As(III) and arsenate, As(V) of arsenic (As) present in groundwater, agricultural soils and subsurface sediments located in the middle Gangetic plain of Bihar, India were determined. Approximately 73% of the groundwater samples (n=19) show As(III) as the dominant species while 27% reveals As(V) was the dominant species. The concentration of As(III) in agricultural soil samples varies from not detectable to 40μg/kg and As(V) was observed as the major species (ranging from 1050 to 6835μg/kg) while the total As concentration varied from 3528 to 14,690μg/kg. Total extracted concentration of As was higher in the subsurface sediments (range 9119-20,056μg/kg in Methrapur and 4788-19,681μg/kg in Harail Chapar) than the agricultural soil, indicating the subsurface sediment as a source of As. Results of X-ray diffraction (XRD) and environmental scanning electron microscope (ESEM) revealed the presence of hematite and goethite throughout the vertical section below while magnetite was observed only in the upper oxidized layer at Methrapur and Harail Chapar. Alteration of Fe-oxides and presence of fibrous goethite indicating presence of diagenetic sediment. Siderite plays a crucial role as sinks to the As in subsurface sediments. The study also concluded that decomposition of organic matter present in dark and grey sections promote the redox conditions and trigger mobilization of As into groundwater. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Study of different environmental matrices to access the extension of metal contamination along highways.

    Science.gov (United States)

    Zanello, Sônia; Melo, Vander Freitas; Nagata, Noemi

    2018-02-01

    Metals are indicators of contamination by anthropic activities, such as road traffic. To assess the extent of the metal contamination, more comprehensive studies analyzing different environmental matrices, such as soils, dust, and plants, collected in different sites that are potential sources of these pollutants along the highways, must be prioritized. Samples of soils, dust, and plants were collected alongside the highways of Brazil at 20 sites selected in strategic locations of metal accumulation (Cr, Pb, Zn, As, and Sb) or different situations of the high ways during two rain conditions (wet and dry weeks of sampling): nearby gutters and water supplies, tolls, petrol stations, a federal road police station, and areas associated with agriculture (yearly culture planting upstream of the highway). The geoaccumulation index (metal concentration in the sample of interest/background) varied from 0 to 6, and the decreasing order of contamination by metals during the wet and dry periods were, respectively: Zn > As > Pb = Sb > Cr and Zn > As > Pb > Cr > Sb. In the soils near the highways, the highest concentrations of metals were as follows (mg kg -1 ): As = 15.6, Cr = 81.9, Pb = 39.7, Sb = 5.0, and Zn = 379.3. The highest amounts of these elements in the most superficial layer in soils indicated their addition through atmospheric emissions. The most prominent metal was Sb, whose concentration was greater than the quality limits for soils. The concentration of Sb in soils was higher in the wet week than in the dry week. The emissions from road traffic promoted the increase in metals in the dust on the track, especially Zn and Pb. The highest metal concentrations in grasses (Brachiaria) were found in the roots, except for Sb and Zn, which suggests leaf absorption of atmospheric deposition. Metal contamination was widespread in all studied matrices along the highways.

  20. Remediation of heavy metal contaminated ecosystem: an overview on technology advancement

    International Nuclear Information System (INIS)

    Singh, A.; Prasad, S. M.

    2015-01-01

    The issue of heavy metal pollution is very much concerned because of their toxicity for plant, animal and human beings and their lack of biodegradability. Excess concentrations of heavy metals have adverse effect on plant metabolic activities hence affect the food production, quantitatively and qualitatively. Heavy metal when reaches human tissues through various absorption pathways such as direct ingestion, dermal contact, diet through the soil-food chain, inhalation, and oral intake may seriously affect their health. Therefore, several management practices are being applied to minimize metal toxicity by attenuating the availability of metal to the plants. Some of the traditional methods are either extremely costly or they are simply applied to isolate contaminated site. The biology based technology like use of hyper metal accumulator plants occurring naturally or created by transgenic technology, in recent years draws great attention to remediate heavy metal contamination. Recently, applications of nanoparticle for metal remediation are also attracting great research interest due to their exceptional adsorption and mechanical properties and unique electrical property, highly chemical stability, and large specific surface area. Thus the present review deals with different management approaches to reduce level of metal contamination in soil and finally to the food chain

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

    Science.gov (United States)

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

    2014-12-16

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

  2. Heavy metal contamination of soil and sediment in Zambia | Ikenaka ...

    African Journals Online (AJOL)

    African Journal of Environmental Science and Technology. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 11 (2010) >. Log in or Register to get access to full text downloads.

  3. Optimal selection of biochars for remediating metals contaminated mine soils

    Science.gov (United States)

    Approximately 500,000 abandoned mines across the U.S. pose a considerable, pervasive risk to human health and the environment due to possible exposure to the residuals of heavy metal extraction. Historically, a variety of chemical and biological methods have been used to reduce ...

  4. Directed Selection of Biochars for Amending Metal Contaminated Mine Soils

    Science.gov (United States)

    Approximately 500,000 abandoned mines across the U.S. pose a considerable, pervasive risk to human health and the environment. World-wide the problem is even larger. Lime, organic matter, biosolids and other amendments have been used to decrease metal bioavailability in contami...

  5. Water and nutrient productivity in melon crop by fertigation under subsurface drip irrigation and mulching in contrasting soils

    Directory of Open Access Journals (Sweden)

    Rodrigo Otávio Câmara Monteiro

    2014-01-01

    Full Text Available Cropping intensification and technical, economic and environmental issues require efficient application of production factors to maintain the soil productive capacity and produce good quality fruits and vegetables. The production factors, water and NPK nutrients, are the most frequent limiting factors to higher melon yields. The objective of the present study was to identify the influence of subsurface drip irrigation and mulching in a protected environment on the water and NPK nutrients productivity in melon cropped in two soil types: sandy loam and clay. The melon crop cultivated under environmental conditions with underground drip irrigation at 0.20m depth, with mulching on sandy loam soil increased water and N, P2O5 and K use efficiency.

  6. On the control of irrigation through soil moisture measurement using a neutron depth probe in horizontal subsurface measuring circuits

    International Nuclear Information System (INIS)

    Schaecke, B.; Schaecke, E.

    1977-01-01

    An outline is given of the advantages inherent in soil moisture measurement by means of a neutron probe in horizontal subsurface measuring circuits for irrigation control. Preliminary experience for the setting up of a field calibration curve and for practical measurement are submitted. This technique includes the following advantages: almost complete covering of the upper soil range which is of interest to irrigation control; good measuring density; suitable distribution of measuring points per unit area; possibility of continuous probe passage; optimal repeatability of measurements; exploration of a unit area with but few measuring circuits; no obstacles to tillage, drilling, intercultivation and harvest operations; and complete conservation of crop and plot which is not reached with any other soil moisture measurement technique so far available. Making use of the above advantages, the new technique allows automatic irrigation control with only one neutron depth probe. (author)

  7. Algal-bacterial interactions in metal contaminated floodplain sediments

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Identification and Simulation of Subsurface Soil patterns using hidden Markov random fields and remote sensing and geophysical EMI data sets

    Science.gov (United States)

    Wang, Hui; Wellmann, Florian; Verweij, Elizabeth; von Hebel, Christian; van der Kruk, Jan

    2017-04-01

    Lateral and vertical spatial heterogeneity of subsurface properties such as soil texture and structure influences the available water and resource supply for crop growth. High-resolution mapping of subsurface structures using non-invasive geo-referenced geophysical measurements, like electromagnetic induction (EMI), enables a characterization of 3D soil structures, which have shown correlations to remote sensing information of the crop states. The benefit of EMI is that it can return 3D subsurface information, however the spatial dimensions are limited due to the labor intensive measurement procedure. Although active and passive sensors mounted on air- or space-borne platforms return 2D images, they have much larger spatial dimensions. Combining both approaches provides us with a potential pathway to extend the detailed 3D geophysical information to a larger area by using remote sensing information. In this study, we aim at extracting and providing insights into the spatial and statistical correlation of the geophysical and remote sensing observations of the soil/vegetation continuum system. To this end, two key points need to be addressed: 1) how to detect and recognize the geometric patterns (i.e., spatial heterogeneity) from multiple data sets, and 2) how to quantitatively describe the statistical correlation between remote sensing information and geophysical measurements. In the current study, the spatial domain is restricted to shallow depths up to 3 meters, and the geostatistical database contains normalized difference vegetation index (NDVI) derived from RapidEye satellite images and apparent electrical conductivities (ECa) measured from multi-receiver EMI sensors for nine depths of exploration ranging from 0-2.7 m. The integrated data sets are mapped into both the physical space (i.e. the spatial domain) and feature space (i.e. a two-dimensional space framed by the NDVI and the ECa data). Hidden Markov Random Fields (HMRF) are employed to model the

  11. Risk Assessment of Heavy Metal Contamination on Vegetables Grown in Long-term Wastewater Irrigated Urban Farming Sites in Accra, Ghana

    DEFF Research Database (Denmark)

    Lente, I.; Keraita, Bernard; Drechsel, P.

    2012-01-01

    Assessment was done of heavy-metal contamination and its related health risks in urban vegetable farming in Accra. Samples of irrigation water (n = 120), soil (n = 144) and five different kinds of vegetable (n = 240) were collected and analyzed for copper, zinc, lead, cadmium, chromium, nickel an...

  12. Application of an in-situ soil sampler for assessing subsurface biogeochemical dynamics in a diesel-contaminated coastal site during soil flushing operations.

    Science.gov (United States)

    Kwon, Man Jae; O'Loughlin, Edward J; Ham, Baknoon; Hwang, Yunho; Shim, Moojoon; Lee, Soonjae

    2018-01-15

    Subsurface biogeochemistry and contaminant dynamics during the remediation of diesel-contamination by in-situ soil flushing were investigated at a site located in a coastal region. An in-situ sampler containing diesel-contaminated soils separated into two size fractions (fraction were much higher than those in the fraction. Increases in soil TPH in DH1 were consistent with the expected outcomes following well pumping and surfactant injection used to enhance TPH extraction. However, the number of diesel-degrading microorganisms decreased after surfactant injection. 16S-rRNA gene-based analysis also showed that the community composition and diversity depended on both particle size and diesel contamination. The multidisciplinary approach to the contaminated site assessments showed that soil flushing with surfactant enhanced diesel extraction, but negatively impacted in-situ diesel biodegradation as well as groundwater quality. The results also suggest that the in-situ sampler can be an effective monitoring tool for subsurface biogeochemistry as well as contaminant dynamics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. HYDRUS simulations of the effects of dual-drip subsurface irrigation and a physical barrier on water movement and solute transport in soils

    OpenAIRE

    El-Nesr, MN; Alazba, AA; Šimůnek, J

    2014-01-01

    Subsurface drip irrigation systems, compared to other irrigation systems, enhance the delivery of water and nutrients directly into the root zone. However, in light-textured soils, certain quantities of water may percolate below the root zone due to the subsurface position of drip lines and/or poor management of irrigation systems. The main objective of this paper is to evaluate three technologies to enhance a spatial distribution of water and solutes in the root zone and to limit downward le...

  14. Sorption, desorption and mineralisation of the herbicides glyphosate and MCPA in samples from two Danish soil and subsurface profiles

    International Nuclear Information System (INIS)

    Sorensen, Sebastian R.; Schultz, Anne; Jacobsen, Ole S.; Aamand, Jens

    2006-01-01

    The vertical distribution of the sorption, desorption and mineralisation of glyphosate and MCPA was examined in samples from two contrasting soil and subsurface profiles, obtained from a sandy agricultural site and a non-agricultural clay rich site. The highest mineralisation of [ 14 C-methylen]glyphosate, with 9.3-14.7% degraded to 14 CO 2 within 3 months was found in the deepest sample from the clay site. In the deeper parts of the sandy profile high sorption and low desorption of glyphosate coincided with no or minor mineralisation indicating a limited glyphosate bioavailability. MCPA was readily mineralised except in the deepest samples from both sites. The highest MCPA mineralisation was detected just below the surface layers with 72% or 44% degraded to 14 CO 2 at the sandy or the clay sites, respectively. MCPA sorped to a minor extent in all samples and no indications of sorption-controlled mineralisation was revealed. None of the herbicides were mineralised under anoxic conditions. - Natural attenuation potential of the herbicides glyphosate and MCPA was assessed in soil and subsurface profiles

  15. Sorption, desorption and mineralisation of the herbicides glyphosate and MCPA in samples from two Danish soil and subsurface profiles

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Sebastian R. [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)]. E-mail: srs@geus.dk; Schultz, Anne [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Jacobsen, Ole S. [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Aamand, Jens [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

    2006-05-15

    The vertical distribution of the sorption, desorption and mineralisation of glyphosate and MCPA was examined in samples from two contrasting soil and subsurface profiles, obtained from a sandy agricultural site and a non-agricultural clay rich site. The highest mineralisation of [{sup 14}C-methylen]glyphosate, with 9.3-14.7% degraded to {sup 14}CO{sub 2} within 3 months was found in the deepest sample from the clay site. In the deeper parts of the sandy profile high sorption and low desorption of glyphosate coincided with no or minor mineralisation indicating a limited glyphosate bioavailability. MCPA was readily mineralised except in the deepest samples from both sites. The highest MCPA mineralisation was detected just below the surface layers with 72% or 44% degraded to {sup 14}CO{sub 2} at the sandy or the clay sites, respectively. MCPA sorped to a minor extent in all samples and no indications of sorption-controlled mineralisation was revealed. None of the herbicides were mineralised under anoxic conditions. - Natural attenuation potential of the herbicides glyphosate and MCPA was assessed in soil and subsurface profiles.

  16. Soil Physical Constraints on Intrinsic Biodegradation of Petroleum Vapors in a Layered Subsurface

    DEFF Research Database (Denmark)

    Kristensen, Andreas Houlberg; Henriksen, Kaj; Mortensen, Lars

    2010-01-01

    Intrinsic biodegradation of organic contaminants in the soil vadose zone depends on site-specific soil properties controlling biophysical and geochemical interactions within the soil pore space. In this study we evaluated the effect of soil texture and moisture conditions on aerobic biodegradatio...... in the deep vadose zone. As a result, management of petroleum hydrocarbon spill sites will benefit from site-specific conceptual models in which the vadose zone is divided into geological compartments with different biophysical potential for biodegradation and bioremediation....

  17. The influence of surface and incorporated lime and gypsiferous by-products on surface and subsurface soil acidity. II. Root growth and agronomic implications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.L.; Hedley, M.J.; Bolan, N.S.; Horne, D.J. [New Zealand Forest Research Institute, Rotorua (New Zealand)

    1999-04-01

    Lucerne (Medicago sativa. L) root elongation in acid soils amended by gypsiferous coal combustion by-products was investigated in a glasshouse study. Lime, fluidised bed boiler ash (FBA), and flue gas desulfurisation gypsum (FGDG) were mixed into the surface 50 mm of either an Allophanic (the Patua sand loam) or an Ultic (the Kaawa clay loam) soil column, at rates containing calcium equivalent to 5000 kg/ha of CaCO{sub 3}. Lucerne was grown on each column after it was leached with 400 mm of water. Whereas the lime treatment had no effect on root elongation in the acidic subsurface of the Patua soil, the FBA and FGDG treatments significantly improved lucerne root penetration into the subsurface soil. This was due to the `self liming effect` induced by sulfate adsorption. In contrast, topsoil incorporated amendments did not influence root penetration into the acidic subsurface of the Kaawa soil, which is dominated by permanently charged clay minerals. The `self-liming erect` caused by gypsum application is not a sustainable practice. Lime should be applied to neutralise the topsoil acidity, when gypsum is used as subsurface soil acidity ameliorant. FBA, which contains both lime and gypsum, can meet these requirements.

  18. Coupled Land Surface-Subsurface Hydrogeophysical Inverse Modeling to Estimate Soil Organic Carbon Content in an Arctic Tundra

    Science.gov (United States)

    Tran, A. P.; Dafflon, B.; Hubbard, S.

    2017-12-01

    Soil organic carbon (SOC) is crucial for predicting carbon climate feedbacks in the vulnerable organic-rich Arctic region. However, it is challenging to achieve this property due to the general limitations of conventional core sampling and analysis methods. In this study, we develop an inversion scheme that uses single or multiple datasets, including soil liquid water content, temperature and ERT data, to estimate the vertical profile of SOC content. Our approach relies on the fact that SOC content strongly influences soil hydrological-thermal parameters, and therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. The scheme includes several advantages. First, this is the first time SOC content is estimated by using a coupled hydrogeophysical inversion. Second, by using the Community Land Model, we can account for the land surface dynamics (evapotranspiration, snow accumulation and melting) and ice/liquid phase transition. Third, we combine a deterministic and an adaptive Markov chain Monte Carlo optimization algorithm to better estimate the posterior distributions of desired model parameters. Finally, the simulated subsurface variables are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using synthetic experiments. The results show that compared to inversion of single dataset, joint inversion of these datasets significantly reduces parameter uncertainty. The joint inversion approach is able to estimate SOC content within the shallow active layer with high reliability. Next, we apply the scheme to estimate OC content along an intensive ERT transect in Barrow, Alaska using multiple datasets acquired in the 2013-2015 period. The preliminary results show a good agreement between modeled and measured soil temperature, thaw layer thickness and electrical resistivity. The accuracy of estimated SOC content

  19. Impact of post-infiltration soil aeration at different growth stages of sub-surface trickle-irrigated tomato plants

    Science.gov (United States)

    Li, Yuan; Jia, Zong-xia; Niu, Wen-Quan; Wang, Jing-wei

    2016-07-01

    Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

  20. Evaluating Insects as Bioindicators of Heavy Metal Contamination and Accumulation near Industrial Area of Gujrat, Pakistan.

    Science.gov (United States)

    Azam, Iqra; Afsheen, Sumera; Zia, Ahmed; Javed, Muqaddas; Saeed, Rashid; Sarwar, Muhammad Kaleem; Munir, Bushra

    2015-01-01

    To study the accumulation and contamination of heavy metals (i.e., Cd, Cr, Cu, Ni, and Zn) in soil, air, and water, few insect species were assayed as ecological indicators. Study area comes under industrial zone of district Gujrat of Punjab, Pakistan. Insects used as bioindicators included a libellulid dragonfly (Crocothemis servilia), an acridid grasshopper (Oxya hyla hyla), and a nymphalid butterfly (Danaus chrysippus) near industrial zone of Gujrat. Accumulation of Cd was highest in insect species followed by Cu, Cr, Zn, and Ni at p Lepidoptera. The total metal concentrations in insects were pointed significantly higher at sites S3 (Mid of HalsiNala), S9 (End of HalsiNala), and S1 (Start of HalsiNala), whereas lowest value was detected at site S6 (Kalra Khasa) located far from industrial area. HACA indicates that these insect groups are potential indicators of metal contamination and can be used in biomonitoring.

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

    Science.gov (United States)

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

    2016-06-01

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

  2. Effects of golf course management on subsurface soil properties in Iowa

    Science.gov (United States)

    Streeter, Matthew T.; Schilling, Keith E.

    2018-05-01

    Currently, in the USA and especially in the Midwest region, urban expansion is developing turfgrass landscapes surrounding commercial sites, homes, and recreational areas on soils that have been agriculturally managed for decades. Often, golf courses are at the forefront of conversations concerning anthropogenic environmental impacts as they account for some of the most intensively managed soils in the world. Iowa golf courses provide an ideal location to evaluate whether golf course management is affecting the quality of soils at depth. Our study evaluated how soil properties relating to soil health and resiliency varied with depth at golf courses across Iowa and interpreted relationships of these properties to current golf course management, previous land use, and inherent soil properties. Systematic variation in soil properties including sand content, NO3, and soil organic matter (SOM) were observed with depth at six Iowa golf courses among three landform regions. Variability in sand content was identified between the 20 and 50 cm depth classes at all courses, where sand content decreased by as much as 37 %. Highest concentrations of SOM and NO3 were found in the shallowest soils, whereas total C and P variability was not related to golf course management. Sand content and NO3 were found to be directly related to golf course management, particularly at shallow depths. The effects of golf course management dissipated with depth and deeper soil variations were primarily due to natural geologic conditions. The two abovementioned soil properties were very noticeably altered by golf course management and may directly impact crop productivity, soil health, and water quality, and while NO3 may be altered relatively quickly in soil through natural processes, particle size of the soil may not be altered without extensive mitigation. Iowa golf courses continue to be developed in areas of land use change from historically native prairies and more recently agriculture to

  3. Yields and Nutritional of Greenhouse Tomato in Response to Different Soil Aeration Volume at two depths of Subsurface drip irrigation

    Science.gov (United States)

    Li, Yuan; Niu, Wenquan; Dyck, Miles; Wang, Jingwei; Zou, Xiaoyang

    2016-01-01

    This study investigated the effects of 4 aeration levels (varied by injection of air to the soil through subsurface irrigation lines) at two subsurface irrigation line depths (15 and 40 cm) on plant growth, yield and nutritional quality of greenhouse tomato. In all experiments, fruit number, width and length, yield, vitamin C, lycopene and sugar/acid ratio of tomato markedly increased in response to the aeration treatments. Vitamin C, lycopene, and sugar/acid ratio increased by 41%, 2%, and 43%, respectively, in the 1.5 times standard aeration volume compared with the no-aeration treatment. An interaction between aeration level and depth of irrigation line was also observed with yield, fruit number, fruit length, vitamin C and sugar/acid ratio of greenhouse tomato increasing at each aeration level when irrigation lines were placed at 40 cm depth. However, when the irrigation lines were 15 cm deep, the trend of total fruit yields, fruit width, fruit length and sugar/acid ratio first increased and then decreased with increasing aeration level. Total soluble solids and titrable acid decreased with increasing aeration level both at 15 and 40 cm irrigation line placement. When all of the quality factors, yields and economic benefit are considered together, the combination of 40 cm line depth and “standard” aeration level was the optimum combination. PMID:27995970

  4. Role of subsurface physics in the assimilation of surface soil moisture observations

    Science.gov (United States)

    Soil moisture controls the exchange of water and energy between the land surface and the atmosphere and exhibits memory that may be useful for climate prediction at monthly time scales. Though spatially distributed observations of soil moisture are increasingly becoming available from remotely sense...

  5. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen Grothe; Jensen, Karsten Høgh; Fredericia, Johnny

    1998-01-01

    of macropore structure and hydraulic efficiency, using image analysis and tension infiltration, and of soil water content, level of groundwater table, and chloride content of soil water within the soil profile yielded insights into small-scale processes and their associated variability. Macropore how...... into the soil profile. Dye infiltration experiments in the field as well as in the laboratory supported the recognition of the dominant contribution of macropores to the infiltration and transport process. The soil matrix significantly influenced the tracer distribution by acting as a source or sink...... for continuous solute exchange with the macropores. An average field-determined active macroporosity constituted 0.2% of the total porosity, or approximately 10% of the total macroporosity. (C) 1998 Elsevier Science B.V. All rights reserved....

  6. Characteristics and evaluation on heavy metal contamination in Changchun municipal waste landfill after closure.

    Science.gov (United States)

    Zhou, Xu-dan; Zhao, Chun-li; Qu, Tong-bao; Wang, Ying; Guo, Tai-jun; Sun, Xiao-gang

    2015-07-01

    In the present study, comprehensive investigation on the spot and typical investigation method were used to assess Mn, Zn, Pb, Cd, Cr, Ni, As and Cu level, pH value, organic matter, total nitrogen and total phosphorus contents in soil of Changchun municipal waste landfill. The results showed that soil in the closure area of Changchun municipal waste landfill was alkaline in nature and the average value of organic matter, total nitrogen and total phosphorus contents were lower than that in normal black soil in Changchun City of Jilin Province. Single factor indices of As, Pb and Cr content was > 1, where P(As) was 1.131, P(Pb) 1.061 and P(Cr) 1.092 mildly contaminated. In different sample spots but the same landfill time, the comprehensive Nemerow contamination indexes of 7a (5 #) and 7a (2 #) were P(2 comprehensive) = 1.176 and P(5 comprehensive) = 1.229. The performance value of of heavy metal contamination in soil was similar and there was a low ecological risk.

  7. Subsurface watering resulted in reduced soil N2O and CO2 emissions and their global warming potentials than surface watering

    Science.gov (United States)

    Wei, Qi; Xu, Junzeng; Yang, Shihong; Liao, Linxian; Jin, Guangqiu; Li, Yawei; Hameed, Fazli

    2018-01-01

    Water management is an important practice with significant effect on greenhouse gases (GHG) emission from soils. Nitrous oxide (N2O) and carbon dioxide (CO2) emissions and their global warming potentials (GWPs) from subsurface watering soil (SUW) were investigated, with surface watering (SW) as a control. Results indicated that the N2O and CO2 emissions from SUW soils were somewhat different to those from SW soil, with the peak N2O and CO2 fluxes from SUW soil reduced by 28.9% and 19.4%, and appeared 72 h and 168 h later compared with SW. The fluxes of N2O and CO2 from SUW soils were lower than those from SW soil in both pulse and post-pulse periods, and the reduction was significantly (p0.1) lower that from SW soil. Moreover, N2O and CO2 fluxes from both watering treatments increased exponentially with increase of soil water-filled pore space (WFPS) and temperature. Our results suggest that watering soil from subsurface could significantly reduce the integrative greenhouse effect caused by N2O and CO2 and is a promising strategy for soil greenhouse gases (GHGs) mitigation. And the pulse period, contributed most to the reduction in emissions of N2O and CO2 from soils between SW and SUW, should be a key period for mitigating GHGs emissions. Response of N2O and CO2 emissions to soil WFPS and temperature illustrated that moisture was the dominant parameters that triggering GHG pulse emissions (especially for N2O), and temperature had a greater effect on the soil microorganism activity than moisture in drier soil. Avoiding moisture and temperature are appropriate for GHG emission at the same time is essential for GHGs mitigation, because peak N2O and CO2 emission were observed only when moisture and temperature are both appropriate.

  8. Cold war legacy: sub-surface investigation of unsaturated prairie soil radiologically contaminated in 1951

    International Nuclear Information System (INIS)

    Sims, D.J.; Andrews, W.S.; Wang, Z.; Creber, K.A.M.

    2003-01-01

    An unintentional release of fission products (FPs) from a buried storage tank in 1951 resulted in 6.7 L of liquid, bearing radioactive material, being spilled into unsaturated prairie soil at a depth of 3.7 m. Since then, the site has been undisturbed. In October 2001, boreholes were drilled and soil samples were recovered for analysis. Gamma well logging showed higher than background radiation readings at a depth of 3.5 m (corresponding to the storage container location) and a peak reading at 4.7 m (attributed to the breakthrough curve). The soil was determined to be predominantly lean clay with a silty sand layer between 4.4 and 5.1 m. Future work includes radiochemical analysis, soil column simulation, determination of distribution coefficients and transport modelling. (author)

  9. Integration of pneumatic fracturing and in situ vitrification in the soil subsurface

    International Nuclear Information System (INIS)

    Luey, J.; Seiler, D.K.; Schuring, J.R.

    1995-02-01

    Pacific Northwest Laboratory is evaluating ways to increase the applicability of the in situ vitrification (ISV) process at hazardous and radioactive waste sites. One innovation is the placement of a conductive material that will facilitate initiating the ISV process at a target depth. A series of laboratory tests performed at the New Jersey Institute of Technology (NJIT) assessed the feasibility of pneumatic fracturing (PF) in the highly permeable soils of the Hanford Site. The NJIT tests included an analysis of Hanford soils, a series of PF injection tests, and a parametric analysis to determine how soil properties affect the PF process. Results suggest that the PF process can be applied to Hanford soils and that dry medium (e.g., conductive material such as graphite flake) can be injected into the fracture. This paper describes the laboratory testing performed at NJIT, its results, and the application of those results to plans for a field demonstration at Hanford

  10. Towards the Wetness Characterization of Soil Subsurface Using Fibre Optic Distributed Acoustic Sensing

    Science.gov (United States)

    Ciocca, F.; Bodet, L.; Simon, N.; Karaulanov, R.; Clarke, A.; Abesser, C.; Krause, S.; Chalari, A.; Mondanos, M.

    2017-12-01

    Active seismic methods combined with detectors deployed at the soil surface, such as vertical collinear geophones, have revealed great potential for hydrogeophysical characterization of the soil vadose zone. In particular, recent findings have highlighted a clear dependence of both P-waves arrival times and surface-wave dispersion on the local degree of soil saturation, visible at laboratory as well as at field scale. In this study, we investigate the sensitivity of a fibre optic Distributed Acoustic Sensor (DAS) to different soil saturation. In vertical seismic applications, DAS have proven to offer equal and often better performance compared to the geophones, with the advantage that a fibre optic cable, whose length can reach 40 km, replaces the array of geophones as sensing element. We present the response to active seismic tests of 20 m of fibre optic cable buried in a poorly permeable bare soil. Tests were conducted in different moments of the year, with saturation monitored by means of independent dielectric probes. Body-wave travel times as well as surface-wave dispersion are compared. Finally, we discuss the possibility to determine a site-specific relation between the Poisson ratio and the soil saturation. This research has been performed in the framework of the British National Environmental Research Council (NERC) funded Distributed intelligent Heat Pulse System (DiHPS) project and of the Marie Curie H2020 Research and Innovation Staff Exchange (RISE) consortium Hi-Freq.

  11. Long-term bioremediation of a subsurface plume in silty soil

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.

    2000-01-01

    In northern Virginia, a loss from a tank farm has produced two plumes, containing about 200,000 gal of diesel fuel, jet-A fuel, and gasoline. Evidence suggests that the longest part of the contamination plume moved to its present length of 2,500 ft in less than 5 years. Since natural biodegradation would require about 2,500 years to reduce the hydrocarbon contamination to the remediation endpoints, other methods have been considered. Excavation of the plumes would take an estimated 5 years. However, the tank farm is surrounded by commercial buildings and expensive homes, and many of these buildings would have to be removed to reach the plumes. Enhanced natural bioremediation would require about 200 years at a start-up cost of about $1 million dollars and recurring costs of approximately $500,000/year. Infiltration galleries and enhanced subsurface permeability could reduce the remediation time to as little as 20 years

  12. Genesis of textural contrasts in subsurface soil horizons in the Northern Pantanal-Brazil

    Directory of Open Access Journals (Sweden)

    Alexandre Ferreira do Nascimento

    2013-10-01

    Full Text Available The Pantanal region can be characterized as a quaternary floodplain with predominant sedimentation in the form of alluvial fans. In the geomorphologic and sedimentary evolution, the avulsion process is inherent to this depositional system and its dynamics, together with surface water floods, influence soil sedimentation on this plain. The knowledge and differentiation of these two events can contribute to a better understanding of the variability of soil properties and distribution under the influence of these sedimentation processes. Therefore, this study investigated the genesis of soils in the Northern Pantanal with textural contrasts in deeper horizons and their relationship with the depositional system dynamics. We analyzed four soil profiles in the region of Barão de Melgaço, Mato Grosso State, Brazil (RPPN SESC Pantanal. Two profiles were sampled near the Rio Cuiabá (AP1 and AP4 and two near the Rio São Lourenço (AP10 and AP11. In AP11, the horizons contrast in particle size between the profile basis and the surface. In AP1, AP4 and AP10, the horizons overlaying the sand layer have similar particle size properties, mainly in terms of sand distribution. In the first case, floods (surface water seem to have originated the horizons and layers with contrasting texture. In the second case, avulsion is the most pronounced process. Therefore, the two modes can form soils with contrasting texture that are discriminable by soil morphology, based on the distinct features associated to the specific sedimentation processes.

  13. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    Energy Technology Data Exchange (ETDEWEB)

    Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

    2013-10-04

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  14. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    Science.gov (United States)

    Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

    2013-01-01

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  15. Modelling shallow landslide susceptibility by means of a subsurface flow path connectivity index and estimates of soil depth spatial distribution

    Directory of Open Access Journals (Sweden)

    C. Lanni

    2012-11-01

    Full Text Available Topographic index-based hydrological models have gained wide use to describe the hydrological control on the triggering of rainfall-induced shallow landslides at the catchment scale. A common assumption in these models is that a spatially continuous water table occurs simultaneously across the catchment. However, during a rainfall event isolated patches of subsurface saturation form above an impeding layer and their hydrological connectivity is a necessary condition for lateral flow initiation at a point on the hillslope.

    Here, a new hydrological model is presented, which allows us to account for the concept of hydrological connectivity while keeping the simplicity of the topographic index approach. A dynamic topographic index is used to describe the transient lateral flow that is established at a hillslope element when the rainfall amount exceeds a threshold value allowing for (a development of a perched water table above an impeding layer, and (b hydrological connectivity between the hillslope element and its own upslope contributing area. A spatially variable soil depth is the main control of hydrological connectivity in the model. The hydrological model is coupled with the infinite slope stability model and with a scaling model for the rainfall frequency–duration relationship to determine the return period of the critical rainfall needed to cause instability on three catchments located in the Italian Alps, where a survey of soil depth spatial distribution is available. The model is compared with a quasi-dynamic model in which the dynamic nature of the hydrological connectivity is neglected. The results show a better performance of the new model in predicting observed shallow landslides, implying that soil depth spatial variability and connectivity bear a significant control on shallow landsliding.

  16. In-situ remediation system for groundwater and soils

    Science.gov (United States)

    Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

    1993-01-01

    A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

  17. Metal Contamination of the Natural Environment in Norway from Long Range Atmospheric Transport

    International Nuclear Information System (INIS)

    Steinnes, E.

    2001-01-01

    Long range atmospheric transport is the most important source of contamination to the natural environment in Norway with many heavy metals. Investigations based on aerosol studies, bulk deposition measurements and moss analysis show that airborne transport from other parts of Europe is the major mode for supply of vanadium, zinc, arsenic, selenium, molybdenum, cadmium, tin,antimony, tellurium, thallium, lead, and bismuth, whereas metals such as chromium, nickel, and copper are mainly derived from point sources within Norway and in northwestern Russia close to the Norwegian border. Elements associated with long range transport show substantial enrichment in the humus horizon of natural soils in southern Norway, sometimes to levels suspected to cause effects on soil microbial processes. E.g. lead concentration values of 150-200 ppm are observed in the most contaminated areas in the south as compared to about 5 ppm in the far north. Elements such as lead and cadmium also show enrichment in some terrestrial food chains. These elements also show considerably elevated levels over background concentrations in the water and sediment of small lakes in the southern part of the country. Retrospective studies based on ombrogenous peatcores indicate that long range transport has been a significant source of heavy metal contamination in southern Norway for the last couple of centuries. The deposition of most heavy metals in Norway has been considerably reduced over the last 20 yr, with the exception of contributions in the north from Russian smelters

  18. Fingerprinting two metal contaminants in streams with Cu isotopes near the Dexing Mine, China

    Energy Technology Data Exchange (ETDEWEB)

    Song, Shiming [Chinese Geological Survey, Nanjing Center, Nanjing (China); Mathur, Ryan, E-mail: mathurr@juniata.edu [Department of Geology, Juniata College, Huntingdon, PA (United States); Ruiz, Joaquin [Department of Geosciences, University of Arizona, Tucson, AZ (United States); Chen, Dandan [Chinese Geological Survey, Nanjing Center, Nanjing (China); Allin, Nicholas [Department of Geology, Juniata College, Huntingdon, PA (United States); Guo, Kunyi; Kang, Wenkai [Chinese Geological Survey, Nanjing Center, Nanjing (China)

    2016-02-15

    Transition metal isotope signatures are becoming useful for fingerprinting sources in surface waters. This study explored the use of Cu isotope values to trace dissolved metal contaminants in stream water throughout a watershed affected by mining by-products of the Dexing Mine, the largest porphyry Cu operation in Asia. Cu isotope values of stream water were compared to potential mineral sources of Cu in the mining operation, and to proximity to the known Cu sources. The first mineral source, chalcopyrite, CuFeS{sub 2} has a ‘tight’ cluster of Cu isotope values (− 0.15‰ to + 1.65‰; + 0.37 ± 0.6‰, 1σ, n = 10), and the second mineral source, pyrite (FeS{sub 2}), has a much larger range of Cu isotope values (− 4‰ to + 11.9‰; 2.7 ± 4.3‰, 1σ, n = 16). Dissolved Cu isotope values of stream water indicated metal derived from either chalcopyrite or pyrite. Above known Cu mineralization, stream waters are approximately + 1.5‰ greater than the average chalcopyrite and are interpreted as derived from weathering of chalcopyrite. In contrast, dissolved Cu isotope values in stream water emanating from tailings piles had Cu isotope values similar to or greater than pyrite (>+6‰, a common mineral in the tailings). These values are interpreted as sourced from the tailings, even in solutions that possess significantly lower concentrations of Cu (< 0.05 ppm). Elevated Cu isotope values were also found in two soil and two tailings samples (δ{sup 65}Cu ranging between + 2 to + 5‰). These data point to the mineral pyrite in tailings as the mineral source for the elevated Cu isotope values. Therefore, Cu isotope values of waters emanating from a clearly contaminated drainage possess different Cu isotope values, permitting the discrimination of Cu derived from chalcopyrite and pyrite in solution. Data demonstrate the utility of Cu isotopic values in waters, minerals, and soils to fingerprint metallic contamination for environmental problems. - Highlights:

  19. Degradation of atrazine and isoproturon in surface and sub-surface soil materials undergoing different moisture and aeration conditions.

    Science.gov (United States)

    Issa, Salah; Wood, Martin

    2005-02-01

    The influence of different moisture and aeration conditions on the degradation of atrazine and isoproturon was investigated in environmental samples aseptically collected from surface and sub-surface zones of agricultural land. The materials were maintained at two moisture contents corresponding to just above field capacity or 90% of field capacity. Another two groups of samples were adjusted with water to above field capacity, and, at zero time, exposed to drying-rewetting cycles. Atrazine was more persistent (t(1/2) = 22-35 days) than isoproturon (t(1/2) = 5-17 days) in samples maintained at constant moisture conditions. The rate of degradation for both herbicides was higher in samples maintained at a moisture content of 90% of field capacity than in samples with higher moisture contents. The reduction in moisture content in samples undergoing desiccation from above field capacity to much lower than field capacity enhanced the degradation of isoproturon (t(1/2) = 9-12 days) but reduced the rate of atrazine degradation (t(1/2) = 23-35 days). This demonstrates the variability between different micro-organisms in their susceptibility to desiccation. Under anaerobic conditions generated in anaerobic jars, atrazine degraded much more rapidly than isoproturon in materials taken from three soil profiles (0-250 cm depth). It is suggested that some specific micro-organisms are able to survive and degrade herbicide under severe conditions of desiccation. Copyright (c) 2005 Society of Chemical Industry.

  20. Soil archives of a Fluvisol: subsurface analysis and soil history of the medieval city centre of Vlaardingen, the Netherlands - an integral approach

    Science.gov (United States)

    Kluiving, Sjoerd; de Ridder, Tim; van Dasselaar, Marcel; Roozen, Stan; Prins, Maarten

    2016-06-01

    The medieval city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Maas, the Merwede, and the Vlaarding. A church of the early 8th century AD was already located here. In a short period of time, Vlaardingen developed in the 11th century AD into an international trading place and into one of the most important places in the former county of Holland. Starting from the 11th century AD, the river Maas repeatedly threatened to flood the settlement. The flood dynamics were registered in Fluvisol archives and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of these vulnerable soil archives an extensive interdisciplinary research effort (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna) started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the settlement mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil description, micromorphological, and geochemical (XRF - X-ray fluorescence) analysis. The soil sequence of 5 m thickness exhibits a complex mix of "natural" as well as "anthropogenic" layering and initial soil formation that enables us to make a distinction between relatively stable periods and periods with active sedimentation. In this paper the results of this interdisciplinary project are demonstrated in a number of cross-sections with interrelated geological, pedological, and archaeological stratification. A distinction between natural and anthropogenic layering is made on the basis of the occurrence of the chemical elements phosphor and potassium. A series of four stratigraphic and sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, in

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    communities can help document causal relationships between metal contamination and biological effects. Total or total-recoverable metal concentrations in sediments are the most common measure of metal contamination in sediments, but metal concentrations in labile sediment fractions (e.g., determined as part of selective sediment extraction protocols) may better represent metal bioavailability. Metals released by the weak-acid extraction of acid-volatile sulfide (AVS), termed simultaneously-extracted metals (SEM), are widely used to estimate the ‘potentially-bioavailable’ fraction of metals that is not bound to sulfides (i.e., SEM-AVS). Metal concentrations in pore water are widely considered to be direct measures of metal bioavailability, and predictions of toxicity based on pore-water metal concentrations may be further improved by modeling interactions of metals with other pore-water constituents using Biotic Ligand Models. Data from sediment toxicity tests and metal analyses has provided the basis for development of sediment quality guidelines, which estimate thresholds for toxicity of metals in sediments. Empirical guidelines such as Probable Effects Concentrations or (PECs) are based on associations between sediment metal concentrations and occurrence of toxic effects in large datasets. PECs do not model bioavailable metals, but they can be used to estimate the toxicity of metal mixtures using by calculation of probable effect quotients (PEQ = sediment metal concentration/PEC). In contrast, mechanistic guidelines, such as Equilibrium Partitioning Sediment Benchmarks (ESBs) attempt to predict both bioavailability and mixture toxicity. Application of these simple bioavailability models requires more extensive chemical characterization of sediments or pore water, compared to empirical guidelines, but may provide more reliable estimates of metal toxicity across a wide range of sediment types

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2011-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Yang Guan

    2014-07-01

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

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

    Directory of Open Access Journals (Sweden)

    LUO Man

    2016-11-01

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

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

    Science.gov (United States)

    Guan, Yang; Shao, Chaofeng; Ju, Meiting

    2014-01-01

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

  7. Evaluating Insects as Bioindicators of Heavy Metal Contamination and Accumulation near Industrial Area of Gujrat, Pakistan

    Directory of Open Access Journals (Sweden)

    Iqra Azam

    2015-01-01

    Full Text Available To study the accumulation and contamination of heavy metals (i.e., Cd, Cr, Cu, Ni, and Zn in soil, air, and water, few insect species were assayed as ecological indicators. Study area comes under industrial zone of district Gujrat of Punjab, Pakistan. Insects used as bioindicators included a libellulid dragonfly (Crocothemis servilia, an acridid grasshopper (Oxya hyla hyla, and a nymphalid butterfly (Danaus chrysippus near industrial zone of Gujrat. Accumulation of Cd was highest in insect species followed by Cu, Cr, Zn, and Ni at p<0.05. Hierarchical cluster analysis (HACA was carried out to study metal accumulation level in all insects. Correlation and regression analysis confirmed HACA observations and declared concentration of heavy metals above permissible limits. Metal concentrations in insects were significantly higher near industries and nallahs in Gujrat and relatively higher concentrations of metals were found in Orthoptera than Odonata and Lepidoptera. The total metal concentrations in insects were pointed significantly higher at sites S3 (Mid of HalsiNala, S9 (End of HalsiNala, and S1 (Start of HalsiNala, whereas lowest value was detected at site S6 (Kalra Khasa located far from industrial area. HACA indicates that these insect groups are potential indicators of metal contamination and can be used in biomonitoring.

  8. Integrated risk analysis of a heavy-metal-contaminated site in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Ching-Tsan Tsai [China Medical College, Taichung (Taiwan, Province of China); Wang, J.H.C. [National Science Council, Taipei (Taiwan, Province of China)

    1996-12-31

    The Love Canal episode began the long battle on hazardous wastes in the United States. Obviously, the potential danger of hazardous wastes is one of the hottest issues among environmental professionals as well as the public. The problems of hazardous wastes in economically booming Taiwan are also alarming. Several farmlands in northern Taiwan were contaminated heavily by industrial effluents containing heavy metals (cadmium and lead) in the early 1980s. Regardless of the many studies that have been conducted about these polluted farmlands, there has not been any remediation - just a passive abandonment of farming activities with minimal compensation. This paper addresses a heavy-metal-contaminated fanning area. A pollution profile across time is delineated using information from the abundance of reports, and the contamination is modeled mathematically. The past, the present, and future exposures are also modeled. The results are presented in terms of societal impacts and health effects. Reasonable soil guidelines for cleanup are estimated, and recommendations for rational mitigation solutions are presented. The current strategies for cleanup actions are also described. 23 refs., 4 figs., 5 tabs.

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

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  10. A trench study to assess transfer of pesticides in subsurface lateral flow for a soil with contrasting texture on a sloping vineyard in Beaujolais.

    Science.gov (United States)

    Peyrard, X; Liger, L; Guillemain, C; Gouy, V

    2016-01-01

    Subsurface lateral flow in both texture-contrast soils and catchments with shallow bedrock is suspected to be a non-point source of contamination of watercourses by pesticides used in agriculture. As a case study, the north of the Beaujolais region (eastern France) provides a favorable environment for such contamination due to its agro-pedo-climatic conditions. Environments seen in the Beaujolais region include intense viticulture, permeable and shallow soils, steep hillslopes, and storms that occur during the periods of pesticide application. Watercourse contamination by pesticides has been widely observed in this region, and offsite pesticide transport by subsurface lateral flow is suspected to be involved in diffuse and chronic presence of pesticides in surface water. In order to confirm and quantify the potential role of such processes in pesticide transfer, an automated trench system has been designed. The trench was set up on a steep farmed hillslope in a texture-contrast soil. It was equipped with a tipping bucket flow meter and an automatic sampler to monitor pesticide concentrations in lateral flow at fine resolution, by means of a flow-dependent sampling strategy. Four pesticides currently used in vine growing were studied to provide a range of mobility properties: one insecticide (chlorpyrifos-methyl) and three fungicides (spiroxamine, tebuconazole, and dimethomorph). With this system, it was possible to study pesticide concentration dynamics in the subsurface lateral flow, generated by substantial rainfall events following pesticide applications. The experimental design ascertained to be a suitable method in which to monitor subsurface lateral flow and related transfer of pesticides.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  12. Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

    Science.gov (United States)

    Story, Sandra; Brigmon, Robin L

    2017-03-01

    Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications. Copyright © 2016. Published by Elsevier Inc.

  13. Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

    International Nuclear Information System (INIS)

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Lapen, David R.; Topp, Edward

    2015-01-01

    In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with 14 C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants

  14. Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rajab, Abdul Jabbar; Sabourin, Lyne [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, Western University, London, ON N6A 5B7 (Canada)

    2015-04-15

    In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with {sup 14}C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants.

  15. Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India.

    Science.gov (United States)

    Pradhan, Jatindra Kumar; Kumar, Sudhir

    2014-01-01

    Nowadays, e-waste is a major source of environmental problems and opportunities due to presence of hazardous elements and precious metals. This study was aimed to evaluate the pollution risk of heavy metal contamination by informal recycling of e-waste. Environmental risk assessment was determined using multivariate statistical analysis, index of geoaccumulation, enrichment factor, contamination factor, degree of contamination and pollution load index by analysing heavy metals in surface soils, plants and groundwater samples collected from and around informal recycling workshops in Mandoli industrial area, Delhi, India. Concentrations of heavy metals like As (17.08 mg/kg), Cd (1.29 mg/kg), Cu (115.50 mg/kg), Pb (2,645.31 mg/kg), Se (12.67 mg/kg) and Zn (776.84 mg/kg) were higher in surface soils of e-waste recycling areas compared to those in reference site. Level exceeded the values suggested by the US Environmental Protection Agency (EPA). High accumulations of heavy metals were also observed in the native plant samples (Cynodon dactylon) of e-waste recycling areas. The groundwater samples collected form recycling area had high heavy metal concentrations as compared to permissible limit of Indian Standards and maximum allowable limit of WHO guidelines for drinking water. Multivariate analysis and risk assessment studies based on total metal content explains the clear-cut differences among sampling sites and a strong evidence of heavy metal pollution because of informal recycling of e-waste. This study put forward that prolonged informal recycling of e-waste may accumulate high concentration of heavy metals in surface soils, plants and groundwater, which will be a matter of concern for both environmental and occupational hazards. This warrants an immediate need of remedial measures to reduce the heavy metal contamination of e-waste recycling sites.

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

    Science.gov (United States)

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

    2008-12-01

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

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

    Science.gov (United States)

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

    2006-12-01

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

  18. Mineralogical, chemical, organic and microbial properties of subsurface soil cores from Mars Desert Research Station (Utah, USA): Phyllosilicate and sulfate analogues to Mars mission landing sites

    Science.gov (United States)

    Stoker, Carol R.; Clarke, Jonathan; Direito, Susana O. L.; Blake, David; Martin, Kevin R.; Zavaleta, Jhony; Foing, Bernard

    2011-07-01

    We collected and analysed soil cores from four geologic units surrounding Mars Desert Research Station (MDRS) Utah, USA, including Mancos Shale, Dakota Sandstone, Morrison formation (Brushy Basin member) and Summerville formation. The area is an important geochemical and morphological analogue to terrains on Mars. Soils were analysed for mineralogy by a Terra X-ray diffractometer (XRD), a field version of the CheMin instrument on the Mars Science Laboratory (MSL) mission (2012 landing). Soluble ion chemistry, total organic content and identity and distribution of microbial populations were also determined. The Terra data reveal that Mancos and Morrison soils are rich in phyllosilicates similar to those observed on Mars from orbital measurements (montmorillonite, nontronite and illite). Evaporite minerals observed include gypsum, thenardite, polyhalite and calcite. Soil chemical analysis shows sulfate the dominant anion in all soils and SO4>>CO3, as on Mars. The cation pattern Na>Ca>Mg is seen in all soils except for the Summerville where Ca>Na. In all soils, SO4 correlates with Na, suggesting sodium sulfates are the dominant phase. Oxidizable organics are low in all soils and range from a high of 0.7% in the Mancos samples to undetectable at a detection limit of 0.1% in the Morrison soils. Minerals rich in chromium and vanadium were identified in Morrison soils that result from diagenetic replacement of organic compounds. Depositional environment, geologic history and mineralogy all affect the ability to preserve and detect organic compounds. Subsurface biosphere populations were revealed to contain organisms from all three domains (Archaea, Bacteria and Eukarya) with cell density between 3.0×106 and 1.8×107 cells ml-1 at the deepest depth. These measurements are analogous to data that could be obtained on future robotic or human Mars missions and results are relevant to the MSL mission that will investigate phyllosilicates on Mars.

  19. Metal Contamination In Plants Due To Tannery Effluent

    Directory of Open Access Journals (Sweden)

    Md. Farhad Ali

    2015-08-01

    Full Text Available Abstract This paper analyzes the determination of heavy metals named Chromium Lead and Cadmium deposited in soil as well as in the plants and vegetables due to the tanning industries of the area of Hazaribagh Dhaka. The tanneries discharge untreated tannery effluents which get mixed with the soil water of rivers and canals in this area. The determination of metals was performed for the soil that was collected from the land adjacent to the canals which bear untreated tannery effluents. The soil is affected with the untreated effluents through the deposition of heavy metals. The metals were furthers deposited into the plants and vegetables grown on that soil. The roots stems and leaves of the plants of Jute Corchorus capsularis and Spinach Basella alba grown on that soil were analyzed for determining these metals. Extreme amount of chromium was found for plants and again Lead Cadmium were found in higher amount in these parts of the two plants. These two plants are taken as a popular vegetables extensively. In case of soil the amount of Chromium Lead and Cadmium were analyzed as 87 mgL 0.131 mgL and 0.190 mgL respectively. For the roots stems and leaves of Jute Corchorus capsularis the average values are 115.62 mgL for Chromium 11.25 mgL for Lead and 2.27 mgL for Cadmium respectively. Again in case of Spinach Basella alba 124.42 mgL was found for Chromium 7.38 mgL for lead and 2.97 mgL for Cadmium as average values for these parts of the two trees. All the observed values of metals of Chromium Lead and Cadmium are higher than the permissible and specially for Chromium the amount is extremely higher.

  20. Soil archives of a Fluvisol, part II. Archaeostratigraphical model of the subsurface of the medieval city centre of Vlaardingen, the Netherlands

    Science.gov (United States)

    Kluiving, Sjoerd; De Ridder, Tim; van Dasselaar, Marcel; Prins, Maarten

    2017-04-01

    In Medieval times the city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Meuse, the Merwede and the Vlaarding. A church of early 8th century was already located here. In a short period of time Vlaardingen developed into an international trading place, the most important place in the former county of Holland. Starting from the 11th century the river Meuse threatened to flood the settlement. These floods have been registered in the archives of the fluvisol and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of this vulnerable soil archive an extensive interdisciplinary research (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna has started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil descriptive, micromorphological and geochemical (XRF) analysis. The soil sequence of 5 meters thickness exhibits a complex mix of 'natural' as well as 'anthropogenic layering' and initial soil formation that enables to make a distinction for relatively stable periods between periods with active sedimentation. In this paper the results of this large-scale project are demonstrated in a number of cross-sections with interrelated geological, pedological and archaeological stratification. Distinction between natural and anthropogenic layering is made on the occurrence of chemical elements phosphor and potassium. A series of four stratigraphic / sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, we know that the medieval landscape was drowned while it was inhabited in the 12th century AD. After a final

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

    Directory of Open Access Journals (Sweden)

    Leita L.

    2013-04-01

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

  2. Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India.

    Science.gov (United States)

    Khatun, Amina; Pal, Sandipan; Mukherjee, Aloke Kumar; Samanta, Palas; Mondal, Subinoy; Kole, Debraj; Chandra, Priyanka; Ghosh, Apurba Ratan

    2016-01-01

    The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus . The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg)>Cu (29.9±10.2 mg/kg)>Pb (22.7±10.3 mg/kg)>Cd (3.7±2.2 mg/kg). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations ( p <0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation ( p <0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p <0.05 level. Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta .

  3. Mucilaginibacter pedocola sp. nov., isolated from a heavy-metal-contaminated paddy field.

    Science.gov (United States)

    Tang, Jingwei; Huang, Jing; Qiao, Zixu; Wang, Rui; Wang, Gejiao

    2016-10-01

    Strain TBZ30T was isolated from soil of a heavy-metal-contaminated paddy field. Cells of strain TBZ30T were Gram-staining-negative, rod-shaped, non-motile and non-spore-forming. The isolate was strictly aerobic, pink-pigmented, catalase- and oxidase-positive and produced exopolysaccharides. On the basis of 16S rRNA gene phylogeny, strain TBZ30T belonged to the genus Mucilaginibacter and appeared most closely related to Mucilaginibacter gynuensis YC7003T (95.8 %), Mucilaginibacter litoreus BR-18T (95.4 %) and Mucilaginibacter mallensis MP1X4T (95.4 %). Strain TBZ30T contained menaquinone-7 as the only ubiquinone. The main cellular fatty acids included summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, C16 : 0, iso-C17 : 0 3-OH and C16 : 1ω5c. The polar lipids were phosphatidylethanolamine, an unidentified phospholipid, two unidentified aminophospholipids, four unidentified aminolipids, three unidentified lipids and two unidentified glycolipids. The genomic DNA G+C content was 49.0 mol%. On the basis of polyphasic taxonomy analyses, strain TBZ30T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter pedocola sp. nov. is proposed. The type strain is TBZ30T (=KCTC 42833T=CCTCC AB 2015301T).

  4. Heavy Metal Contamination and Health Risk Assessment in the Vicinity of a Tailing Pond in Guangdong, China

    Science.gov (United States)

    Liang, Yaya; Yi, Xiaoyun; Dang, Zhi; Wang, Qin; Luo, Houmei; Tang, Jie

    2017-01-01

    The purpose of this study was to assess heavy metal contamination and health risks for residents in the vicinity of a tailing pond in Guangdong, southern China. Water, soil, rice, and vegetable samples were collected from the area in the vicinity of the tailing pond. Results showed that surface water was just polluted by Ni and As, while groundwater was not contaminated by heavy metals. The concentrations of Pb, Zn, Cu, Cd, Ni, and As in the paddy soil exceeded the standard values but not those of Cr. In vegetable soils, the concentration of heavy metals was above the standard values except for Ni and As. Soil heavy metal concentrations generally decreased with increasing distance from the polluting source. Leafy vegetables were contaminated by Pb, Cr, Cd, and Ni, while the non-leafy vegetables were contaminated only by Cr. There was a significant difference in heavy metal concentrations between leafy vegetables and non-leafy vegetables. Almost all the rice was polluted by heavy metals. Diet was the most significant contributor to non-carcinogenic risk, which was significantly higher than the safe level of 1. The total cancer risk was also beyond the safe range (10−6–10−4). Results revealed that there is a risk of potential health problems to residents in the vicinity of the tailing pond. PMID:29231884

  5. Heavy Metal Contamination and Health Risk Assessment in the Vicinity of a Tailing Pond in Guangdong, China.

    Science.gov (United States)

    Liang, Yaya; Yi, Xiaoyun; Dang, Zhi; Wang, Qin; Luo, Houmei; Tang, Jie

    2017-12-12

    The purpose of this study was to assess heavy metal contamination and health risks for residents in the vicinity of a tailing pond in Guangdong, southern China. Water, soil, rice, and vegetable samples were collected from the area in the vicinity of the tailing pond. Results showed that surface water was just polluted by Ni and As, while groundwater was not contaminated by heavy metals. The concentrations of Pb, Zn, Cu, Cd, Ni, and As in the paddy soil exceeded the standard values but not those of Cr. In vegetable soils, the concentration of heavy metals was above the standard values except for Ni and As. Soil heavy metal concentrations generally decreased with increasing distance from the polluting source. Leafy vegetables were contaminated by Pb, Cr, Cd, and Ni, while the non-leafy vegetables were contaminated only by Cr. There was a significant difference in heavy metal concentrations between leafy vegetables and non-leafy vegetables. Almost all the rice was polluted by heavy metals. Diet was the most significant contributor to non-carcinogenic risk, which was significantly higher than the safe level of 1. The total cancer risk was also beyond the safe range (10 -6 -10 -4 ). Results revealed that there is a risk of potential health problems to residents in the vicinity of the tailing pond.

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

    International Nuclear Information System (INIS)

    Gawel, James E.; Hemond, Harold F.

    2004-01-01

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

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

    African Journals Online (AJOL)

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

  8. Heavy metal contamination of some vegetables from pesticides and ...

    African Journals Online (AJOL)

    Vegetable farming in developing countries is characterized by the indiscriminate application of pesticides and the resultant pollution of agricultural soil with heavy metals that form constituents of these pesticides. These heavy metals have long term toxicity to human and other biota in the ecosystem. This problem is ...

  9. Warming Effects on Enzyme Activities are Predominant in Sub-surface Soils of an Arctic Tundra Ecosystem over 6-Year Field Manipulation

    Science.gov (United States)

    Kang, H.; Seo, J.; Kim, M.; Jung, J. Y.; Lee, Y. K.

    2017-12-01

    Arctic tundra ecosystems are of great importance because they store a large amount of carbon as un-decomposed organic matter. Global climate change is expected to affect enzyme activities and heterotrophic respiration in Arctic soils, which may accelerate greenhouse gas (GHG) emission through positive biological feedbacks. Unlike laboratory-based incubation experiments, field measurements often show different warming effects on decomposition of organic carbon and releases of GHGs. In the present study, we conducted a field-based warming experiment in Cambridge Bay, Canada (69°07'48″N, 105°03'36″W) by employing passive chambers during growing seasons over 6 years. A suite of enzyme activities (ß-glucosidase, cellobiohydrolase, N-acetylglucosaminidase, leucine aminopeptidase and phenol oxidase), microbial community structure (NGS), microbial abundances (gene copy numbers of bacteria and fungi), and soil chemical properties have been monitored in two depths (0-5 cm and 5-10 cm) of tundra soils, which were exposed to four different treatments (`control', `warming-only', `water-addition only', and both `warming and water-addition'). Phenol oxidase activity increased substantially, and bacterial community structure and abundance changed in the early stage (after 1 year's warming manipulation), but these changes disappeared afterwards. Most hydrolases were enhanced in surface soils by `water-addition only' over the period. However, the long-term effects of warming appeared in sub-surface soils where both `warming only' and `warming and water addition' increased hydrolase activities. Overall results of this study indicate that the warming effects on enzyme activities in surface soils are only short-term (phenol oxidase) or masked by water-limitation (hydrolases). However, hydrolases activities in sub-surface soils are more strongly enhanced than surface soils by warming, probably due to the lack of water limitation. Meanwhile, negative correlations between hydrolase

  10. Summary of Inorganic Compositional Data for Groundwater, Soil-Water, and Surface-Water Samples at the Headgate Draw Subsurface Drip Irrigation Site

    Energy Technology Data Exchange (ETDEWEB)

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupanic, John W.

    2007-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  11. Coupled land surface-subsurface hydrogeophysical inverse modeling to estimate soil organic carbon content and explore associated hydrological and thermal dynamics in the Arctic tundra

    Science.gov (United States)

    Phuong Tran, Anh; Dafflon, Baptiste; Hubbard, Susan S.

    2017-09-01

    Quantitative characterization of soil organic carbon (OC) content is essential due to its significant impacts on surface-subsurface hydrological-thermal processes and microbial decomposition of OC, which both in turn are important for predicting carbon-climate feedbacks. While such quantification is particularly important in the vulnerable organic-rich Arctic region, it is challenging to achieve due to the general limitations of conventional core sampling and analysis methods, and to the extremely dynamic nature of hydrological-thermal processes associated with annual freeze-thaw events. In this study, we develop and test an inversion scheme that can flexibly use single or multiple datasets - including soil liquid water content, temperature and electrical resistivity tomography (ERT) data - to estimate the vertical distribution of OC content. Our approach relies on the fact that OC content strongly influences soil hydrological-thermal parameters and, therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. We employ the Community Land Model to simulate nonisothermal surface-subsurface hydrological dynamics from the bedrock to the top of canopy, with consideration of land surface processes (e.g., solar radiation balance, evapotranspiration, snow accumulation and melting) and ice-liquid water phase transitions. For inversion, we combine a deterministic and an adaptive Markov chain Monte Carlo (MCMC) optimization algorithm to estimate a posteriori distributions of desired model parameters. For hydrological-thermal-to-geophysical variable transformation, the simulated subsurface temperature, liquid water content and ice content are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using different numerical experiments and evaluate the influence of measurement errors and benefit of joint inversion on the

  12. Coupled land surface–subsurface hydrogeophysical inverse modeling to estimate soil organic carbon content and explore associated hydrological and thermal dynamics in the Arctic tundra

    Directory of Open Access Journals (Sweden)

    A. P. Tran

    2017-09-01

    Full Text Available Quantitative characterization of soil organic carbon (OC content is essential due to its significant impacts on surface–subsurface hydrological–thermal processes and microbial decomposition of OC, which both in turn are important for predicting carbon–climate feedbacks. While such quantification is particularly important in the vulnerable organic-rich Arctic region, it is challenging to achieve due to the general limitations of conventional core sampling and analysis methods, and to the extremely dynamic nature of hydrological–thermal processes associated with annual freeze–thaw events. In this study, we develop and test an inversion scheme that can flexibly use single or multiple datasets – including soil liquid water content, temperature and electrical resistivity tomography (ERT data – to estimate the vertical distribution of OC content. Our approach relies on the fact that OC content strongly influences soil hydrological–thermal parameters and, therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. We employ the Community Land Model to simulate nonisothermal surface–subsurface hydrological dynamics from the bedrock to the top of canopy, with consideration of land surface processes (e.g., solar radiation balance, evapotranspiration, snow accumulation and melting and ice–liquid water phase transitions. For inversion, we combine a deterministic and an adaptive Markov chain Monte Carlo (MCMC optimization algorithm to estimate a posteriori distributions of desired model parameters. For hydrological–thermal-to-geophysical variable transformation, the simulated subsurface temperature, liquid water content and ice content are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using different numerical experiments and evaluate the influence of measurement errors and

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

    Science.gov (United States)

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

    2016-08-08

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

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

    Directory of Open Access Journals (Sweden)

    Marianna Bandiera

    2016-04-01

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

  15. Precipitation and soil impacts on partitioning of subsurface moisture in Avena barbata: Observations from a greenhouse experiment

    Energy Technology Data Exchange (ETDEWEB)

    Salve, R.; Torn, M.S.

    2011-03-01

    The primary objective of this study was to assess the impact of two grassland soils and precipitation regimes on soil-moisture dynamics. We set up an experiment in a greenhouse, and monitored soil moisture dynamics in mesocosms planted with Avena barbata, an annual species found in California grasslands. By repeating the precipitation input at regular intervals, we were able to observe plant manipulation of soil moisture during well-defined periods during the growing season. We found that the amount of water partitioned to evapotranspiration, seepage, and soil storage varied among different growth stages. Further, both soil type and precipitation regimes had a significant impact on redistributing soil moisture. Whereas in the low-precipitation treatments most water was released to the atmosphere as evapotranspiration, major losses from the high-precipitation treatment occurred as gravity drainage. Observations from this study emphasize the importance of understanding intra-seasonal relationships between vegetation, soil, and water.

  16. Heavy metal contamination in the vicinity of an industrial area near Bucharest.

    Science.gov (United States)

    Velea, Teodor; Gherghe, Liliana; Predica, Vasile; Krebs, Rolf

    2009-08-01

    Heavy metals such as lead are well known to cause harmful health effects. Especially children are particularly susceptible to increased levels of lead in their blood. It is also a fact that lead concentration is increasing in the environment due to increased anthropogenic activity. The risk of heavy metal contamination is pronounced in the environment adjacent to large industrial complexes. In a combined case study, the environmental pollution by heavy metals was related to children's health in the vicinity of an industrial area located 4 km south-east from Bucharest about 2 km east from the nearest town-Pantelimon. This site includes companies processing different, nonferrous solid wastes for recovery of heavy metals and producing different nonferrous alloys and lead batteries. In this paper, mainly the results of environmental sampling and analyses are summarized. Water, soil, and atmospheric deposition samples were collected from different locations within 3 km from the industrial area. For comparison, samples were also taken from Bucharest. Water samples were filtered (open collecting pots were used on nine different sites between August and November 2006. At most sampling locations, the heavy metal concentrations in soil decrease with increasing distance to the presumably major source of pollution. Highest heavy metal concentrations were found in 10-20 cm soil depths. There were also decreasing heavy metal concentrations for atmospheric deposition with increasing distance to the industrial site. In surface and groundwater samples, traces of zinc, copper and lead were detected. The heavy metal concentrations in soil were increased in the study area, mostly under legal action limits in low-concern areas (e.g., 1,000 mg Pb/kg dry soil), but often above action limits for high-concern areas (100 mg Pb/kg dry soil) such as populated areas. The soluble lead concentrations in water samples indicate a need for monitoring and assessing water quality in more detail. The

  17. Assessment of heavy metal contamination of dust at some selected fuel filling stations in Accra

    International Nuclear Information System (INIS)

    Afrifa, C. G.

    2011-07-01

    Heavy metal contaminated dust particles of fuel filling stations can be re-suspended into the ambient air and serve as a source of atmospheric pollution since the fine particles are aerodynamic and have longer life time in ambient air. This can cause ill-health effect on the fuel attendants and residents within the neighbourhood especially infants and the aged who are more vulnerable. In spite of this, not much research has been done on heavy metal contamination of dust at fuel filling stations. In this study, 55 dust samples were collected from six fuel filling stations in the Ga-East district and Accra Metropolitan assembly, both in Accra, in order to assess the levels of contamination of heavy metals; their possible sources and the human health risk associated with them. The dust samples were divided into two parts with one part sieved into four fractions using metric mesh sizes 500 µm, 200µm, 100µm and 45 µm, and pulverised. Total concentrations of heavy metals (Si, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Br, Rb, Sr, Y, Zr and Pb) were determined in the dust samples using energy dispersive X-ray fluorescence analysis. The pollution indices; enrichment factors (EF), index of geoaccumulation (Igeo), contamination factor (CF) and pollution load index (PLI) were used to identify possible levels of pollution from anthropogenic sources. The possible sources of metals were also identified with principal component analysis. Noncancer effect of children and adults due to exposure to dust from these fuel filling stations were also estimated. For the three fuelling areas, the average concentrations of V, Cr, Ni and Cu exceeded the acceptable values in common soil in the <45 µm fraction. The average concentration of Zn however exceeded the acceptable value only at the mixed-fuel fuelling area whereas the average concentration of Pb was within the acceptable value for all three fuelling areas. The dust samples showed moderate to significant enrichments for V, Cu, Br

  18. Utilization of subsurface microbial electrochemical systems to elucidate the mechanisms of competition between methanogenesis and microbial iron(III)/humic acid reduction in Arctic peat soils

    Science.gov (United States)

    Friedman, E. S.; Miller, K.; Lipson, D.; Angenent, L. T.

    2012-12-01

    High-latitude peat soils are a major carbon reservoir, and there is growing concern that previously dormant carbon from this reservoir could be released to the atmosphere as a result of continued climate change. Microbial processes, such as methanogenesis and carbon dioxide production via iron(III) or humic acid reduction, are at the heart of the carbon cycle in Arctic peat soils [1]. A deeper understanding of the factors governing microbial dominance in these soils is crucial for predicting the effects of continued climate change. In previous years, we have demonstrated the viability of a potentiostatically-controlled subsurface microbial electrochemical system-based biosensor that measures microbial respiration via exocellular electron transfer [2]. This system utilizes a graphite working electrode poised at 0.1 V NHE to mimic ferric iron and humic acid compounds. Microbes that would normally utilize these compounds as electron acceptors donate electrons to the electrode instead. The resulting current is a measure of microbial respiration with the electrode and is recorded with respect to time. Here, we examine the mechanistic relationship between methanogenesis and iron(III)- or humic acid-reduction by using these same microbial-three electrode systems to provide an inexhaustible source of alternate electron acceptor to microbes in these soils. Chamber-based carbon dioxide and methane fluxes were measured from soil collars with and without microbial three-electrode systems over a period of four weeks. In addition, in some collars we simulated increased fermentation by applying acetate treatments to understand possible effects of continued climate change on microbial processes in these carbon-rich soils. The results from this work aim to increase our fundamental understanding of competition between electron acceptors, and will provide valuable data for climate modeling scenarios. 1. Lipson, D.A., et al., Reduction of iron (III) and humic substances plays a major

  19. Assessment of Water Quality Index and Heavy Metal Contamination in Active and Abandoned Iron Ore Mining Sites in Pahang, Malaysia

    Directory of Open Access Journals (Sweden)

    Madzin Zafira

    2017-01-01

    Full Text Available The composition of heavy metals in water and surface soils of iron ore mining sites were investigated to evaluate on the potential occurrence of heavy metal contamination. Physico-chemical characteristics of the waters were also investigated to determine the current status of water quality index (WQI of the sites. Samples of water and surface soils of active mine (Kuala Lipis and abandoned mine (Bukit Ibam in Pahang were collected at four locations, respectively. The physico-chemical parameters measured for WQI were pH, dissolved oxygen, biological oxygen demand (BOD, chemical oxygen demand (COD, suspended solids (SS, and ammoniacal nitrogen (AN. The water quality parameters were classified according to the Department of Environment (DOE water quality classification. The study revealed that most of the sites in Bukit Ibam and Kuala Lipis were categorized as clean to slightly polluted. On the other hand, heavy metal analysis in water showed that aluminium and manganese level in both sites have exceeded the allowable limits for raw and treated water standards by the Ministry of Health. For heavy metal compositions in soils showed most of the heavy metal concentrations were below the recommended guideline values except for lead, arsenic, zinc and copper.

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

    Directory of Open Access Journals (Sweden)

    Yulieth C. Reyes

    2016-07-01

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

  1. Microbial activity in the terrestrial subsurface

    International Nuclear Information System (INIS)

    Kaiser, J.P.; Bollag, J.M.

    1990-01-01

    Little is known about the layers under the earth's crust. Only in recent years have techniques for sampling the deeper subsurface been developed to permit investigation of the subsurface environment. Prevailing conditions in the subsurface habitat such as nutrient availability, soil composition, redox potential, permeability and a variety of other factors can influence the microflora that flourish in a given environment. Microbial diversity varies between geological formations, but in general sandy soils support growth better than soils rich in clay. Bacteria predominate in subsurface sediments, while eukaryotes constitute only 1-2% of the microorganisms. Recent investigations revealed that most uncontaminated subsurface soils support the growth of aerobic heteroorganotrophic bacteria, but obviously anaerobic microorganisms also exist in the deeper subsurface habitat. The microorganisms residing below the surface of the earth are capable of degrading both natural and xenobiotic contaminants and can thereby adapt to growth under polluted conditions. (author) 4 tabs, 77 refs

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

    International Nuclear Information System (INIS)

    Lavoie, Isabelle; Lavoie, Michel; Fortin, Claude

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-03-01

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

  4. 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.

  5. Quantifying 12/13CH4 migration and fate following sub-surface release to an agricultural soil

    International Nuclear Information System (INIS)

    Shaw, G.; Atkinson, B.; Meredith, W.; Snape, C.; Steven, M.; Hoch, A.; Lever, D.

    2014-01-01

    Following gas generation in a Geological Disposal Facility (GDF), 14 C-containing gases could migrate through the geosphere, eventually diffusing into soils at the Earth's surface. This paper reports summary results from laboratory and field experiments to obtain information on the probable rates of a) diffusive transport and b) oxidation of 12/13 CH 4 (as a surrogate for 14 CH 4) in a typical agricultural soil in the UK. Rates of CH 4 oxidation were generally low in the field and undisturbed soil columns, though a re-packed column of homogenised topsoil oxidised ambient atmospheric CH 4 20× faster than an undisturbed soil column. In contrast to low observed rates of CH 4 oxidation, the effective diffusion of CH 4 through the soil was rapid. Isotopically labelled CH 4 injected at a depth of 45 cm in the field diffused to the surface and exited the soil over a time period ranging from 8 to 24 h. The rate of CH 4 diffusion through the soil was increased by the presence of ryegrass roots which increased soil porosity and decreased water content. δ 13 C values for laboratory column soils after labelled CH 4 injection experiments showed no sign of residual 13 C, despite the extremely high δ 13 C values of the injected 12/13 CH 4 . If laboratory observations are confirmed by measurements in field samples it can be concluded that the majority of 14 CH 4 from a GDF which enters a soil with low methanotrophic activity will be lost to the free atmosphere after diffusing rapidly through the soil column

  6. Estabelecimento de plantas herbáceas em solo com contaminação de metais pesados e inoculação de fungos micorrízicos arbusculares Establishment of herbaceous plants in heavy metal contaminated soils inoculated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Carbone Carneiro

    2001-12-01

    Full Text Available Neste trabalho estudou-se o estabelecimento de plantas herbáceas em solo com contaminação de metais pesados (MP e inoculação de fungos micorrízicos arbusculares (FMAs. O experimento foi realizado em bandejas, em esquema fatorial 5 x 2, sendo cinco proporções de solo contaminado com MP na ausência e presença de FMAs. Sementes de oito espécies de gramíneas e uma crucífera (mostarda -- Brassica sp. foram plantadas e cultivadas por 120 dias e avaliadas em dois cortes. No primeiro corte, as gramíneas foram severamente afetadas pela contaminação, e a mostarda foi pouco afetada, mostrando alta tolerância. No segundo corte, o efeito da contaminação foi negligível para as gramíneas, e a inoculação dos FMAs aumentou em 24% a matéria seca destas em relação ao controle sem inoculação. A inoculação teve também efeito positivo na matéria seca das raízes e na colonização micorrízica. Os teores de Cd, Zn e Pb na parte aérea foram maiores na mostarda do que nas gramíneas em ambos os cortes. Apesar de a inoculação não ter efeito no crescimento das gramíneas do primeiro corte, as plantas com inoculação apresentaram maior acúmulo de Zn, Cd e Pb no segundo corte. A maior tolerância da mostarda aos metais pesados permitiu seu crescimento e conseqüente acúmulo de Zn, Cd e Pb do solo contaminado. A extração destes elementos do solo pode ter contribuído para o melhor desenvolvimento subseqüente das gramíneas, favorecendo o estabelecimento das plantas.The establishment of herbaceous plants in soil contaminated by heavy metals (HM and inoculated with arbuscular mycorrhizal fungi (AMF was evaluated in the present study. The experiment was conducted in trays, in a 5 x 2 factorial, being five proportions of contaminated soil with or without inoculation with arbuscular mycorrhizal fungi (AMF. Seeds of eight grass species and a mustard (Brassica sp. were planted and allowed to grow for 120 days under greenhouse conditions

  7. Subsurface probing

    International Nuclear Information System (INIS)

    Lytle, R.J.

    1978-01-01

    Imaging techniques that can be used to translate seismic and electromagnetic wave signals into visual representation are briefly discussed. The application of these techniques is illustrated on the example of determining the subsurface structure of a proposed power plant. Imaging makes the wave signals intelligible to the non-geologists. R and D work needed in this area are tabulated

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

    Science.gov (United States)

    Chon, Hyo-Taek

    2017-04-01

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

  9. Responses and Remediating Effects of Pennisetum hydridum to Application of Heavy-Metals-Contaminated Chicken Manures and Sewage Sludges

    Directory of Open Access Journals (Sweden)

    WANG Xi-na

    2015-10-01

    Full Text Available Pennisetum hydridum is a rapid growth, large biomass and multi-stress resistant plant. A pot experiment was carried out to investigate the bioremediation effects of P. hydridum by 2 kg heavy metal (Cd, Cu, Pb, and Zn contaminated chicken manure or sewage sludge mixing with 18 kg of lateritic red soil. The growth and heavy metal uptake of P. hydridum were measured in order to assess the phytoremediation potential. Results showed that P. hydridum growed well in all treatments and the best appeared in chicken manure. The biomass of plant in treatments with chicken manure, sewage sludge, and the control was 736.56±29.21, 499.99±32.01 g·pot-1, and 466.89±37.08 g·pot-1, respectively. The heavy metals in the soils were reduced significantly at the 200 d after planting P. hydridum in fall. The removing percentage of total Zn, Cu, Pb, and Cd in soil was 1.90%~4.52%, 3.96%~5.72%, 0.53%~1.24% and 10.34%~17.14% respectively. The best effect of removing Zn, Cd and Pb appeared in chicken manure treatment was 89.74, 0.68 mg and 19.18 mg. The best effect of removing Cu appeared in sludge treatment was 16.84 mg. The results indicated that P. hydridum could be used for removement of the heavy metals from the heavy metal contaminated soils which could be considered as an potential plant for bioremediation of heavy metals.

  10. Effects of Metal Phytoextraction Practices on the Indigenous Community of Arbuscular Mycorrhizal Fungi at a Metal-Contaminated Landfill

    Science.gov (United States)

    Pawlowska, Teresa E.; Chaney, Rufus L.; Chin, Mel; Charvat, Iris

    2000-01-01

    Phytoextraction involves use of plants to remove toxic metals from soil. We examined the effects of phytoextraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays) and a factorial variation of soil amendments (either an ammonium or nitrate source of nitrogen and the presence or absence of an elemental sulfur supplement) on arbuscular mycorrhizal (AM) fungi (Glomales, Zygomycetes) at a moderately metal-contaminated landfill located in St. Paul, Minn. Specifically, we tested whether the applied treatments affected the density of glomalean spores and AM root colonization in maize. Glomalean fungi from the landfill were grouped into two morphotypes characterized by either light-colored spores (LCS) or dark-colored spores (DCS). Dominant species of the LCS morphotype were Glomus mosseae and an unidentified Glomus sp., whereas the DCS morphotype was dominated by Glomus constrictum. The density of spores of the LCS morphotype from the phytoremediated area was lower than the density of these spores in the untreated landfill soil. Within the experimental area, spore density of the LCS morphotype in the rhizosphere of mycorrhizal maize was significantly higher than in rhizospheres of nonmycorrhizal S. vulgaris or T. caerulescens. Sulfur supplement increased vesicular root colonization in maize and exerted a negative effect on spore density in maize rhizosphere. We conclude that phytoextraction practices, e.g., the choice of plant species and soil amendments, may have a great impact on the quantity and species composition of glomalean propagules as well as on mycorrhiza functioning during long-term metal-remediation treatments. PMID:10831433

  11. Study of the effect of wind speed on evaporation from soil through integrated modeling of the atmospheric boundary layer and shallow subsurface.

    Science.gov (United States)

    Davarzani, Hossein; Smits, Kathleen; Tolene, Ryan M; Illangasekare, Tissa

    2014-01-01

    In an effort to develop methods based on integrating the subsurface to the atmospheric boundary layer to estimate evaporation, we developed a model based on the coupling of Navier-Stokes free flow and Darcy flow in porous medium. The model was tested using experimental data to study the effect of wind speed on evaporation. The model consists of the coupled equations of mass conservation for two-phase flow in porous medium with single-phase flow in the free-flow domain under nonisothermal, nonequilibrium phase change conditions. In this model, the evaporation rate and soil surface temperature and relative humidity at the interface come directly from the integrated model output. To experimentally validate numerical results, we developed a unique test system consisting of a wind tunnel interfaced with a soil tank instrumented with a network of sensors to measure soil-water variables. Results demonstrated that, by using this coupling approach, it is possible to predict the different stages of the drying process with good accuracy. Increasing the wind speed increases the first stage evaporation rate and decreases the transition time between two evaporative stages (soil water flow to vapor diffusion controlled) at low velocity values; then, at high wind speeds the evaporation rate becomes less dependent on the wind speed. On the contrary, the impact of wind speed on second stage evaporation (diffusion-dominant stage) is not significant. We found that the thermal and solute dispersion in free-flow systems has a significant influence on drying processes from porous media and should be taken into account.

  12. Heavy metal contamination and its indexing approach for groundwater of Goa mining region, India

    Science.gov (United States)

    Singh, Gurdeep; Kamal, Rakesh Kant

    2017-06-01

    The objective of the study is to reveal the seasonal variations in the groundwater quality with respect to heavy metal contamination. To get the extent of the heavy metals contamination, groundwater samples were collected from 45 different locations in and around Goa mining area during the monsoon and post-monsoon seasons. The concentration of heavy metals, such as lead, copper, manganese, zinc, cadmium, iron, and chromium, were determined using atomic absorption spectrophotometer. Most of the samples were found within limit except for Fe content during the monsoon season at two sampling locations which is above desirable limit, i.e., 300 µg/L as per Indian drinking water standard. The data generated were used to calculate the heavy metal pollution index (HPI) for groundwater. The mean values of HPI were 1.5 in the monsoon season and 2.1 in the post-monsoon season, and these values are well below the critical index limit of 100.

  13. Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

    2008-12-30

    This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

  14. Trace metal contamination in mangrove sediments, Guanabara Bay, Rio de Janeiro, Brazil

    OpenAIRE

    Farias,Cassia O.; Hamacher,Claudia; Wagener,Angela de Luca R.; Campos,Reinaldo C. de; Godoy,José M.

    2007-01-01

    The Guanabara Bay in Rio de Janeiro has undergone profound alterations of its natural environmental conditions. Metal concentration increase in sediments has been reported to be among these alterations. Trace-metal contamination and availability were studied in sediments of 3 mangrove areas of the bay. Cd, Zn, Pb, Ni, Cu and Al concentrations were determined in segments of sediment cores, after treatment with 1 mol L-1 HCl and with concentrated HNO3. Fe and Mn were determined in the leach wit...

  15. Migracija dizel goriva izlivenog u slojeve zemljišta / Migration of diesel fuel spilled in subsurface layers of soil

    Directory of Open Access Journals (Sweden)

    Mladen Vuruna

    2005-09-01

    Full Text Available U radu su prikazane osnovne fizičko-hemijske karakteristike dizel goriva i zemljišta. Objašnjena je migracija izlivenog naftnog zagađivača kroz vertikalni profil zemljišta. U eksperimentalnom delu ispitivane su koncentracije dizel goriva i relativne koncentracije n-alkana u površinskim slojevima peska, u koje gorivo dospeva kao posledica akcidentnog izlivanja. Utvrđeno je da se koncentracije dizel goriva menjaju sa vremenom nakon izlivanja u svim ispitivanim slojevima. Takođe, utvrđeno je da se dizel gorivo, kao potencijalni zagađivač, u prvih šest nedelja, uglavnom, zadržava u površinskom sloju dubine 30 cm, a objašnjene su i mogućnosti sanacije zagađenog zemljišta. / The basic physical and chemical properties of both diesel fuel and soil have been given in this article and oil pollutants migration through vertical soil profile have been explained as well. In the experimental part of the paper both the concentrations of diesel fuel and relative concentrations of n-alkynes spilled in sandy soil by accident have been investigated. It has been proven that the concentrations of diesel fuel have changed in all layers of soil depending on the time after spill. Diesel fuel as possible pollutant has been retained 30 cm deep in sandy soil during six weeks after spill. Finally, cleanup techniques of polluted soil have been explained.

  16. A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    International Nuclear Information System (INIS)

    Gao Baohong; Liu Yuling; Wang Chenwei; Wang Shengli; Zhou Qiang; Tan Baimei; Zhu Yadong

    2010-01-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO 4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection. (semiconductor technology)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  19. Subsurface contaminants focus area

    International Nuclear Information System (INIS)

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites

  20. Subsurface contaminants focus area

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

  1. Use of soil moisture dynamics and patterns at different spatio-temporal scales for the investigation of subsurface flow processes

    Directory of Open Access Journals (Sweden)

    T. Blume

    2009-07-01

    Full Text Available Spatial patterns as well as temporal dynamics of soil moisture have a major influence on runoff generation. The investigation of these dynamics and patterns can thus yield valuable information on hydrological processes, especially in data scarce or previously ungauged catchments. The combination of spatially scarce but temporally high resolution soil moisture profiles with episodic and thus temporally scarce moisture profiles at additional locations provides information on spatial as well as temporal patterns of soil moisture at the hillslope transect scale. This approach is better suited to difficult terrain (dense forest, steep slopes than geophysical techniques and at the same time less cost-intensive than a high resolution grid of continuously measuring sensors. Rainfall simulation experiments with dye tracers while continuously monitoring soil moisture response allows for visualization of flow processes in the unsaturated zone at these locations. Data was analyzed at different spacio-temporal scales using various graphical methods, such as space-time colour maps (for the event and plot scale and binary indicator maps (for the long-term and hillslope scale. Annual dynamics of soil moisture and decimeter-scale variability were also investigated. The proposed approach proved to be successful in the investigation of flow processes in the unsaturated zone and showed the importance of preferential flow in the Malalcahuello Catchment, a data-scarce catchment in the Andes of Southern Chile. Fast response times of stream flow indicate that preferential flow observed at the plot scale might also be of importance at the hillslope or catchment scale. Flow patterns were highly variable in space but persistent in time. The most likely explanation for preferential flow in this catchment is a combination of hydrophobicity, small scale heterogeneity in rainfall due to redistribution in the canopy and strong gradients in unsaturated conductivities leading to

  2. Feasibility study of X-ray K-edge analysis of RCRA heavy metal contamination of sludge packaged in drums

    International Nuclear Information System (INIS)

    Jensen, T.

    1999-01-01

    A study has been completed to assess the capabilities of X-ray K-edge analysis in the measurement of RCRA metal contamination of sludge packaged in drums. Results were obtained for mercury and lead contamination. It was not possible to measure cadmium contamination using this technique. No false positive signals were observed. In cases where uniformity of the sludge can be assumed, this analysis can provide a quick, accurate measurement of heavy-metal contamination

  3. PHYSICO-CHEMICAL PROPERTIES OF THE SOLID AND LIQUID WASTE PRODUCTS FROM THE HEAVY METAL CONTAMINATED ENERGY CROPS GASIFICATION PROCESS

    Directory of Open Access Journals (Sweden)

    Sebastian Werle

    2017-02-01

    Full Text Available The paper presents the results of basic physico-chemical properties of solid (ash and liquid (tar waste products of the gasification process of the heavy metal contaminated energy crops. The gasification process has carried out in a laboratory fixed bed reactor. Three types of energy crops: Miscanthus x giganteus, Sida hermaphrodita and Spartina Pectinata were used. The experimental plots were established on heavy metal contaminated arable land located in Bytom (southern part of Poland, Silesian Voivodship.

  4. Nitrification and nitrogen mineralization in agricultural soils contaminated by copper mining activities in Central Chile

    OpenAIRE

    Moya, Héctor; Verdejo, José; Yáñez, Carolina; Álvaro, Juan E.; Sauvé, Sébastien; Neaman, Alexander

    2017-01-01

    Microbiological bioassays of nitrification and nitrogen mineralization have been used for evaluation of soil quality on metal-contaminated soils. We evaluated the effectiveness of nitrification and nitrogen mineralization bioassays as quality indicators of soil degradation caused by metal contamination. We performed standard tests based on protocols of ISO 14238 (2012) and ISO 15685 (2012) on 90 soil samples collected from agricultural areas in central Chile that were historically contaminate...

  5. Distribuição de água no solo aplicado por gotejamento enterrado e superficial Soil water distribution for subsurface and surface drip irrigation

    Directory of Open Access Journals (Sweden)

    Allan C. Barros

    2009-12-01

    Full Text Available Devido à falta de estudos sobre o movimento da água quando aplicada abaixo da superfície, realizou-se este trabalho com o objetivo de avaliar a distribuição de água aplicada pelo sistema de gotejamento enterrado e convencional. O experimento de campo foi conduzido na área experimental do Departamento de Engenharia Rural da ESALQ/USP - Piracicaba, SP. Para o estudo, trincheiras foram abertas e instaladas sondas de TDR, dispostas a 0,05; 0,15; 0,25; 0,35 e 0,45 m profundidade, e a 0,05; 0,15; 0,25; 0,35 m comprimento, totalizando 17 sondas por trincheira. Os tratamentos foram baseados na profundidade de aplicação (0,0 e 0,10 m e vazão aplicada (2 e 4 L h-1: ENT2; ENT4; SUP2 e SUP4. A cada hora era aplicado 1 L de água (total de 10 L, seguida de leituras com o TDR. Medições do disco úmido e saturado foram feitas com régua milimetrada; além disso, estabeleceu-se um volume controle onde foi avaliada a uniformidade de aplicação; assim, foi possível verificar, em relação aos sistemas superficiais, que os sistemas enterrados apresentaram menor área superficial molhada e atingiram maior largura e profundidade; já as maiores concentrações foram obtidas próximas ao ponto de emissão.Studies of sub-surface water movement is an interesting topic in irrigation but, in spite of the its importance, there is little literature. One of the purposes of this study was to contribute to this subject and evaluate the distribution of water applied by both subsurface drip irrigation (SDI and conventional irrigation. Experiments were conducted at the Department of Rural Engineering (ESALQ/USP, located at Piracicaba, SP. Trenches were opened and 17 three-rod TDR probes were installed, placed at 0.05, 0.15, 0.25, 0.35 and 0.45 m depths, and to 0.05, 0.15, 0.25, 0.35 m intervals. This procedure was repeated using a dripper buried at 0 and 0.10 m for each discharge rate of 2 and 4 L h-1 tested. Wetted soil volume was observed with 1 L of water

  6. Soil invertebrates as bioindicators of urban soil quality

    International Nuclear Information System (INIS)

    Santorufo, Lucia; Van Gestel, Cornelis A.M.; Rocco, Annamaria; Maisto, Giulia

    2012-01-01

    This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. - Highlights: ► The abundance and diversity of invertebrate communities was related to properties and metal contents of urban soils. ► Several (biodiversity) indices were calculated and compared to evaluate soil quality. ► Metal contamination affected invertebrate density and diversity. ► The taxa more tolerant to metal contamination were Acarina, Enchytraeids, Collembola and Nematoda. ► The soil biological quality index QBS index was most appropriate for soil quality assessment. - Soil metal contamination negatively affected soil invertebrate abundance and diversity.

  7. Modeling Adsorption Kinetics (Bio-remediation of Heavy Metal Contaminated Water)

    Science.gov (United States)

    McCarthy, Chris

    My talk will focus on modeling the kinetics of the adsorption and filtering process using differential equations, stochastic methods, and recursive functions. The models have been developed in support of our interdisciplinary lab group which is conducting research into bio-remediation of heavy metal contaminated water via filtration through biomass such as spent tea leaves. The spent tea leaves are available in large quantities as a result of the industrial production of tea beverages. The heavy metals bond with the surfaces of the tea leaves (adsorption). Funding: CUNY Collaborative Incentive Research Grant.

  8. Acidification and heavy metal contamination in the border area Norway/Russia. Annual report 1995; Forsuring og tungmetallforurensning i grenseomraadene Norge/Russland. Aarsrapport for 1995

    Energy Technology Data Exchange (ETDEWEB)

    Traaen, T.S.; Rognerud, S.

    1996-12-31

    According to this report, water-chemical monitoring of lakes in Southern Varanger has in recent years shown a marked decrease in the concentrations of sulphate and labile aluminium and increasing pH and ANC. The reason is that the reduced emission from the Pechenga-Nikel Company in Russia has led to less sulphur deposition in Norway. It is found that the water quality in the lakes in the area rapidly improves when the sulphur deposition decreases. There is no clear evidence for changes in the concentrations of nickel and copper in the lakes. The concentrations of Ni and Cu in lake sediments and in soil will probably be increasing steadily and the heavy metal contamination should be continuously monitored. 16 refs., 9 figs., 6 tabs.

  9. Application of portable X-ray fluorescence spectrometry in environmental investigation of heavy metal-contaminated sites and comparison with laboratory analysis

    Science.gov (United States)

    Ding, Liang; Wang, Shui; Cai, Bingjie; Zhang, Mancheng; Qu, Changsheng

    2018-02-01

    In this study, portable X-ray fluorescence spectrometry (pXRF) was used to measure the heavy metal contents of As, Cu, Cr, Ni, Pb and Zn in the soils of heavy metal-contaminated sites. The precision, accuracy and system errors of pXRF were evaluated and compared with traditional laboratory methods to examine the suitability of in situ pXRF. The results show that the pXRF analysis achieved satisfactory accuracy and precision in measuring As, Cr, Cu, Ni, Pb, and Zn in soils, and meets the requirements of the relevant detection technology specifications. For the certified reference soil samples, the pXRF results of As, Cr, Cu, Ni, Pb, and Zn show good linear relationships and coefficients of determination with the values measured using the reference analysis methods; with the exception of Ni, all the measured values were within the 95% confidence level. In the soil samples, the coefficients of determination between Cu, Zn, Pb, and Ni concentrations measured laboratory pXRF and the values measured with laboratory analysis all reach 0.9, showing a good linear relationship; however, there were large deviations between methods for Cr and As. This study provides reference data and scientific support for rapid detection of heavy metals in soils using pXRF in site investigation, which can better guide the practical application of pXRF.

  10. Heavy metal contamination in agricultural soils and water in Dar es ...

    African Journals Online (AJOL)

    African Journal of Environmental Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 11 (2010) >. Log in or Register to get access to full text downloads.

  11. MOBILE ATOMIC ABSORPTION SPECTROMETER OPERATED BY PACE ENVIRONMENTAL FOR METALS-CONTAMINATED SOIL CHARACTERIZATION

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA), through the Environmental Technology Verification Program, is working to accelerate the acceptance and use of innovative technologies that improve the way the United States manages its environmental problems. This report describes ...

  12. Heavy metal contamination in agricultural soils and water in Dar es ...

    African Journals Online (AJOL)

    USER

    Department of Environmental Science and Management, Ardhi University, P. O. Box 35176, Dar es Salaam, Tanzania. Accepted 20 ... opportunities, demand for food, proximity to markets and ... serious environmental and public health effects. One of ... concentrations they can lead to poisoning (Cambra et al.,. 1999).

  13. The inter