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Sample records for heavy soil conditions

  1. Soils affected by heavy metals due to old mining on perudic conditions

    NASA Astrophysics Data System (ADS)

    Garrigo, Jordi; Elustondo, David; Laheras, Ester; Oiarzabal, Maite; Jaume, Bech

    2010-05-01

    The aim of this work is to assess the actual status of the soils of a natural environment surrounding an abandoned mine (exploited since the Roman Age) where Pb, Zn, Fe and Cu were obtained. The study has been carried out in the Aitzondo valley (Guipuzkoa, North of Iberian Peninsula), which cross the exploited mountainous area with middle temperatures and perudic soil moisture regime Soils in the valley are polygenic, acids, very washed and sometimes show redoximorphic features and have undergone a great mobilization of trace metals due to these physical-chemical characteristics that enhance the heavy metals solubility and mobility. The analysis of soil surface samples shows a punctual and intense pollution at Meazuri area (where the mine is located) and another more dispersal and wide pollution due to the parent material (Palaeozoic shales). The main soil type of the area has been characterized by means of the performance of a soil and six surface samples have been collected along an altitudinal transect, which goes down from 460 to 75 meters. Both profile and surface samples have been analysed for suitable parameters due to their repercussion in mobility and fixation of some heavy metals (organic matter, clay content…). Total (Na, K, Mg, Ca, Al, Fe, Mn, Ti, Cd, Cr) and extractable fraction (using NH4Ac-EDTA pH=4.65, as extracting agent, have been analysed. Trace elements Cd, Cr, Cu, Ni, Pb and Zn have been measured. On summary, the soils studied are characterized by high levels of trace metals inherited from the parent material whose composition shows a great metallic richness. Hence, values of trace metals are very high even in remote areas where there has not been anthropic influence. Besides, the physical-chemical properties (acidity, base saturation, organic matter) have enhanced the mobility of trace metals. The anthropogenic activity (mining activity) has caused an increase in values of several metals, reaching, in some cases, concentrations above the

  2. Effect of heavy metals on soil enzyme activity at different field conditions in Middle Spis mining area (Slovakia).

    PubMed

    Angelovičová, Lenka; Lodenius, Martin; Tulisalo, Esa; Fazekašová, Danica

    2014-12-01

    Heavy metals concentrations were measured in the former mining area located in Hornad river valley (Slovakia). Soil samples were taken in 2012 from 20 sites at two field types (grasslands, heaps of waste material) and two different areas. Total content of heavy metals (Cu, Pb, Zn, Hg), urease (URE), acid phosphatase (ACP), alkaline phosphatase (ALP), soil reaction (pH) were changing depending on the field/area type. The tailing pond and processing plants have been found as the biggest sources of pollution. URE, ACP and ALP activities significantly decreased while the heavy metal contents increased. Significant differences were found among area types in the heavy metal contents and activity of URE. No statistical differences in the content of heavy metals but significant statistical differences for soil pH were found for field types (grassland and heaps). Significant negative correlation was found for URE-Pb, URE-Zn and also between soil reaction and ACP and ALP.

  3. Effects of heavy metal pollution from mining and smelting on enchytraeid communities under different land management and soil conditions.

    PubMed

    Kapusta, Paweł; Sobczyk, Łukasz

    2015-12-01

    We studied enchytraeid communities in several habitats polluted by heavy metals from Zn-Pb mining and smelting activities. We sampled 41 sites that differed in the type of substratum (carbonate rock, metal-rich carbonate mining waste, siliceous sand) and land management (planting Scots pine, topsoiling, leaving to natural succession), and the distance from the smelter. Our main aims were to determine which pollution variables and natural factors most influenced enchytraeid species composition, richness and density, and examine what was the effect of planting Scots pine (reclamation) on enchytraeid communities. The soils harboured on average 1 to 5 enchytraeid species and 700 to 18,300 individuals per square metre, depending on the habitat. These figures were generally lower than those reported from unpolluted regions. Redundancy and multiple regression analyses confirmed the negative impact of heavy metal pollution on both enchytraeid community structure and abundance. Among pollution variables, the distance from the smelter best explained the variation in enchytraeid communities. The concentrations of heavy metals in the soil had less (e.g. total Pb and exchangeable Zn) or negligible (water-soluble forms) explanatory power. Natural soil properties were nearly irrelevant for enchytraeids, except for soil pH, which determined the species composition. Plant species richness was an important explanatory variable, as it positively affected most parameters of enchytraeid community. The results of two-by-two factorial comparisons (planting Scots pine vs. natural succession; carbonate mining waste vs. siliceous sand) suggest that reclamation can improve soil quality for biota, since it increased the diversity and abundance of enchytraeids; this effect was not dependent on the type of substratum. In conclusion, enchytraeids responded negatively to heavy metal pollution and their response was consistent and clear. These animals can be used as indicators of metal toxicity

  4. Accumulation of heavy metals in soils and plants of Polar Urals and South Chukotka in contrast geochemical conditions in connection with the search for hyperaccumulator species

    NASA Astrophysics Data System (ADS)

    Alexeeva-Popova, Natalja Vadimovna; Bech, Jaume; Drozdova, Irina Valeryevna; Roca, Núria

    2017-04-01

    This study highlights the heavy metals (HM) distribution in soils and their uptake by wild plants that grow to the soils formed on the ultramafic and acid rocks of Polar Urals and South Chukotka in Arctic Russia. The contents of Fe, Mn, Zn, Cu, Ni, Cr, and Co have been determined by the atomic absorption spectrometry more than in 100 plant species of 25 families and in 92 soil samples. The data indicate that the levels of Fe, Cr and especially Ni in the soils on the ultramafic rocks exceeded those on acid rocks. It has been found that the mineral composition of plant species varies depending on edaphic conditions. Greater variability was noticed in the uptake of HM by various plant species on the studied soils. Taxon-specific features in the accumulation of heavy metals in plants of these regions have been revealed for the first time. Plants accumulation results showed that species Thlaspi cochleariforme and Alyssum obovatum (Brassicaceae) could act as hyperaccumulators Ni. The excessive concentrations of Cr and Ni in some plants species can be used for mineral prospecting. The excess of Ni is serious environmental problem and health risks in the inhabitants of the study areas.

  5. Effect of heavy metals on soil fungi

    NASA Astrophysics Data System (ADS)

    Sosak-Świderska, Bożena

    2010-05-01

    Fungi constitute a high proportion of the microbial biomass in soil.Being widespread in soil their large surface-to-volume ratio and high metabolic activity, fungi can contribute significantly to heavy metal dynamics in soil. At neutral pH heavy metals in soils tend to be immobilized to precipitation and/or absorption to cation exchange sites of clay minerals. In the acidic soils, metals are more mobile and enter food webs easier. Microbial production of acids and chelating agents can mobilize to toxic metals. Mobilization is often by uptake and intracellular accumulation of the heavy metlas, and in this way, the bioavailability of metals towards other organisms can be more reduced. Fungi were isolated from soils from Upper Silesia in Poland and belonged to widespread genera: Aspergillus, Cladosporium, Penicillium and Trichoderma. Fungi from different taxonomic groups differ greatly in their tolerance to heavy metals. This could be related to their wall structure and chemistry as well as biochemical and physiological characteristics of fungi. Localization of metals in fungal cells was studied using electron microscopy analysis. Metal biosorption in the cell wall can be complex as melanin granules. Fungal vacuoles have an important role in the regulation of the cytosolic concentration of metal ions, and may contribute to heavy metal tolerance.In polluted soils with heavy metals, fungal species composition can be changed and their physiological activity can be changed, too.

  6. Modeling of Heavy Metal Transformation in Soil Ecosystem

    NASA Astrophysics Data System (ADS)

    Kalinichenko, Kira; Nikovskaya, Galina N.

    2017-04-01

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

  7. Quantitative assessment of the toxic effects of heavy metals on 1,2-dichloroethane biodegradation in co-contaminated soil under aerobic condition.

    PubMed

    Olaniran, Ademola Olufolahan; Balgobind, Adhika; Pillay, Balakrishna

    2011-10-01

    1,2-Dichloroethane (1,2-DCA) is one of the most hazardous pollutant of soil and groundwater, and is produced in excess of 5.44×10⁹ kg annually. Owing to their toxicity, persistence and potential for bioaccumulation, there is a growing interest in technologies for their removal. Heavy metals are known to be toxic to soil microorganisms at high concentrations and can hinder the biodegradation of organic contaminants. In this study, the inhibitory effect of heavy metals, namely; arsenic, cadmium, mercury and lead, on the aerobic biodegradation of 1,2-DCA by autochthonous microorganisms was evaluated in soil microcosm setting. The presence of heavy metals was observed to have a negative impact on the biodegradation of 1,2-DCA in both soil samples tested, with the toxic effect being more pronounced in loam soil, than in clay soil. Generally, 75 ppm As³⁺, 840 ppm Hg²⁺, and 420 ppm Pb²⁺ resulted in 34.24%, 40.64%, and 45.94% increase in the half live (t½) of 1,2-DCA, respectively, in loam soil, while concentrations above 127.5 ppm Cd²⁺, 840 ppm Hg²⁺ and 420 ppm of Pb²⁺ and less than 75 ppm As³⁺ was required to cause a >10% increase in the t½ of 1,2-DCA in clay soil. A dose-dependent relationship between degradation rate constant (k₁) of 1,2-DCA and metal ion concentrations was observed for all the heavy metals tested, except for Hg²⁺. This study demonstrated that different heavy metals have different impacts on the degree of 1,2-DCA degradation. Results also suggest that the degree of inhibition is metal specific and is also dependent on several factors including; soil type, pH, moisture content and available nutrients. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Stabilize heavy metals in soils and sludges

    SciTech Connect

    1995-03-01

    To stabilize heavy metals in soils, sludges, ash from incinerators and power plants, and baghouse dusts, Solucorp Industries (Saddle Brook, N.J.) has developed the Molecular Bonding System (MBS). Using a patented mix of chemical additives, the MBS process bonds highly reactive metal ions to form non-leachable molecules, rendering the metals inert. The chemical reactions are said to be permanent, and for each application, the additive mix is specially formulated to meet site-specific conditions. Recently, the MBS process was accepted into the US Environmental Protection Agency`s Site Demonstration Program as an innovative technology for stabilizing heavy metals. Bench-scale and pilot tests have proven the effectiveness of the MBS process for a wide array of metals, including arsenic, cadmium, chromium, copper, lead, mercury, nickel, silver and zinc. The process is designed for wastes classified as D004 through D011, as well as K-listed wastes associated with metal-plating operations. It can treat waste in drums or in bulk, says the firm, but is not suitable for liquid streams.

  9. [Effect of reclaimed water irrigation on soil properties and vertical distribution of heavy metal].

    PubMed

    Zhao, Zong-Ming; Chen, Wei-Ping; Jiao, Wen-Tao; Wang, Mei-E

    2012-12-01

    Utilization of reclaimed water is one of the important methods to alleviate water shortage. The effect of reclaimed water irrigation on soil is always a concern. To understand the effect of long time reclaimed water irrigation on soil, typical farmland irrigated with reused water was selected. Soil properties and heavy metal concentration of soil and water samples were analyzed to identify the effect of the irrigation on heavy metal vertical distribution and organic matter content, total carbon, total nitrogen and pH value in soil. The results show that heavy metal contents of irrigation water used in Liangshuihe farmland are 2.5 to 10.5 times higher than that of Beiyechang farmland, and reclaimed water irrigation could cause changes of soil properties that soil organic matter content, total carbon, total nitrogen were increased and pH values were reduced. Based on the field investigation results, the soil nutrient conditions benefit from irrigate reclaimed water, however, the accumulation of heavy metal in soil could raise the risk. As a source of soil heavy metal, reclaimed water irrigation could make differences on the accumulation and mobility of soil heavy metal. Also the distribution and mobility of soil heavy metal are influenced by soil organic matter content and there are more heavy metal were taken up by plants or transferred to the deeper area in Liangshuihe farmland.

  10. Natural and technogenic compounds of heavy metals in soils

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.

    2014-04-01

    The existing geological classification of heavy metals (HMs) is not suitable for their characterization in soils. The carriers of HMs in soils differ from those in the lithosphere. These are clay minerals; iron oxides, whose composition varies between the background and urban soils; various manganese oxides; and different groups of organic substances. The mineral composition of HM carriers can vary significantly. The main iron oxides are ferrihydrite, goethite, feroxyhyte, and lepidocrocite in the background soils and technogenic magnetite in the urban soils. The different structures of manganese oxides determine their affinity for specific HMs. Metallic iron and green rust are very efficient in artificial geochemical barriers, although they act as strong reducers there. HM compounds strongly vary in soils because of the unstable conditions.

  11. Magnetic properties of alluvial soils polluted with heavy metals

    NASA Astrophysics Data System (ADS)

    Dlouha, S.; Petrovsky, E.; Boruvka, L.; Kapicka, A.; Grison, H.

    2012-04-01

    Magnetic properties of soils, reflecting mineralogy, concentration and grain-size distribution of Fe-oxides, proved to be useful tool in assessing the soil properties in terms of various environmental conditions. Measurement of soil magnetic properties presents a convenient method to investigate the natural environmental changes in soils as well as the anthropogenic pollution of soils with several risk elements. The effect of fluvial pollution with Cd, Cu, Pb and Zn on magnetic soil properties was studied on highly contaminated alluvial soils from the mining/smelting district (Příbram; CZ) using a combination of magnetic and geochemical methods. The basic soil characteristics, the content of heavy metals, oxalate, and dithionite extractable iron were determined in selected soil samples. Soil profiles were sampled using HUMAX soil corer and the magnetic susceptibility was measured in situ, further detailed magnetic analyses of selected distinct layers were carried out. Two types of variations of magnetic properties in soil profiles were observed corresponding to indentified soil types (Fluvisols, and Gleyic Fluvisols). Significantly higher values of topsoil magnetic susceptibility compared to underlying soil are accompanied with high concentration of heavy metals. Sequential extraction analysis proved the binding of Pb, Zn and Cd in Fe and Mn oxides. Concentration and size-dependent parameters (anhysteretic and isothermal magnetization) were measured on bulk samples in terms of assessing the origin of magnetic components. The results enabled to distinguish clearly topsoil layers enhanced with heavy metals from subsoil samples. The dominance of particles with pseudo-single domain behavior in topsoil and paramagnetic/antiferromagnetic contribution in subsoil were observed. These measurements were verified with room temperature hysteresis measurement carried out on bulk samples and magnetic extracts. Thermomagnetic analysis of magnetic susceptibility measured on

  12. Remediation processes for heavy metals contaminated soils

    SciTech Connect

    Torma, G.A.; Torma, A.E.; Hsu, Pei-Cheng

    1996-12-31

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

  13. Solvent extraction for heavy crude oil removal from contaminated soils.

    PubMed

    Li, Xingang; Du, Yongliang; Wu, Guozhong; Li, Zhongyuan; Li, Hong; Sui, Hong

    2012-06-01

    A new strategy of heavy crude oil removal from contaminated soils was studied. The hexane-acetone solvent mixture was used to investigate the ability of solvent extraction technique for cleaning up soils under various extraction conditions. The mixtures of hexane and acetone (25 vol%) were demonstrated to be the most effective in removing petroleum hydrocarbons from contaminated soils and approx 90% of saturates, naphthene aromatics, polar aromatics, and 60% of nC(7)-asphaltenes were removed. Kinetic experiments demonstrated that the equilibrium was reached in 5 min and the majority of the oil pollutants were removed within 0.5 min. The effect of the ratio between solvent and soil on the extraction efficiency was also studied and results showed that the efficiency would increase following the higher solvent soil ratio. Then the multistage continuous extraction was considered to enhance the removal efficiency of oil pollutants. Three stages crosscurrent and countercurrent solvent extraction with the solvent soil ratio 6:1 removed 97% oil contaminants from soil. Clearly the results showed that the mixed-solvent of hexane and acetone (25 vol%) with character of low-toxic, acceptable cost and high efficiency was promising in solvent extraction to remove heavy oil fractions as well as petroleum hydrocarbons from contaminated soils. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Quantitative assessment on soil enzyme activities of heavy metal contaminated soils with various soil properties.

    PubMed

    Xian, Yu; Wang, Meie; Chen, Weiping

    2015-11-01

    Soil enzyme activities are greatly influenced by soil properties and could be significant indicators of heavy metal toxicity in soil for bioavailability assessment. Two groups of experiments were conducted to determine the joint effects of heavy metals and soil properties on soil enzyme activities. Results showed that arylsulfatase was the most sensitive soil enzyme and could be used as an indicator to study the enzymatic toxicity of heavy metals under various soil properties. Soil organic matter (SOM) was the dominant factor affecting the activity of arylsulfatase in soil. A quantitative model was derived to predict the changes of arylsulfatase activity with SOM content. When the soil organic matter content was less than the critical point A (1.05% in our study), the arylsulfatase activity dropped rapidly. When the soil organic matter content was greater than the critical point A, the arylsulfatase activity gradually rose to higher levels showing that instead of harm the soil microbial activities were enhanced. The SOM content needs to be over the critical point B (2.42% in our study) to protect its microbial community from harm due to the severe Pb pollution (500mgkg(-1) in our study). The quantitative model revealed the pattern of variation of enzymatic toxicity due to heavy metals under various SOM contents. The applicability of the model under wider soil properties need to be tested. The model however may provide a methodological basis for ecological risk assessment of heavy metals in soil.

  15. Chelant extraction of heavy metals from contaminated soils.

    PubMed

    Peters, R W

    1999-04-23

    , the soil was successfully treated passing both the Toxicity Characteristics Leaching Procedure (TCLP) and EPA Total Extractable Metal Limit. The final residual Pb concentration was about 300 mg/kg, with a corresponding TCLP of 1.5 mg/l. Removal of the exchangeable and carbonate fractions for Cu and Zn was achieved during the first extraction stage, whereas it required two extraction stages for the same fractions for Pb. Removal of Pb, Cu, and Zn present as exchangeable, carbonates, and reducible oxides occurred between the fourth- and fifth-stage extractions. The overall removal of copper, lead, and zinc from the multiple-stage washing were 98.9%, 98.9%, and 97.2%, respectively. The concentration and operating conditions for the soil washing extractions were not necessarily optimized. If the conditions had been optimized and using a more representative Pb concentration (approximately 12000 mg/kg), it is likely that the TCLP and residual heavy metal soil concentrations could be achieved within two to three extractions. The results indicate that the J-Field contaminated soils can be successfully treated using a soil washing technique. Copyright 1999 Published by Elsevier Science B.V.

  16. The influence of soil heavy metals pollution on soil microbial biomass, enzyme activity, and community composition near a copper smelter.

    PubMed

    Wang, YuanPeng; Shi, JiYan; Wang, Hui; Lin, Qi; Chen, XinCai; Chen, YingXu

    2007-05-01

    The environmental risk of heavy metal pollution is pronounced in soils adjacent to large industrial complexes. It is important to investigate the functioning of soil microorganisms in ecosystems exposed to long-term contamination by heavy metals. We studied the potential effects of heavy metals on microbial biomass, activity, and community composition in soil near a copper smelter in China. The results showed that microbial biomass C was negatively affected by the elevated metal levels and was closely correlated with heavy metal stress. Enzyme activity was greatly depressed by conditions in the heavy metal-contaminated sites. Good correlation was observed between enzyme activity and the distance from the smelter. Elevated metal loadings resulted in changes in the activity of the soil microbe, as indicated by changes in their metabolic profiles from correlation analysis. Significant decrease of soil phosphatase activities was found in the soils 200 m away from the smelter. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis demonstrated that heavy metals pollution had a significant impact on bacterial and actinomycetic community structure. There were negative correlations between soil microbial biomass, phosphatase activity, and NH(4)NO(3) extractable heavy metals. The soil microorganism activity and community composition could be predicted significantly using the availability of Cu and Zn. By combining different monitoring approaches from different viewpoints, the set of methods applied in this study were sensitive to site differences and contributed to a better understanding of heavy metals effects on the structure, size and activity of microbial communities in soils. The data presented demonstrate the role of heavy metals pollution in understanding the heavy metal toxicity to soil microorganism near a copper smelter in China.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  18. Effect of Drying on Heavy Metal Fraction Distribution in Rice Paddy Soil

    PubMed Central

    Qi, Yanbing; Huang, Biao; Darilek, Jeremy Landon

    2014-01-01

    An understanding of how redox conditions affect soil heavy metal fractions in rice paddies is important due to its implications for heavy metal mobility and plant uptake. Rice paddy soil samples routinely undergo oxidation prior to heavy metal analysis. Fraction distribution of Cu, Pb, Ni, and Cd from paddy soil with a wide pH range was investigated. Samples were both dried according to standard protocols and also preserved under anaerobic conditions through the sampling and analysis process and heavy metals were then sequentially extracted for the exchangeable and carbonate bound fraction (acid soluble fraction), iron and manganese oxide bound fraction (reducible fraction), organic bound fraction (oxidizable fraction), and residual fraction. Fractions were affected by redox conditions across all pH ranges. Drying decreased reducible fraction of all heavy metals. Curesidual fraction, Pboxidizable fraction, Cdresidual fraction, and Niresidual fraction increased by 25%, 33%, 35%, and >60%, respectively. Pbresidual fraction, Niacid soluble fraction, and Cdoxidizable fraction decreased 33%, 25%, and 15%, respectively. Drying paddy soil prior to heavy metal analysis overestimated Pb and underestimated Cu, Ni, and Cd. In future studies, samples should be stored after injecting N2 gas to maintain the redox potential of soil prior to heavy metal analysis, and investigate the correlation between heavy metal fraction distribution under field conditions and air-dried samples. PMID:24823670

  19. Effect of drying on heavy metal fraction distribution in rice paddy soil.

    PubMed

    Qi, Yanbing; Huang, Biao; Darilek, Jeremy Landon

    2014-01-01

    An understanding of how redox conditions affect soil heavy metal fractions in rice paddies is important due to its implications for heavy metal mobility and plant uptake. Rice paddy soil samples routinely undergo oxidation prior to heavy metal analysis. Fraction distribution of Cu, Pb, Ni, and Cd from paddy soil with a wide pH range was investigated. Samples were both dried according to standard protocols and also preserved under anaerobic conditions through the sampling and analysis process and heavy metals were then sequentially extracted for the exchangeable and carbonate bound fraction (acid soluble fraction), iron and manganese oxide bound fraction (reducible fraction), organic bound fraction (oxidizable fraction), and residual fraction. Fractions were affected by redox conditions across all pH ranges. Drying decreased reducible fraction of all heavy metals. Curesidual fraction, Pboxidizable fraction, Cdresidual fraction, and Niresidual fraction increased by 25%, 33%, 35%, and >60%, respectively. Pbresidual fraction, Niacid soluble fraction, and Cdoxidizable fraction decreased 33%, 25%, and 15%, respectively. Drying paddy soil prior to heavy metal analysis overestimated Pb and underestimated Cu, Ni, and Cd. In future studies, samples should be stored after injecting N2 gas to maintain the redox potential of soil prior to heavy metal analysis, and investigate the correlation between heavy metal fraction distribution under field conditions and air-dried samples.

  20. Heavy metal retention of different roadside soils

    NASA Astrophysics Data System (ADS)

    Werkenthin, Moritz; Kluge, Björn; Wessolek, Gerd

    2014-05-01

    Emissions from major highways contain different kinds of contaminants such as heavy metals, polycyclic aromatic hydrocarbons and road salts which can occur in both particulate and dissolved form. Pollutants are transferred to the environment via aerial transport or the infiltration of road runoff and spray water. A significant rate of the road runoff infiltrates into the Embankment which is usually built during road construction and located next to the road edge. Especially in the long term development there is an increasing problem of soil contamination and groundwater pollution. According to valid German law, newly constructed hard shoulders have to provide a specific bear-ing capacity to enable trafficability in emergency cases. Therefore the applicable materials consist of accurately defined gravel-soil mixtures, which can fulfil this requirement. To determine and com-pare the total and dissolved concentrations of Pb, Cd, Zn, Cu, Ni, Cr in the road runoff and seep-age water of newly constructed embankments, we installed 6 Lysimeter along the edge of the German highway A115. Three lysimeter were filled with different materials which are recently used for embankment construction in Germany. Three further lysimeter where installed and filled with plain gravel, to observe the distribution, quantity and quality of road runoff. Fist results showed that heavy metal concentrations determined in the road runoff were compara-ble to literature values. The solute concentrations in the seepage water of the different embank-ment materials do not show considerable differences and exceed the trigger values of the German Federal Soil Protection & Contamination Ordinance (BBodSchV) only sporadically. Total concentra-tions of the seepage water are significantly higher than solute concentrations and clearly differ be-tween stable and non stable variant. In order to estimate the risk of groundwater pollution further monitoring of seepage water quality is necessary.

  1. Effect of Water Logging Conditions on Solubility of Soil Nutrients

    USDA-ARS?s Scientific Manuscript database

    The wide use of herbicides, fungicides, fertilizers, and soil amendments affect the rhizosphere biochemistry and ecology. Soils in the Midwest of the US tend to be saturated in the early spring when snow and ice melt, and frequent rain occurs. Saturated conditions also occur after heavy rainfall eve...

  2. Heavy metals in soils of cocoa plantation (Theobroma cacao L.)

    USDA-ARS?s Scientific Manuscript database

    Cocoa has experienced significant growth in recent years in Peru and the presence of heavy metals in the soils of these plantations is a potential problem for the export of this product. Contents of heavy metals (Cd, Ni, Pb, Fe, Cu, Zn, Mn) in soils from 19 plantations that have been in production f...

  3. Using poly-glutamic acid as soil-washing agent to remediate heavy metal-contaminated soils.

    PubMed

    Yang, Zong-Han; Dong, Cheng-Di; Chen, Chiu-Wen; Sheu, Yih-Terng; Kao, Chih-Ming

    2017-05-20

    The extraction efficiency of heavy metals from soils using three forms of gamma poly-glutamic acid (γ-PGA) as the washing agents was investigated. Controlling factors including agent concentrations, extraction time, pH, and liquid to soil ratio were evaluated to determine the optimum operational conditions. The distribution of heavy metal species in soils before and after extraction processes was analyzed. Up to 46 and 74% of heavy metal removal efficiencies were achieved with one round and a sequential extraction process using H-bonding form of γ-PGA (200 mM) with washing time of 40 min, liquid to solid ratio of 10 to 1, and pH of 6. Major heavy metal removal mechanisms were (1) γ-PGA-promoted dissolution and (2) complexation of heavy metal with free carboxyl groups in γ-PGA, which resulted in heavy metal desorption from soils. Metal species on soils were redistributed after washing, and soils were remediated without destruction of soil structures and productivity.

  4. Influence of heavy metals on methane oxidation in tropical rice soils.

    PubMed

    Mohanty, S R; Bharati, K; Deepa, N; Rao, V R; Adhya, T K

    2000-11-01

    In a laboratory incubation study, the effect of select heavy metals on methane (CH4) oxidation in two rice soils was investigated under two moisture regimes. Heavy metals differed in their effect on CH4 oxidation in both soils under the two water regimes. Cr significantly inhibited CH4 oxidation in the alluvial soil at 60% moisture holding capacity, while Cu stimulated the process. On the contrary, Zn inhibited CH4 oxidation in both alluvial and laterite soils only under flooded conditions. Application of rice straw alleviated the inhibitory effect of heavy metals on CH4 oxidation and CO2 production. Inhibition of CH4 oxidation in the alluvial soil was related to the methanotrophic bacterial population in Cr- and Zn-amended alluvial soil.

  5. Effects of heavy metals on methane production in tropical rice soils.

    PubMed

    Mishra, S R; Bharati, K; Sethunathan, N; Adhya, T K

    1999-09-01

    In a laboratory incubation study, the effect of select heavy metals on methane (CH(4)) production in three rice soils was investigated under flooded conditions. Heavy metals behaved differently in their effect on methanogenesis in different soils and methane-producing bacteria. Cd, Cu, and Pb inhibited CH(4) production in all the soils. Zn stimulated CH(4) production in the alluvial soil, but inhibited it in laterite and acid sulfate soils. Cr effectively inhibited CH(4) production in the alluvial soil, but stimulated it in laterite and acid sulfate soils. The stimulatory effect of Zn and the inhibitory effect of Cr on methanogenesis in alluvial soil were attributed to their stimulation or inhibition of methanogenic bacterial population. Copyright 1999 Academic Press.

  6. Heavy Metal Pollution Enhances Soil Respiration and Reduces Carbon Storage in a Chinese Paddy Soil

    NASA Astrophysics Data System (ADS)

    Pan, Genxing; Li, Zhipeng; Liu, Yongzhuo; Smith, Pete; Crowley, David; Zheng, Jufeng

    2010-05-01

    China's paddy soils are crucial both for food security through high cereal productivity, and for climate mitigation through high soil carbon storage. These functions are increasingly threatened by widespread heavy metal pollution, resulting from rapid industrial development. Heavy metal-polluted soils generally have a reduced microbial biomass and reduced soil respiration, as well as reduced functional diversity through changes in microbial community structure. Here we show that heavy metal pollution enhances soil respiration and CO2 efflux from a Chinese rice paddy soil, and leads to a soil organic carbon (SOC) loss, which is correlated with a decline in the fungal-to-bacterial ratio of the reduced soil microbial community. The pollution-induced SOC loss could offset 70% of the yearly SOC increase from China's paddy soils. Thus, heavy metal pollution impacts long term productivity and the potential for C sequestration in China's paddy soils.

  7. Role of soil rhizobacteria in phytoremediation of heavy metal contaminated soils.

    PubMed

    Jing, Yan-de; He, Zhen-li; Yang, Xiao-e

    2007-03-01

    Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have received more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms involved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes.

  8. Role of soil rhizobacteria in phytoremediation of heavy metal contaminated soils*

    PubMed Central

    Jing, Yan-de; He, Zhen-li; Yang, Xiao-e

    2007-01-01

    Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have received more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms involved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes. PMID:17323432

  9. Isolation and characterization of heavy polycyclic aromatic hydrocarbon-degrading bacteria adapted to electrokinetic conditions.

    PubMed

    Li, Fengmei; Guo, Shuhai; Hartog, Niels; Yuan, Ye; Yang, Xuelian

    2016-02-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in artificially contaminated soils. The results showed that strains PB4 (Pseudomonas fluorescens) and FB6 (Kocuria sp.) were the most efficient heavy PAH degraders under electrokinetic conditions. They were re-inoculated into a polluted soil from an industrial site with a PAH concentration of 184.95 mg kg(-1). Compared to the experiments without an electric field, the degradation capability of Pseudomonas fluorescens and Kocuria sp. was enhanced in the industrially polluted soil under electrokinetic conditions. The degradation extents of total PAHs were increased by 15.4 and 14.0% in the electrokinetic PB4 and FB6 experiments (PB4 + EK and FB6 + EK) relative to the PB4 and FB6 experiments without electrokinetic conditions (PB4 and FB6), respectively. These results indicated that P. fluorescens and Kocuria sp. could efficiently degrade heavy PAHs under electrokinetic conditions and have the potential to be used for the electro-bioremediation of PAH-contaminated soil, especially if the soil is contaminated with heavy PAHs.

  10. Heavy metal displacement in chelate-irrigated soil during phytoremediation

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

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

  11. Spatial pattern of heavy metals accumulation risk in urban soils of Beijing and its influencing factors.

    PubMed

    Liu, Rui; Wang, Meie; Chen, Weiping; Peng, Chi

    2016-03-01

    Accumulations of heavy metals in urban soils are highly spatial heterogeneity and affected by multiple factors including soil properties, land use and pattern, population and climatic conditions. We studied accumulation risks of Cd, Cu, Pb and Zn in unban soils of Beijing and their influencing based on the regression tree analysis and a GIS-based overlay model. Result shows that Zinc causes the most extensive soil pollution and Cu result in the most acute soil pollution. The soil's organic carbon content and CEC and population growth are the most significant factors affecting heavy metal accumulation. Other influence factors in land use pattern, urban landscape, and wind speed also contributed, but less pronounced. The soils in areas with higher degree of urbanization and surrounded by intense vehicular traffics have higher accumulation risk of Cd, Cu, Pb, and Zn. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Taking nature into lab: biomineralization by heavy metal resistant streptomycetes in soil

    NASA Astrophysics Data System (ADS)

    Schütze, E.; Weist, A.; Klose, M.; Wach, T.; Schumann, M.; Nietzsche, S.; Merten, D.; Baumert, J.; Majzlan, J.; Kothe, E.

    2013-02-01

    Biomineralization by heavy metal resistant streptomycetes was tested to evaluate the potential influence on metal mobilities in soil. Thus, we designed an experiment adopting conditions from classical laboratory methods to natural conditions prevailing in metal-rich soils with media spiked with heavy metals, soil agar, and nutrient enriched or unamended soil incubated with the bacteria. As a result, all strains were able to form struvite minerals on tryptic soy broth (TSB) media supplemented with AlCl2, MnCl2 and CuSO4, as well as on soil agar. Some strains additionally formed struvite on nutrient enriched contaminated and control soil, as well as on metal contaminated soil without addition of media components. In contrast, switzerite was exclusively formed on minimal media spiked with MnCl2 by four heavy metal resistant strains, and on nutrient enriched control soil by one strain. Hydrated nickel hydrogen phosphate was only crystallized on complex media supplemented with NiSO4 by most strains. Thus, mineralization is a~dominant property of streptomycetes, with different processes likely to occur under laboratory conditions and sub-natural to natural conditions. This new understanding may be transferred to formation of minerals in rock and sediment evolution, to ore deposit formation, and also might have implications for our understanding of biological metal resistance mechanisms. We assume that biogeochemical cycles, nutrient storage and metal resistance might be affected by formation and re-solubilization of minerals like struvite in soil at microscale.

  13. Ultrasonic and mechanical soil washing processes for the removal of heavy metals from soils.

    PubMed

    Park, Beomguk; Son, Younggyu

    2017-03-01

    In order to determine the optimal operating conditions of full-scale soil washing processes for the removal of heavy metals, the effect of high-power ultrasound on the conventional mechanical soil washing process was investigated in a large lab-scale 28kHz sonoreactor. The soil samples were obtained from an abandoned railway station site in Seoul, Korea, which was contaminated with Cu (242.7±40.0mg/kg), Pb (441.3±49.8mg/kg), and Zn (358.0±35.7mg/kg). The treated concentrations of three heavy metal species in each process were compared with the regulation levels. It was found that higher performance, satisfying the regulation levels, was obtained in the ultrasonic/mechanical process due to the combined effects of macroscale mixing and microscale sonophysical effects. Moreover ultrasound played a more important role in less favorable conditions for the mechanical washing process (less acidic or less washing liquid conditions). Considering the application of the ultrasonic/mechanical soil washing process in real contaminated sites, the optimal conditions for the reactor with the bottom area of 15×15cm(2) and the input ultrasound power of 250W were determined as follows: (1) the amount of soil per an operation was a 300g; (2) the ratio of soil and liquid was 1:3; (3) the concentration of acidic washing liquid was 0.5M HCl. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Accumulation of heavy metals in oil-contaminated peat soils

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Savichev, A. T.; Trofimov, S. Ya.; Shishkonakova, E. A.

    2012-10-01

    X-ray fluorescence and X-ray radiometry represent easy and simple methods to determine concentrations of heavy metals in the ash of peat soils contaminated with oil and can be applied for soil monitoring purposes. Oil spills on peat bogs produce two contamination zones differing in the composition of heavy metals. In the zone of primary contamination, the peat surface is covered by a bitumen crust with V, Ni, Sr, Ba, Ce, and La accumulating there. This zone adjoins the zone of secondary peat contamination, where heavy alkaline-earth metals (Sr, Ba) and lanthanides (Ce and La) are accumulated to a lesser extent. Biological preparations recommended for remediation of oil-contaminated peat soils should be tolerant to high concentrations of heavy metals, particularly, V, Ni, and Ba that are present in the oil contaminated soils in relatively high amounts.

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

    PubMed

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

    2016-07-28

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

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

    PubMed

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

    2017-04-26

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

  17. USING BIOPOLYMERS TO REMOVE HEAVY METALS FROM SOIL AND WATER

    EPA Science Inventory

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy me...

  18. USING BIOPOLYMERS TO REMOVE HEAVY METALS FROM SOIL AND WATER

    EPA Science Inventory

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy me...

  19. Using biopolymers to remove heavy metals from soil and water

    SciTech Connect

    Krishnamurthy, S.; Frederick, R.M.

    1993-11-19

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy metals. The biopolymers discussed are chitin and chitosan, modified starch, cellulose, and polymer-containing algae. (Copyright (c) Remediation 1994.)

  20. The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

    PubMed

    Grobelak, Anna; Napora, Anna

    2015-01-01

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

  1. The Chemophytostabilisation Process of Heavy Metal Polluted Soil

    PubMed Central

    Grobelak, Anna; Napora, Anna

    2015-01-01

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

  2. Heavy metals in urban soils of East St. Louis, IL, Part I: Total concentration of heavy metals in soils.

    PubMed

    Kaminski, M D; Landsberger, S

    2000-09-01

    The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produce organic and inorganic chemicals, and petroleum refineries. A protocol for soil analysis was developed to produce sufficient information on the extent of heavy metal contamination in East St. Louis soils. Soil cores representing every borough of East St. Louis were analyzed for heavy metals--As, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Sn, and Zn. The topsoil contained heavy metal concentrations as high as 12.5 ppm Cd, 14,400 ppm Cu, ppm quantities of Hg, 1860 ppm Pb, 40 ppm Sb, 1130 ppm Sn, and 10,360 ppm Zn. Concentrations of Sb, Cu, and Cd were well correlated with Zn concentrations, suggesting a similar primary industrial source. In a sandy loam soil from a vacated rail depot near the bank of the Mississippi River, the metals were evenly distributed down to a 38-cm depth. The clay soils within a half-mile downwind of the Zn smelter and Cu products company contained elevated Cd (81 ppm), Cu (340 ppm), Pb (700 ppm), and Zn (6000 ppm) and displayed a systematic drop in concentration of these metals with depth. This study demonstrates the often high concentration of heavy metals heterogeneously distributed in the soil and provides baseline data for continuing studies of heavy metal soil leachability.

  3. Heavy metals in soils of the Russian North

    NASA Astrophysics Data System (ADS)

    Alexander, Evseev; Tatiana, Krasovskaya

    2014-05-01

    Results of soil cover studies in different regions of the Russian North from the Kola peninsula at the West and the Chuckchi peninsula at the East are presented. Heavy metals distribution in soils of both impact (technogenically disturbed) and background regions were studied. It was demonstrated that microelement soil content is closely connected with that of parent rocks which differ in different regions of the Arctic. Noticeable increase of heavy metals in the upper soil horizons are marked near large industrial sites, sometime exceeding background for more than 10-100 times. Each region and soil type has its own background concentration level. That is why no general subregional background concentration patterns may be revealed based on numerous soils sampling in different regions of the discussed territory.

  4. Enrichment of marsh soils with heavy metals by effect of anthropic pollution.

    PubMed

    Vega, Flora A; Covelo, Emma F; Cerqueira, Beatriz; Andrade, María Luisa

    2009-10-30

    The impact of waste disposal on marsh soils was assessed in topsoil samples collected at eight randomly selected points in the salt marsh in Ramallosa (Pontevedra, Spain) at 4-month intervals for 2 years. Polluted soil samples were characterized in physico-chemical terms and their heavy metal contents determined by comparison with control, unpolluted samples. The results revealed a marked effect of waste discharges on the soils in the area, which have low contents in heavy metals under normal environmental conditions. In fact, the studied soils were found to contain substantial amounts of total and DTPA-extractable Cd, Cu, Pb and Zn. Based on the relationship of the redox potential with the DTPA-extractable Cd, Cu, Pb, and Zn contents of the soils, strongly reductive conditions raised the total contents in these elements by effect of their remaining in the soils as precipitated sulphides. Such contents, however, decreased as oxidative conditions gradually prevailed. The contents in DTPA-extractable metals increased with increasing Eh through the release of the metals in ionic form to the soil solution under oxidative conditions. The contents in heavy metals concentrating in the polluted soils were several times higher than those in the control soils (viz. 2 vs. 6 for Cd, 4 vs. 6 for Cu, 4 vs. 20 for Pb, and 2 vs. 15 for Zn, all in mgkg(-1)). This can be expected to influence the amounts of available heavy metals present in the soils, and hence the environmental quality of the area, in the near future. Based on its geoaccumulation index (Class >/=3 for Cd and Cu, and 1-4 for Pb and Zn), the Ramallosa marsh is highly polluted with Cd and moderately to highly polluted with Cu, Pb and Zn. The enrichment factors obtained confirm that the salt marsh is highly polluted (especially with Cd) as the primary result of anthropic activity.

  5. An invisible soil acidification: Critical role of soil carbonate and its impact on heavy metal bioavailability

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Li, Wei; Yang, Zhongfang; Chen, Yang; Shao, Wenjing; Ji, Junfeng

    2015-07-01

    It is well known that carbonates inhibit heavy metals transferring from soil to plants, yet the mechanism is poorly understood. Based on the Yangtze River delta area, we investigated bioaccumulation of Ni and Cd in winter wheat as affected by the presence of carbonates in soil. This study aimed to determine the mechanism through which soil carbonates restrict transport and plant uptake of heavy metals in the wheat cropping system. The results indicate that soil carbonates critically influenced heavy metal transfer from soil to plants and presented a tipping point. Wheat grains harvested from carbonates-depleted (due to severe leaching) soils showed Ni and Cd concentrations 2-3 times higher than those of the wheat grains from carbonates-containing soils. Correspondingly, the incidence of Ni or Cd contamination in the wheat grain samples increased by about three times. With the carbonate concentration >1% in soil, uptake and bioaccumulation of Ni and Cd by winter wheat was independent with the soil pH and carbonate content. The findings suggest that soil carbonates play a critical role in heavy metal transfer from soil to plants, implying that monitoring soil carbonate may be necessary in addition to soil pH for the evaluating soil quality and food safety.

  6. An invisible soil acidification: Critical role of soil carbonate and its impact on heavy metal bioavailability

    PubMed Central

    Wang, Cheng; Li, Wei; Yang, Zhongfang; Chen, Yang; Shao, Wenjing; Ji, Junfeng

    2015-01-01

    It is well known that carbonates inhibit heavy metals transferring from soil to plants, yet the mechanism is poorly understood. Based on the Yangtze River delta area, we investigated bioaccumulation of Ni and Cd in winter wheat as affected by the presence of carbonates in soil. This study aimed to determine the mechanism through which soil carbonates restrict transport and plant uptake of heavy metals in the wheat cropping system. The results indicate that soil carbonates critically influenced heavy metal transfer from soil to plants and presented a tipping point. Wheat grains harvested from carbonates-depleted (due to severe leaching) soils showed Ni and Cd concentrations 2–3 times higher than those of the wheat grains from carbonates-containing soils. Correspondingly, the incidence of Ni or Cd contamination in the wheat grain samples increased by about three times. With the carbonate concentration >1% in soil, uptake and bioaccumulation of Ni and Cd by winter wheat was independent with the soil pH and carbonate content. The findings suggest that soil carbonates play a critical role in heavy metal transfer from soil to plants, implying that monitoring soil carbonate may be necessary in addition to soil pH for the evaluating soil quality and food safety. PMID:26227091

  7. An invisible soil acidification: Critical role of soil carbonate and its impact on heavy metal bioavailability.

    PubMed

    Wang, Cheng; Li, Wei; Yang, Zhongfang; Chen, Yang; Shao, Wenjing; Ji, Junfeng

    2015-07-31

    It is well known that carbonates inhibit heavy metals transferring from soil to plants, yet the mechanism is poorly understood. Based on the Yangtze River delta area, we investigated bioaccumulation of Ni and Cd in winter wheat as affected by the presence of carbonates in soil. This study aimed to determine the mechanism through which soil carbonates restrict transport and plant uptake of heavy metals in the wheat cropping system. The results indicate that soil carbonates critically influenced heavy metal transfer from soil to plants and presented a tipping point. Wheat grains harvested from carbonates-depleted (due to severe leaching) soils showed Ni and Cd concentrations 2-3 times higher than those of the wheat grains from carbonates-containing soils. Correspondingly, the incidence of Ni or Cd contamination in the wheat grain samples increased by about three times. With the carbonate concentration >1% in soil, uptake and bioaccumulation of Ni and Cd by winter wheat was independent with the soil pH and carbonate content. The findings suggest that soil carbonates play a critical role in heavy metal transfer from soil to plants, implying that monitoring soil carbonate may be necessary in addition to soil pH for the evaluating soil quality and food safety.

  8. Competitive sorption and desorption of heavy metals in mine soils: influence of mine soil characteristics.

    PubMed

    Vega, F A; Covelo, E F; Andrade, M L

    2006-06-15

    Many mine soils are chemically, physically, and biologically unstable and deficient. They are sometimes amended with sewage sludge and ashes but often contain heavy metals that increase the already high mine soils' heavy metal contents. Cd, Cr, Cu, Ni, Pb, and Zn in mutual competition were added to five mine soils (Galicia, Spain). Soil capacities for heavy metal sorption and retention were determined by means of distribution coefficients and selectivity sequences among metals. Influence of soil characteristics on sorption and retention was also examined. Retention selectivity sequences indicate that, in most of the soils, Pb is the preferred retained metal, followed by Cr. The last metals in these sequences are Ni, Cd, and Zn. Soil organic matter content plays a fundamental role in control of Pb sorption. Gibbsite, goethite, and mica influence Cr retention. Soil organic matter, oxides, and chlorite contents are correlated with K(d sigma sp medium). Heavy metals are weakly adsorbed by soils and then desorbed in high amounts. To recover these soils it is necessary to avoid the use of residues or ashes that contain heavy metals due to their low heavy metal retention capacity.

  9. Ecological risk assessment of soil pollution with heavy metals

    SciTech Connect

    Kuperman, R.G.

    1995-12-31

    The structure and function of soil ecosystems in an area with a wide range of concentrations of heavy metals were studied in portions of the US Army`s Aberdeen Proving Ground, Maryland. The objective of this project was to develop and test the efficacy of a comprehensive methodology for assessing ecological impacts of soil contamination. A hierarchical approach which integrated biotic parameters and ecosystem processes was used to give insight into the mechanisms that lead to alterations in the structure and function of soil ecosystems in contaminated areas. This approach involved (1) a thorough survey of the soil biota to establish community structure, (2) laboratory and field tests on critical ecosystem processes, (3) toxicity trials, and (4) the use of spatial analyses to provide input in the decision making process. Soil invertebrate communities showed significant reductions in the abundance of several taxonomic and trophic groups in contaminated areas. The numbers of soil microorganisms were lower in areas of soil contamination. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area. The proposed methodology appears to offer an efficient and potentially cost saving tool for remedial investigations at contaminated sites.

  10. Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil.

    PubMed

    Lambrechts, Thomas; Gustot, Quentin; Couder, Eléonore; Houben, David; Iserentant, Anne; Lutts, Stanley

    2011-11-01

    Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm(3)-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg(-1) of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl(2) extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.

  11. Simulation of Soil Water Content Variability in a Heavy Clay Soil under Contrasting Soil Managements

    NASA Astrophysics Data System (ADS)

    Pedrera, A.; Vanderlinden, K.; Martínez, G.; Espejo, A. J.; Giráldez, J. V.

    2012-04-01

    Soil water content (SWC) is a key variable for numerous physical, chemical and biological processes that take place at or near the soil surface. Understanding the spatial and temporal variability of SWC at the field scale is of prime importance for implementing efficient measurement strategies in applications. The aim of this study was to characterize the spatial and temporal variation of gravimetric SWC in a heavy clay soil, in a wheat-sunflower-legume rotation under conventional (CT) and no-till (NT) using a simple water balance model. An experimental field in SW Spain, where conventional (CT) and no-till (NT) management of a heavy clay soil are being compared since 1983, was sampled for gravimetric SWC on 38 occasions during 2008 and 2009. Topsoil clay content across the six plots was on average 55%, with a standard deviation of 2.7%. The soil profile was sampled at 54 locations, evenly distributed over the three CT and NT plots, at depths of 0-10, 25-35, and 55-65 cm. Topsoil water retention curves (SWRC) were determined in the laboratory on undisturbed soil samples from each of the 54 locations. A weather station recorded daily precipitation and evapotranspiration, as calculated by the Penman-Monteith FAO equation. The water balance was calculated using the Thornthwaite-Mather model with a daily time step. Three parameters, water holding capacity, and water evaporation corrector coefficients for each of the two years, were inversely estimated at the 54 SWC observation points and probability density functions were identified. Spatial variability of SWC was estimated using a Monte Carlo approach, and simulated and observed variability were compared. This Monte Carlo scheme, using a simple water balance model with only three parameters, was found to be useful for evaluating the influence of soil management on the variability of SWC in heavy clay soils.

  12. Heavy metals in garden soils along roads in Szeged, Hungary

    NASA Astrophysics Data System (ADS)

    Szolnoki, Zsuzsanna; Farsang, Andrea

    2010-05-01

    The soils of the urban environment, owing to the various anthropogenic activities, can be contaminated by heavy metals. The traffic is well-known for more decades to be main source of heavy metals mostly in cities. The accumulation of these elements can have different effects, either directly endangering the natural soil functions, or indirectly endangering the biosphere by bio-accumulation and inclusion in the food chain. The hobby gardens and the vegetable gardens directly along roads can be potential risky for people since unknown amount of heavy metals can be accumulated into organization of local residents due to consumption of vegetables and fruits grown in their own garden. The aim of this study was to determine the heavy metal content of garden soils directly along roads with heavy traffic in order to assess possible risk for human health. The total content and the mobile content of Cd, Co, Cr, Cu, Ni, Pb and Zn have been determined in samples from garden soils along 5 busy roads of Szeged, South Hungary. Enrichment factor has been calculated with the help of control soil samples far from roads. The soil properties basically influencing on metal mobility have also been examined. Finally, the human health risk of these garden soils has been modelled by determination of health risk quotient (HRQ). As a result of our investigations, it can be claimed that mostly Cu, Zn and to a lesser degree the Ni, Cr and Pb accumulated in garden soils along roads depending on the traffic density. In general, the topsoils (0-10 cm) had higher amount of these metals rather than the subsoils (40-50 cm). Ni of these metals has approached; Cu has exceeded limit value while Pb is under it. Cd is very high in both soils along roads and control ones far from roads. Garden soils along the roads have such basic soil parameters (pH, mechanical soil type, humus content) that prove fairly high metal-binding capacity for these soils. Total risk of usage of these gardens (ingestion of soil

  13. Ultrasonically aided mineral processing technique for remediation of soil contaminated by heavy metals.

    PubMed

    Kyllönen, Hanna; Pirkonen, Pentti; Hintikka, Väinö; Parvinen, Pekka; Grönroos, Antti; Sekki, Hannu

    2004-05-01

    In this study, power ultrasound was used as aiding method for the mineral processing technique, which have recently been developed for the remediation of soil contaminated by heavy metal containing bullets, their broken parts and alteration products. Power ultrasound was used to disperse the soil to remove metals and metal compounds from soil particle surfaces instead of attrition conditioning. The soil diluted with water was treated using 22 kHz ultrasound power of 100 W up to 500 W. The effect of different ultrasonic treatment time and pulsation of ultrasound were studied on the purity of sink and float fractions in heavy medium separation process, screen fractions, and mineral concentrates and tailings from flotation process. Ultrasound enhanced the remediation of soil fractions in all the studied cases. Optimisation of the ultrasonic power will be done in the continuation study.

  14. [Influence of Dissimilatory Iron Reduction on the Speciation and Bioavailability of Heavy Metals in Soil].

    PubMed

    Si, You-bin; Wang, Juan

    2015-09-01

    Fe(III) dissimilatory reduction by microbes is an important process of producing energy in the oxidation of organic compounds under anaerobic condition with Fe(III) as the terminal electron acceptor and Fe(II) as the reduction product. This process is of great significance in element biogeochemical cycle. Iron respiration has been described as one of the most ancient forms of microbial metabolism on the earth, which is bound up with material cycle in water, soil and sediments. Dissimilatory iron reduction plays important roles in heavy metal form transformation and the remediation of heavy metal and radionuclide contaminated soils. In this paper, we summarized the research progress of iron reduction in the natural environment, and discussed the influence and the mechanism of dissimilatory iron reduction on the speciation and bioavailability of heavy metals in soil. The effects of dissimilatory iron reduction on the speciation of heavy metals may be attributed to oxidation and reduction, methytation and immobilization of heavy metals in relation to their bioavailability in soils. The mechanisms of Fe(III) dissimilatory reduction on heavy metal form transformation contain biological and chemical interactions, but the mode of interaction remains to be further investigated.

  15. Molecular Indicators of Soil Humification and Interaction with Heavy Metals

    SciTech Connect

    Fan, Teresa W.-M.; Higashi, Richard M.; Cassel, Teresa; Green, Peter; Lane, Andrew N.

    2003-03-26

    For stabilization of heavy metals at contaminated sites, interaction of soil organic matter (SOM) with heavy metal ions is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using 13C- and 15N-labeled soil humates (HS), we investigated the turnover of five organic amendments (celluose, wheat straw, pine shavings, chitin and bone meal) in relation to heavy metal ion leaching in soil column experiments. The labeled molecular substructures in HS were examined by multinuclear 2-D NMR and pyrolysis GC-MS while the element profile in the leachates was analyzed by ICP-MS. Preliminary analysis revealed that peptidic and polysaccharidic structures were highly enriched, which suggests their microbial origin. Cd(II) leaching was significantly attenuated with humification of lignocellulosic materials. Correlation of 13C and 15N turnovers of HS substructures to metal leaching is underway.

  16. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  17. Pollution evaluation of heavy metals in soil near smelting area by index of geoaccumulation (Igeo)

    NASA Astrophysics Data System (ADS)

    Huang, S. H.; Yang, Y.; Yuan, C. Y.; Li, Q.; Ouyang, K.; Wang, B.; Wang, Z. X.

    2017-01-01

    In order to investigate the heavy metal pollution conditions of soil of smelting area in Zijiang of Chenzhou, Hunan province, 42 samples were studied. The concentrations of heavy metals As, Pb, Cd, Zn and Cu in the soil were determined by using atomic absorption spectrometry(AAS) and atomic fluorescence spectrometry(AFS). Then the potential pollution risks of heavy metal in the soil were evaluated by method of geological acumination index (Igeo). The results indicated that the average concentrations of As, Pb, Cd, Zn and Cu were 187.79, 2074.52, 15.72, 2178.89, 39.69 mg/kg respectively. The geological evaluation of the cumulative index results showed that the contamination degree of 5 heavy metals follow the sequence of Cd> Zn >Pb > As >Cu. The results show that Cd reached extremely pollution degree, Zn reached strong pollution-extremely pollution levels, the pollution of Pb in the soil is classified as strong pollution degree, Cu and As of no pollution according to the results of Igeo based on the background value of heavy metals in the soil of Hunan Province.

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

    PubMed

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

    2011-11-30

    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 100mg/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.

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

    PubMed

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2013-10-01

    This study describes the potential application of lipopeptide biosurfactants in removal of petroleum hydrocarbons and heavy metals from the soil samples collected from industrial dumping site. High concentrations of heavy metals (like iron, lead, nickel, cadmium, copper, cobalt and zinc) and petroleum hydrocarbons were present in the contaminated soil samples. Lipopeptide biosurfactant, consisting of surfactin and fengycin was obtained from Bacillus subtilis A21. Soil washing with biosurfactant solution removed significant amount of petroleum hydrocarbon (64.5 %) and metals namely cadmium (44.2 %), cobalt (35.4 %), lead (40.3 %), nickel (32.2 %), copper (26.2 %) and zinc (32.07 %). Parameters like surfactant concentration, temperature, agitation condition and pH of the washing solution influenced the pollutant removing ability of biosurfactant mixture. Biosurfactant exhibited substantial hydrocarbon solubility above its critical micelle concentration. During washing, 50 % of biosurfactant was sorbed to the soil particles decreasing effective concentration during washing process. Biosurfactant washed soil exhibited 100 % mustard seed germination contradictory to water washed soil where no germination was observed. The results indicate that the soil washing with mixture of lipopeptide biosurfactants at concentrations above its critical micelle concentration can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil.

  20. Assessment of heavy metals contamination and leaching characteristics in highway side soils, Iran.

    PubMed

    Saeedi, Mohsen; Hosseinzadeh, Majid; Jamshidi, Ahmand; Pajooheshfar, S P

    2009-04-01

    Twenty seven topsoil samples were collected under stable weather conditions from the northern and southern sides of Tehran-Karaj Highway, Iran. Samples were analyzed for heavy metal (Pb, V, Zn, Ni, Co, Cr, Cd, and Mn) contents and leaching characteristics. The results showed that all heavy metal contents except Cr, Mn and Co are higher than acceptable values in natural soils. High contents of these elements could be attributed to anthropogenic effects related to traffic sources. Toxicity characteristics leaching procedure (TCLP) test results reveal that the studied soils may be hazardous. Statistical analysis shows significant positive correlations between heavy metals and organic matter. Also a significant correlation was observed between Cd, Pb and Zn. This affinity and exponentially decreasing concentration with distance from the edge of the road suggest that automobiles are a major source of these metals in the roadside soils. Use of leaded gasoline and tire erosion gives a boost to this claim.

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

    PubMed

    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.

  2. Effect of humic acid on transformation of soil heavy metals

    NASA Astrophysics Data System (ADS)

    Wu, Shengzhe; Li, Rui; Peng, Shuyang; Liu, Qiuyong; Zhu, Xi

    2017-06-01

    The pattern of transformation among different fractions of heavy metals in soil draws great attention. This article investigated the effect of humic acid on soil heavy metal under different pH and temperature. The results showed that with the increasing of the concentration of humic acid, the concentration of available Cu, Pb decreased greatly, though the decrease of available Cd was light. Also, pH of soil had certain impact on the concentration of available Cu, Pb, Cd while the influence of environmental temperature was minor. The removal efficiency of contaminated soil was 57.283% (Cu), 2.645% (Cd) and 15.485% (Pb) while it could reach more than 98% in contaminated solution.

  3. Soil remediation demonstration project: Biodegradation of heavy fuel oils. Special report

    SciTech Connect

    Reynolds, C.M.; Bhunia, P.; Koenen, B.A.

    1997-08-01

    Treatment of oil-contaminated soils is necessary to protect water supplies, human health, and environmental quality; but because of limited funds, cleanup costs are often prohibitive. High costs are exacerbated in cold regions such as Alaska, where spills are often in areas inaccessible to heavy equipment and where there is limited infrastructure. Owing to the lack of infrastructure, widespread fuel distribution systems, and the need for heating in the cold climate, there are numerous small-scale oil spills. Low-cost treatments applicable to small-scale spills are needed. The object of this CPAR project was to examine using cost-effective, on-site bioremediation techniques for heavy-oil-contaminated soil in cold regions. Both heavy-oil and diesel-contaminated soils were used to compare landfarming, a low-intensity treatment, to pile bioventing, a costlier treatment. For each soil-contaminant combination, we compared nutrient additions to a control with no nutrient additions. Under the conditions of this study, landfarming with nutrient additions was as effective for treating diesel-contaminated soil as was bioventing with nutrient additions. For heavy oils, landfarming with nutrients resulted in lower soil concentrations after one year, but differences among treatments were not statistically significant. Because landfarming does not require pumps, electricity, or plumbing, all costs are less than for bioventing. The minimal requirements for infrastructure also make landfarming attractive in remote sites typical of cold regions.

  4. [Distribution of Urban Soil Heavy Metal and Pollution Evaluation in Different Functional Zones of Yinchuan City].

    PubMed

    Wang, You-qi; Bai, Yi-ru; Wang, Jian-yu

    2016-02-15

    Surface soil samples (0-20 cm) from eight different functional areas in Yinchuan city were collected. There were 10 samples respectively in each functional area. The urban soil heavy metals (Zn, Cd, Pb, Mn, Cu and Cr) pollution characteristics and sources in eight different functional areas were evaluated by mathematical statistics and geostatistical analysis method. Meanwhile, the spatial distributions of heavy metals based on the geography information system (GIS) were plotted. The average values of total Zn, Cd, Pb, Mn, Cu and Cr were 74.87, 0.15, 29.02, 553.55, 40.37 and 80.79 mg x kg(-1), respectively. The results showed that the average value of soil heavy metals was higher than the soil background value of Ningxia, which indicated accumulation of the heavy metals in urban soil. The single factor pollution index of soil heavy metals was in the sequence of Cu > Pb > Zn > Cr > Cd > Mn. The average values of total Zn, Cd, Pb and Cr were higher in north east, south west and central city, while the average values of Mn and Cu were higher in north east and central city. There was moderate pollution in road and industrial area of Yinchuan, while the other functional areas showed slight pollution according to Nemoro synthesis index. The pollution degree of different functional areas was as follows: road > industrial area > business district > medical treatment area > residential area > public park > development zone > science and education area. The results indicated that the soil heavy metal pollution condition in Yinchuan City has been affected by human activities with the development of economy.

  5. [Heavy Metals Accmultio in the Caofeidian Reclamation Soils: Indicated by Soil Magnetic Susceptibility].

    PubMed

    Xue, Yong; Zhou, Qian; Li, Yuan; Zhang, Hai-bo; Hu, Xue-feng; Luo, Yong-ming

    2016-04-15

    The environmental magnetism method has been widely applied to identify soil heavy metal pollution, which is characterized by simplicity, efficiency, non-destructivity and sensitivity. The present study used magnetic susceptibility to assess the accumulation of heavy metals in soils of the Caofeidian industrial zone which is a typical reclamation area in northern China. The study area was divided into three sub-zones based on the function, including industrial zone, living zone, natural tidal flat and wetland. A total of 35 topsoil samples (0-10 cm) and 3 soil profiles were collected from the three sub-zones. Magnetic susceptibility (X(lf)), iron oxide (Fe2O3) contents and heavy metals contents (Cr, Ni, Cu, Zn, As, Pb, Mn and V) of the samples were analyzed. The results showed that X(lf) values and heavy metals contents exhibited higher spatial variability in the top soil of the industrial zone, indicating the severe impacts of industrial activities. In the soil profiles of the industrial and living zones, all heavy metals were enriched to different degrees in the upper layer (0-20 cm). However, there was no significant change of heavy metal contents in the soil profiles of tidal flat which was far from the industrial area. The X(lf) value was significantly (P < 0.01) positively correlated with the contents of Fe2O3, Ni, Cu, As and V in the industrial top soil. This indicated that X(lf) could be used as an indicator for heavy metal accumulation in the industrial zone. However, the X(lf) value was not suitable to be an indicator to show the heavy metal accumulation in the soils of living zone and natural tidal flat. This might be associated with the different sources of magnetic materials among the different sub-zones and the special characteristics of the soils in the tidal flat and wetland.

  6. 24 CFR 3285.201 - Soil conditions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Soil conditions. 3285.201 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.201 Soil conditions. To help prevent settling or sagging, the foundation must be constructed on firm, undisturbed soil or...

  7. 24 CFR 3285.201 - Soil conditions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Soil conditions. 3285.201 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.201 Soil conditions. To help prevent settling or sagging, the foundation must be constructed on firm, undisturbed soil or...

  8. 24 CFR 3285.201 - Soil conditions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Soil conditions. 3285.201 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.201 Soil conditions. To help prevent settling or sagging, the foundation must be constructed on firm, undisturbed soil or...

  9. 24 CFR 3285.201 - Soil conditions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Soil conditions. 3285.201 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.201 Soil conditions. To help prevent settling or sagging, the foundation must be constructed on firm, undisturbed soil or...

  10. 24 CFR 3285.201 - Soil conditions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Soil conditions. 3285.201 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.201 Soil conditions. To help prevent settling or sagging, the foundation must be constructed on firm, undisturbed soil or...

  11. Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

    PubMed

    Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang

    2015-06-01

    There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd.

  12. Heavy Metals Phytoextraction from the Polluted Soils of Zakamensk (Russia)

    NASA Astrophysics Data System (ADS)

    Ubugunov, V.; Dorzhonova, V.; Ubugunov, L.

    2012-04-01

    the landscape - Modonkul river flood plain, were transferred by its waters and redeposited in an estuary, forming a cone of carrying out with capacity of up to 2 meters or more. The presence of large number of private houses with garden plots, in which the population grew potatoes, vegetables and fruit-berry trees cultures for food purposes, is the feature of many Siberian towns, including Zakamensk. The biogeochemical assessment of the town territory current status has shown a high level of contamination of soils and plants by heavy metals that poses a threat to the health of townsmen. In this connection search of effective ways of clearing up of the polluted soils by phytoextraction and selection of plants, capable to extract high quantities of heavy metals from soil in concrete ecological conditions, is actual. For this purpose we had been made experiments with 8 species of plants. Modeling of various conditions of pollution carried out by addition of following quantities of TS (%): 0; 25; 33; 50; 67; 75 and 100. In the report results of the experiments and the recommendations on using of plants as extractors on soils polluted by technogenic sand will be presented.

  13. Heavy Metal Contaminated Soil Treatment: Conceptual Development

    DTIC Science & Technology

    1987-02-01

    circuit without trans- ferring hear from a metallic resistance element. Contaminated soils may be accepted directly with little or (to pretreatment ...with metals has been demon-- strated. No pretreatment for organics destruction would be required. The system can also readily handle liquid wastes and...applications as a pretreatment /recovery step. J 38 0458Bi 3.7.3 Long term stability/performance. The process would remove metals from the soil. Therefore, if

  14. Taking nature into lab: biomineralization by heavy metal-resistant streptomycetes in soil

    NASA Astrophysics Data System (ADS)

    Schütze, E.; Weist, A.; Klose, M.; Wach, T.; Schumann, M.; Nietzsche, S.; Merten, D.; Baumert, J.; Majzlan, J.; Kothe, E.

    2013-06-01

    Biomineralization by heavy metal-resistant streptomycetes was tested to evaluate the potential influence on metal mobilities in soil. Thus, we designed an experiment adopting conditions from classical laboratory methods to natural conditions prevailing in metal-rich soils with media spiked with heavy metals, soil agar, and nutrient-enriched or unamended soil incubated with the bacteria. As a result, all strains were able to form struvite minerals (MgNH4PO4• 6H2O) on tryptic soy broth (TSB)-media supplemented with AlCl3, MnCl2 and CuSO4, as well as on soil agar. Some strains additionally formed struvite on nutrient-enriched contaminated and control soil, as well as on metal contaminated soil without addition of media components. In contrast, switzerite (Mn3(PO4)2• 7H2O) was exclusively formed on minimal media spiked with MnCl2 by four heavy metal-resistant strains, and on nutrient-enriched control soil by one strain. Hydrated nickel hydrogen phosphate was only crystallized on complex media supplemented with NiSO4 by most strains. Thus, mineralization is a dominant property of streptomycetes, with different processes likely to occur under laboratory conditions and sub-natural to natural conditions. This new understanding might have implications for our understanding of biological metal resistance mechanisms. We assume that biogeochemical cycles, nutrient storage and metal resistance might be affected by formation and re-solubilization of minerals like struvite in soil at microscale.

  15. Methane oxidation in heavy metal contaminated Mollic Gleysol under oxic and hypoxic conditions.

    PubMed

    Walkiewicz, A; Bulak, P; Brzezińska, M; Wnuk, E; Bieganowski, A

    2016-06-01

    Soils are the largest terrestrial sink for methane (CH4). However, heavy metals may exert toxicity to soil microorganisms, including methanotrophic bacteria. We tested the effect of lead (Pb), zinc (Zn) and nickel (Ni) on CH4 oxidation (1% v/v) and dehydrogenase activity, an index of the activity of the total soil microbial community in Mollic Gleysol soil in oxic and hypoxic conditions (oxia and hypoxia, 20% and 10% v/v O2, respectively). Metals were added in doses corresponding to the amounts permitted of Pb, Zn, Ni in agricultural soils (60, 120, 35 mg kg(-1), respectively), and half and double of these doses. Relatively low metal contents and O2 status reflect the conditions of most agricultural soils of temperate regions. Methane consumption showed high tolerance to heavy metals. The effect of O2 status was stronger than that of metals. CH4 consumption was enhanced under hypoxia, where both the start and the completion of the control and contaminated treatment were faster than under oxic conditions. Dehydrogenase activity, showed higher sensitivity to the contamination (except for low Ni dose), with a stronger effect of heavy metals, than that of the O2 status. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Technical development of geomicrobiological fixation of heavy metals in soils and sediments by biosorption and bioreduction -case histories in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Eun; Kim, Sang-Ho; Lee, Jong-Un; Chon, Hyo-Taek

    2013-04-01

    Conventional physicochemical technologies to remediate heavy metals-contaminated soil have many problems such as low efficiency, high cost and occurrence of byproducts. Recently biological stabilization technology is getting more and more attention. The advantage of this technology is that toxic metals can be stabilized for long time with no necessity of retreatment. The objective of this research is to develop geomicrobiological stabilization technologies of heavy metals by biosorption and oxidation/reduction in contaminated soil and sediment. Geochemical characteristics of heavy metals such as concentration and speciation in contaminated soil were investigated. Environmental conditions for effective biosorption were also investigated. It was successful to form biofilm in soil. Biofilm had great heavy metal biosorption capacity. Bioreduction efficiency of hexavalent chromium by indigenous bacteria was evaluated in various conditions.. From now on, it is necessary to prove applicability of this technologies to contaminated sites and to establish highly effective, low-cost and easy bioremediation technology.

  17. Modern approaches to remediation of heavy metal polluted soils: A review

    NASA Astrophysics Data System (ADS)

    Koptsik, G. N.

    2014-07-01

    The main principles and approaches to remediation of in situ polluted soils aimed at the removal or control of heavy metals (washing, stabilization, phytoremediation, and natural restoration) are analyzed. The prospects of gentle methods of stabilization oriented at the reduction of the mobility and biological availability of heavy metals due to the processes of adsorption, ionic exchange, and precipitation are emphasized. The use of sorbents and the traditional application of liming and phosphates to fix metal pollutants in soils is considered. The necessary conditions for successful soil remediation are the assessment of its economic efficiency, the analysis of the ecological risks, and confirming the achievement of the planned purposes related to the content of available metals in the soils.

  18. Fate of heavy metals and agrochemicals in biochar amended soils

    USDA-ARS?s Scientific Manuscript database

    Heavy metals and agrochemicals are the key targets for biochar-induced mitigation of runoff/groundwater contamination. Inorganic and organic contaminants interact differently with biochars as well as soil components. Mechanistic understandings are needed on sorption, desorption, and competitive sor...

  19. Agro-improving method of phytoextracting heavy metal contaminated soil.

    PubMed

    Wei, Shuhe; Teixeira da Silva, Jaime A; Zhou, Qixing

    2008-02-11

    Phytoextraction of heavy metal contaminated soils is a promising remediation technology. Till now, more than several hundreds of hyperaccumulators or non-hyperaccumulators which can be used to clean polluted soils with heavy metals have been reported. However, phytoextraction is still not extensively applied. Thus, some measurements should be taken to improve phytoremediation. This paper introduced the basic mechanisms of phytoextration, its main restrictive factors, its relationship with agricultural technology and some agricultural improvement methods. We suggested that unavailable heavy metal activation, crop breeding, seed-coating and felicitous utilization of fertilizer and water, as well as the use of two-phase planting may be important and indispensable paths for phytoextraction to be widely applied at a commercial level in the future.

  20. Relationship between Heavy Metal Concentrations in Soils and Grasses of Roadside Farmland in Nepal

    PubMed Central

    Yan, Xuedong; Zhang, Fan; Zeng, Chen; Zhang, Man; Devkota, Lochan Prasad; Yao, Tandong

    2012-01-01

    Transportation activities can contribute to accumulation of heavy metals in roadside soil and grass, which could potentially compromise public health and the environment if the roadways cross farmland areas. Particularly, heavy metals may enter the food chain as a result of their uptake by roadside edible grasses. This research was conducted to investigate heavy metal (Cu, Zn, Cd, and Pb) concentrations in roadside farmland soils and corresponding grasses around Kathmandu, Nepal. Four factors were considered for the experimental design, including sample type, sampling location, roadside distance, and tree protection. A total of 60 grass samples and 60 topsoil samples were collected under dry weather conditions. The Multivariate Analysis of Variance (MANOVA) results indicate that the concentrations of Cu, Zn, and Pb in the soil samples are significantly higher than those in the grass samples; the concentrations of Cu and Pb in the suburban roadside farmland are higher than those in the rural mountainous roadside farmland; and the concentrations of Cu and Zn at the sampling locations with roadside trees are significantly lower than those without tree protection. The analysis of transfer factor, which is calculated as the ratio of heavy-metal concentrations in grass to those in the corresponding soil, indicates that the uptake capabilities of heavy metals from soil to grass is in the order of Zn > Cu > Pb. Additionally, it is found that as the soils’ heavy-metal concentrations increase, the capability of heavy-metal transfer to the grass decreases, and this relationship can be characterized by an exponential regression model. PMID:23202679

  1. Influence of traffic activity on heavy metal concentrations of roadside farmland soil in mountainous areas.

    PubMed

    Zhang, Fan; Yan, Xuedong; Zeng, Chen; Zhang, Man; Shrestha, Suraj; Devkota, Lochan Prasad; Yao, Tandong

    2012-05-01

    Emission of heavy metals from traffic activities is an important pollution source to roadside farmland ecosystems. However, little previous research has been conducted to investigate heavy metal concentrations of roadside farmland soil in mountainous areas. Owing to more complex roadside environments and more intense driving conditions on mountainous highways, heavy metal accumulation and distribution patterns in farmland soil due to traffic activity could be different from those on plain highways. In this study, design factors including altitude, roadside distance, terrain, and tree protection were considered to analyze their influences on Cu, Zn, Cd, and Pb concentrations in farmland soils along a mountain highway around Kathmandu, Nepal. On average, the concentrations of Cu, Zn, Cd, and Pb at the sampling sites are lower than the tolerable levels. Correspondingly, pollution index analysis does not show serious roadside pollution owing to traffic emissions either. However, some maximum Zn, Cd, and Pb concentrations are close to or higher than the tolerable level, indicating that although average accumulations of heavy metals pose no hazard in the region, some spots with peak concentrations may be severely polluted. The correlation analysis indicates that either Cu or Cd content is found to be significantly correlated with Zn and Pb content while there is no significant correlation between Cu and Cd. The pattern can be reasonably explained by the vehicular heavy metal emission mechanisms, which proves the heavy metals' homology of the traffic pollution source. Furthermore, the independent factors show complex interaction effects on heavy metal concentrations in the mountainous roadside soil, which indicate quite a different distribution pattern from previous studies focusing on urban roadside environments. It is found that the Pb concentration in the downgrade roadside soil is significantly lower than that in the upgrade soil while the Zn concentration in the

  2. Influence of Traffic Activity on Heavy Metal Concentrations of Roadside Farmland Soil in Mountainous Areas

    PubMed Central

    Zhang, Fan; Yan, Xuedong; Zeng, Chen; Zhang, Man; Shrestha, Suraj; Devkota, Lochan Prasad; Yao, Tandong

    2012-01-01

    Emission of heavy metals from traffic activities is an important pollution source to roadside farmland ecosystems. However, little previous research has been conducted to investigate heavy metal concentrations of roadside farmland soil in mountainous areas. Owing to more complex roadside environments and more intense driving conditions on mountainous highways, heavy metal accumulation and distribution patterns in farmland soil due to traffic activity could be different from those on plain highways. In this study, design factors including altitude, roadside distance, terrain, and tree protection were considered to analyze their influences on Cu, Zn, Cd, and Pb concentrations in farmland soils along a mountain highway around Kathmandu, Nepal. On average, the concentrations of Cu, Zn, Cd, and Pb at the sampling sites are lower than the tolerable levels. Correspondingly, pollution index analysis does not show serious roadside pollution owing to traffic emissions either. However, some maximum Zn, Cd, and Pb concentrations are close to or higher than the tolerable level, indicating that although average accumulations of heavy metals pose no hazard in the region, some spots with peak concentrations may be severely polluted. The correlation analysis indicates that either Cu or Cd content is found to be significantly correlated with Zn and Pb content while there is no significant correlation between Cu and Cd. The pattern can be reasonably explained by the vehicular heavy metal emission mechanisms, which proves the heavy metals’ homology of the traffic pollution source. Furthermore, the independent factors show complex interaction effects on heavy metal concentrations in the mountainous roadside soil, which indicate quite a different distribution pattern from previous studies focusing on urban roadside environments. It is found that the Pb concentration in the downgrade roadside soil is significantly lower than that in the upgrade soil while the Zn concentration in the

  3. Soil heavy metal dynamics and risk assessment under long-term land use and cultivation conversion.

    PubMed

    Wang, Xuelei; Xu, Yiming

    2015-01-01

    Long-term agricultural development and cultivation conversions affect soil heavy metal balance and the regional environmental safety. In this study, heavy metal parameters were used to identify changes in soil properties in response to land use and cultivation conversions. The integrated soil quality index, which involves seven heavy metal indices, was proposed to assess the environmental risk of long-term human activities in Northeast China. We used the remote sensing and geographical data for the four-term land use distribution from 1979 to 2009 to identify the spatial patterns of regional land use conversions. Then, 41 samples from the top 20 cm of the soil at sites corresponding to these seven types of conversions were collected (permanent dry land, dry land converted from wetland, dry land converted from forest, permanent wetland, permanent forest, paddy land converted from dry land, and paddy land converted from wetland). Based on the local soil properties and tillage practices, the following seven heavy metal parameters were employed: Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), and Zinc (Zn). The conversion of farmland from wetland resulted in an increase in the concentration of Pb and Cr in the soil. In contrast, the concentrations of Zn, Cu, Ni, and Cd decreased when wetland was converted into farmland because the tillage practices washed these heavy metals away. During the conversion of dry land and paddy land to wetland, the levels of Pb increased by approximately 28.6% and 24.7%, respectively. Under the same conditions, the concentration of As increased by 32.5% and 14.1%, respectively. The integrated index also demonstrated that the farmlands were not contaminated by the heavy metals during long-term agricultural development.

  4. Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils.

    PubMed

    Dietterich, Lee H; Gonneau, Cédric; Casper, Brenda B

    2017-09-01

    The factors affecting plant uptake of heavy metals from metalliferous soils are deeply important to the remediation of polluted areas. Arbuscular mycorrhizal fungi (AMF), soil-dwelling fungi that engage in an intimate exchange of nutrients with plant roots, are thought to be involved in plant metal uptake as well. Here, we used a novel field-based approach to investigate the effects of AMF on plant metal uptake from soils in Palmerton, Pennsylvania, USA contaminated with heavy metals from a nearby zinc smelter. Previous studies often focus on one or two plant species or metals, tend to use highly artificial growing conditions and metal applications, and rarely consider metals' effects on plants and AMF together. In contrast, we examined both direct and AMF-mediated effects of soil concentrations on plant concentrations of 8-13 metals in five wild plant species sampled across a field site with continuous variation in Zn, Pb, Cd, and Cu contamination. Plant and soil metal concentration profiles were closely matched despite high variability in soil metal concentrations even at small spatial scales. However, we observed few effects of soil metals on AMF colonization, and no effects of AMF colonization on plant metal uptake. Manipulating soil chemistry or plant community composition directly may control landscape-level plant metal uptake more effectively than altering AMF communities. Plant species identities may serve as highly local indicators of soil chemical characteristics. © 2017 by the Ecological Society of America.

  5. A Linkage Between Parent Materials of Soil and Potential Risk of Heavy Metals in Yunnan province, China

    NASA Astrophysics Data System (ADS)

    Cheng, X.

    2015-12-01

    A large area exceeding soil quality standards for heavy metals in South western China has been identified previously reported on a nationwide survey of soil pollution, yet the ecological risk of heavy metal in soil is unknown or uncertainty.To assess thoroughly the ecological risk in this region, seven soil profiles with a depth of 2m on the different parent materials of soil were conducted in Yunnan province, China, and the level of total concentrations and the fraction of water soluble, ion exchangeable, carbonates, humic acid, iron and manganese oxides and organic matter of As, Cd, Hg and Pb was investigated in soil profiles. The results indicate that parent materials of soil critically influenced the ecological risk of heavy metal.The fraction of water soluble and ion exchangeable of Cd and Hg in alluvial material and in terrigenous clastic rocks showed 2-6 times higher than those in carbonate rock; As and Pb has almost same fraction of water soluble and ion exchangeable in three parent materials of soil.The findings suggest that parent materials of soil play a critical role in ecological risk of heavy metal.Thus, more studies are needed to better understand a linkage between the parent materials of soil, different soil-forming processes and the potential risk of heavy metals under various geographic conditions, which is the key for the evaluating soil quality and food safety. Those soils with high concentration of Cd and Hg originated alluvial material and terrigenous clastic rocks need to be continuously monitored before determining a cost-effective remediation technology. Keywords: Heavy metals; Ecological risk;Parent materials of soil;China

  6. Effect of fertilizer application on soil heavy metal concentration.

    PubMed

    Atafar, Zahra; Mesdaghinia, Alireza; Nouri, Jafar; Homaee, Mehdi; Yunesian, Masoud; Ahmadimoghaddam, Mehdi; Mahvi, Amir Hossein

    2010-01-01

    A large amount of chemicals is annually applied at the agricultural soils as fertilizers and pesticides. Such applications may result in the increase of heavy metals particularly Cd, Pb, and As. The objective of this study was to investigate the variability of chemical applications on Cd, Pb, and As concentrations of wheat-cultivated soils. Consequently, a study area was designed and was divided into four subareas (A, B, C, and D). The soil sampling was carried out in 40 points of cultivated durum wheat during the 2006-2007 periods. The samples were taken to the laboratory to measure their heavy metal concentration, soil texture, pH, electrical conductivity, cationic exchange capacity, organic matter, and carbonate contents. The result indicated that Cd, Pb, and As concentrations were increased in the cultivated soils due to fertilizer application. Although the statistical analysis indicates that these heavy metals increased significantly (P value<0.05), the lead and arsenic concentrations were increased dramatically compared to Cd concentration. This can be related to overapplication of fertilizers as well as the pesticides that are used to replant plant pests, herbs, and rats.

  7. Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination.

    PubMed

    Montiel-Rozas, M M; Madejón, E; Madejón, P

    2016-09-01

    Bioavailability of heavy metals can be modified by different root exudates. Among them, low molecular weight organic acids (LMWOAs) play an important role in this process. Three plant species (Poa annua, Medicago polymorpha and Malva sylvestris), potentially used for phytoremediation, have been assessed for both metal uptake and LMWOAs excretion in contaminated environments with different concentrations of Cd, Cu and Zn. The experiments have been carried out in washed sand and in three contaminated soils where two organic amendments were added (biosolid compost and alperujo compost). The most abundant LMWOAs excreted by all studied plants were oxalic and malic acids, although citric and fumaric acids were also detected. The general tendency was that plants responded to an increase of heavy metal stress releasing higher amounts of LMWOAs. This is an efficient exclusion mechanism reducing the metal uptake and allowing the plant growth at high levels of contamination. In the experiment using wash sand as substrate, the organic acids composition and quantity depended mainly on plant species and metal contamination. M. polymorpha was the species that released the highest concentrations of LMWOAs, both in sand and in soils with no amendment addition, whereas a decrease of these acids was observed with the addition of amendments. Our results established a clear effect of organic matter on the composition and total amount of LMWOAs released. The increase of organic matter and nutrients, through amendments, improved the soil quality reducing phytotoxicity. As a result, organic acids exudates decreased and were solely composed of oxalic acid (except for M. polymorpha). The release of LMWOAs has proved to be an important mechanism against heavy metal stress, unique to each species and modifiable by means of organic amendment addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Phytoremediation of heavy metal contaminated soil by Jatropha curcas.

    PubMed

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

    2014-12-01

    This study employed Jatropha curcas (bioenergy crop plant) to assist in the removal of heavy metals from contaminated field soils. Analyses were conducted on the concentrations of the individual metals in the soil and in the plants, and their differences over the growth periods of the plants were determined. The calculation of plant biomass after 2 years yielded the total amount of each metal that was removed from the soil. In terms of the absorption of heavy metal contaminants by the roots and their transfer to aerial plant parts, Cd, Ni, and Zn exhibited the greatest ease of absorption, whereas Cu, Cr, and Pb interacted strongly with the root cells and remained in the roots of the plants. J. curcas showed the best absorption capability for Cd, Cr, Ni, and Zn. This study pioneered the concept of combining both bioremediation and afforestation by J. curcas, demonstrated at a field scale.

  9. Soil washing and leaching: Heavy metal removal at several sites

    SciTech Connect

    Fristad, W.E.; Elliott, D.K.

    1995-12-31

    For this paper, soil washing is defined as the use of physical techniques to separate and surface clean soil particles. Soil leaching is considered to be the use of chemical techniques to dissolve, displace, and recover heavy metal contaminants which are adsorbed onto the surface of soil particles. The combination of physical and chemical techniques allows metal contaminants of most any type to be addressed both in laboratory-scale treatability studies as well as in a full-scale treatment plant. This presentation gives an overview of the combined soil washing and leaching approach and presents data from three different treatability studies and one full-scale project. The goal is to show how a standard set of physical and chemical steps were modified to successfully treat three out of four sites, all of which were contaminated by different means: battery breaking, steel making, ammunition manufacturing, and grenade testing.

  10. Enhancing the soil heavy metals removal efficiency by adding HPMA and PBTCA along with plant washing agents.

    PubMed

    Cao, Yaru; Zhang, Shirong; Wang, Guiyin; Li, Ting; Xu, Xiaoxun; Deng, Ouping; Zhang, Yanzong; Pu, Yulin

    2017-10-05

    Plant washing agents-water-extracted from Coriaria nepalensis (CN), Clematis brevicaudata (CB), Pistacia weinmannifolia (PW) and Ricinus communis (RC)-are feasible and eco-friendly for soil heavy metal removal, but their single application has limited removal efficiency. To improve their metal removal efficiencies, two biodegradable assistant agents, hydrolytic polymaleic anhydride (HPMA) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), were investigated in combination with plant washing agents through batch soil washing experiments. Results showed that the addition of HPMA or PBTCA with plant agents greatly enhanced the removal efficiencies of soil heavy metals (p<0.05). Under acidic conditions, the maximum improvements in soil heavy metal removal reached 18.69% and 18.00% for soil Cd and Zn by PW+HPMA, respectively, and 12.89% for soil Pb by CN+HPMA. Under neutral or alkaline conditions, the largest improvements in soil Cd, Pb and Zn were 24.18%, 54.38% and 25.47% by PW+PBTCA, respectively. When compared with EDTA, the loss rates of soil nitrogen, phosphorus and potassium significantly decreased (p<0.05) and the soil organic carbon significantly increased (p<0.05) after washing with the combinations. Hence, the addition of HPMA or PBTCA with the plant agents could improve the removal of soil heavy metals. Copyright © 2017. Published by Elsevier B.V.

  11. Humus-assisted cleaning of heavy metal contaminated soils

    NASA Astrophysics Data System (ADS)

    Borggaard, Ole K.; Rasmussen, Signe B.

    2016-04-01

    Contamination of soils with non-degradable heavy metals (HMs) because of human acticities is globally a serious problem threatening human health and ecosystem functioning. To avoid negative effects, HMs must be removed either on-site by plant uptake (phytoremediation) or off-site by extraction (soil washing). In both strategies, HM solubility must be augmented by means of a strong ligand (complexant). Often polycarboxylates such as EDTA and NTA are used but these ligands are toxic, synthetic (non-natural) and may promote HM leaching. Instead naturally occurring soluble humic substances (HS) were tested as means for cleaning HM contaminated soils; HS samples from beech and spruce litter, compost percolate and processed cow slurry were tested. Various long-term HM contaminated soils were extracted with solutions of EDTA, NTA or HS at different pH by single-step and multiple-step extraction mode. The results showed that each of the three complexant types increased HM solubility but the pH-dependent HM extraction efficiency decreased in the order: EDTA ≈ NTA > HS. However, the naturally occurring HS seems suitable for cleaning As, Cd, Cu and Zn contaminated soils both in relation to phytoremediation of moderately contaminated soils and washing of strongly contaminated soils. On the other hand, HS was found unsuited as cleaning agent for Pb polluted calcareous soils. If future field experiments confirm these laboratory results, we have a new cheap and environmentally friendly method for solving a great pollution problem, i.e. cleaning of heavy metal contaminated soils. In addition, humic substances possess additional benefits such as improving soil structure and stimulating microbial activity.

  12. Heavy Metal Bioavailability and Bioaccessibility in Soil

    NASA Astrophysics Data System (ADS)

    Dean, John Richard

    This chapter considers the use of a variety of approaches to assess either the bioavailability or the bioaccessibility of metals in soil. The bioavailability of metals from soils is considered with respect to a series of single-extraction methods, including the use of ethylenediaminetetraacetic acid (EDTA), acetic acid, diethylenetriaminepentaacetic acid (DTPA), ammonium nitrate, calcium chloride and sodium nitrate. Then, a procedure for the recovery of metals using a three-stage sequential extraction protocol is described. Two alternate approaches for assessing the environmental health risk to humans by undertaking in vitro gastrointestinal extraction (also known as the physiologically based extraction test, PBET) are considered. Finally, two acid digestion protocols that allow the pseudo-total metal content of samples to be assessed are provided.

  13. Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

    SciTech Connect

    Kuperman, R.; Parmelee, R.; Carreiro, M. ||

    1995-06-01

    The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the abundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lower in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.

  14. Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

    SciTech Connect

    Kuperman, R.; Parmelee, R.; Carreiro, M. ||

    1995-09-01

    The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the adundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lower in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.

  15. Study on the Effects of Irrigation with Reclaimed Water on the Content and Distribution of Heavy Metals in Soil.

    PubMed

    Lu, Shibao; Wang, Jianhua; Pei, Liang

    2016-03-08

    Reclaimed water is an important resource for irrigation, and exploration in making full use of it is an important way to alleviate water shortage. This paper analyzes the effects of irrigation with reclaimed water through field trials on the content and distribution of heavy metals in both tomatoes and the soil. By exploring the effects of reclaimed water after secondary treatment on the content and distribution characteristics of heavy metals in tomatoes and the heavy metal balance in the soil-crop system under different conditions, the study shows that there are no significant differences in the heavy metal content when the quantity of reclaimed water for irrigation varies. Reclaimed water for short-term irrigation does not cause pollution to either the soil environment or the crops. Nor will it cause the accumulation of heavy metals, and the index for the heavy metal content is far below the critical value of the national standard, which indicates that the vegetables irrigated with reclaimed water during their growth turn out to be free of pollutants. The heavy metals brought into the soil by reclaimed water are less than that taken away by the crops. The input and output quantities have only small effects on the heavy metal balance in the soil. This paper provides a reference for the evaluation and safety control of irrigation with reclaimed water.

  16. Study on the Effects of Irrigation with Reclaimed Water on the Content and Distribution of Heavy Metals in Soil

    PubMed Central

    Lu, Shibao; Wang, Jianhua; Pei, Liang

    2016-01-01

    Reclaimed water is an important resource for irrigation, and exploration in making full use of it is an important way to alleviate water shortage. This paper analyzes the effects of irrigation with reclaimed water through field trials on the content and distribution of heavy metals in both tomatoes and the soil. By exploring the effects of reclaimed water after secondary treatment on the content and distribution characteristics of heavy metals in tomatoes and the heavy metal balance in the soil-crop system under different conditions, the study shows that there are no significant differences in the heavy metal content when the quantity of reclaimed water for irrigation varies. Reclaimed water for short-term irrigation does not cause pollution to either the soil environment or the crops. Nor will it cause the accumulation of heavy metals, and the index for the heavy metal content is far below the critical value of the national standard, which indicates that the vegetables irrigated with reclaimed water during their growth turn out to be free of pollutants. The heavy metals brought into the soil by reclaimed water are less than that taken away by the crops. The input and output quantities have only small effects on the heavy metal balance in the soil. This paper provides a reference for the evaluation and safety control of irrigation with reclaimed water. PMID:27005639

  17. Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity.

    PubMed

    Gutiérrez, Carmen; Fernández, Carlos; Escuer, Miguel; Campos-Herrera, Raquel; Beltrán Rodríguez, M Eulalia; Carbonell, Gregoria; Rodríguez Martín, Jose Antonio

    2016-06-01

    Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs.

  18. Implications of soil pollution with heavy metals for public health

    NASA Astrophysics Data System (ADS)

    Juozulynas, Algirdas; Jurgelėnas, Antanas; Butkienė, Birutė; Greičiūtė, Kristina; Savičiūtė, Rasa

    2008-01-01

    Soil of military grounds is often polluted with heavy metals. Their concentrations may be dosens of times higher in polluted regions. The affected soils are permeable, so the pollutions can get into water and spread to the environment. Into human and animal organisms they can get with food and water. Heavy metals are very dangerous for people's health, and we must know their accumulation places, intensity of scatter and integral risk for health. The purpose of this work was to establish links between zones polluted with heavy metals and morbidity caused by pollution with heavy metals. The morbidity caused by heavy metals (Pb, Cu, Zn, Ca and other) in the polluted regions is 1.4-1.5 times higher for adults and teenagers and 1.5-3.9 times higher for children aged under 14 years than the mean morbidity of the same diseases in Lithuania. Hypothetically, it is possible to prognosticate that this problem will grow in future because the ratio of the newly registered and the existing cases of morbidity for children aged under 14 years is 1.3-1.5 times higher than for adults.

  19. [Immobilization impact of different fixatives on heavy metals contaminated soil].

    PubMed

    Wu, Lie-shan; Zeng, Dong-mei; Mo, Xiao-rong; Lu, Hong-hong; Su, Cui-cui; Kong, De-chao

    2015-01-01

    Four kinds of amendments including humus, ammonium sulfate, lime, superphosphate and their complex combination were added to rapid immobilize the heavy metals in contaminated soils. The best material was chosen according to the heavy metals' immobilization efficiency and the Capacity Values of the fixative in stabilizing soil heavy metals. The redistributions of heavy metals were determined by the European Communities Bureau of Referent(BCR) fraction distribution experiment before and after treatment. The results were as follows: (1) In the single material treatment, lime worked best with the dosage of 2% compared to the control group. In the compound amendment treatments, 2% humus combined with 2% lime worked best, and the immobilization efficiency of Pb, Cu, Cd, Zn reached 98.49%, 99.40%, 95.86%, 99.21%, respectively. (2) The order of Capacity Values was lime > humus + lime > ammonium sulfate + lime > superphosphate > ammonium sulfate + superphosphate > humus + superphosphate > humus > superphosphate. (3) BCR sequential extraction procedure results indicated that 2% humus combined with 2% lime treatment were very effective in immobilizing heavy metals, better than 2% lime treatment alone. Besides, Cd was activated firstly by 2% humus treatment then it could be easily changed into the organic fraction and residual fraction after the subsequent addition of 2% lime.

  20. [Distribution and migration of heavy metals in soil profiles by high-resolution sampling].

    PubMed

    Ruan, Xin-ling; Zhang, Gan-lin; Zhao, Yu-guo; Yuan, Da-gang; Wu, Yun-jin

    2006-05-01

    The vertical distribution of heavy metals in soils profiles is a result of heavy metals accumulation and migration under combining influence of edaphic factors and environmental conditions. It's an important basis for evaluation of heavy metals pollution and remediation of contaminated soils. By traditional sampling methods, i.e., soils were sampled according to pedogenetic horizons, only very general information about element migration can be learned. In the current study, three sites near a steel factory were selected to represent three types of land use, i.e. forest, dry land for vegetable cultivation and rice paddy field. Soils were sampled horizontally by high-resolution sampling method. In the top of 40 cm soils were sectioned in 2 cm intervals, then 5 cm intervals in next 40 cm, and 10 cm intervals in the last 20 cm of profile. Total content of Cu, Zn, Pb, Cr and Cd were determined, and the vertical distribution of Cu, Zn, Pb, Cr, Cd in every profile was analyzed. The results indicated that enrichment of heavy metals appeared in the upper most layer of the natural forest soil that without any anthropic disturbance, and this phenomenon proved that heavy metals were coming from atmospheric deposition. We found that Cu, Zn and Pb moved downward in a short distance, Cd migrated relatively faster than Cu, Zn and Pb, while Cr had no recognizable location of migration front. In the soil profiles of dry land and paddy field, there were influences of agricultural practice, the distribution and movement of metals were thus different form those of the forest soil. In cultivated layer heavy metals were evenly distributed because soils in the upper layer were mixed by cultivation, however, bellow the cultivated layer obvious migration took place again. It is concluded that different heavy metals have different mobility and there is such a relative order: Cd>Cu>Zn>Pb. The study shows that the distribution pattern can be obtained with the currently adopted high

  1. Heavy metal content in tea soils and their distribution in different parts of tea plants, Camellia sinensis (L). O. Kuntze.

    PubMed

    Seenivasan, Subbiah; Anderson, Todd Alan; Muraleedharan, Narayanannair

    2016-07-01

    Soils contaminated with heavy metals may pose a threat to environment and human health if metals enter the food chain over and above threshold levels. In general, there is a lack of information on the presence of heavy metals in tea [Camellia sinensis (L). O. Kuntze] plants and the soils in which they are grown. Therefore, an attempt was made to establish a database on the important heavy metals: cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb). For an initial survey on heavy metals, soil samples were collected randomly from tea-growing areas of Tamil Nadu, Kerala, and Karnataka, India. Parallel studies were conducted in the greenhouse on uptake of Pb, Cd, and Ni from soils supplemented with these metals at different concentrations. Finally, metal distribution in the tea plants under field conditions was also documented to assess the accumulation potential and critical limit of uptake by plants.

  2. White clover nodulation index in heavy metal contaminated soils- a potential bioindicator.

    PubMed

    Manier, Nicolas; Deram, Annabelle; Broos, Kris; Denayer, Franck-Olivier; Van Haluwyn, Chantal

    2009-01-01

    The morphological effects of heavy metal stress on the nodulation ability of Rhizobium spp. and growth of white clover (Trifolium repens L.) were studied in the laboratory under controlled conditions. Fourteen topsoils were collected from an area with elevated metal concentrations (Cd, Zn, and Pb). White clover was cultivated using a specialized "rhizotron" method to observe the development of root and nodule characteristics. Results show effects of increasing heavy metal concentrations on nodulation development, especially the nodulation index (i.e., the number of nodules per gram of the total fresh biomass). A significant decrease in nodulation index was observed at about 2.64 mg Cd kg(-1), 300 mg Zn kg(-1), and 130 mg Pb kg(-1) in these soils. The sensitivity of the nodulation index in relation to other morphological characteristics is discussed further. It is proposed that the nodulation index of white clover is a suitable bioindicator of increased heavy metal concentrations in soil.

  3. Chemometric interpretation of heavy metal patterns in soils worldwide.

    PubMed

    Skrbić, Biljana; Durisić-Mladenović, Natasa

    2010-09-01

    Principal component analysis (PCA) was applied on data sets containing levels of six heavy metals (Pb, Cu, Zn, Cd, Ni, Cr) in soils from different parts of the world in order to investigate the information captured in the global heavy metal patterns. Data used in this study consisted of the heavy metal contents determined in 23 soil samples from and around the Novi Sad city area in the Vojvodina Province, northern part of Serbia, together with those from the city of Banja Luka, the second largest city in Bosnia and Herzegovina, and the ones reported previously in the relevant literature in order to evaluate heavy metal distribution pattern in soils of different land-use types, as well as spatial and temporal differences in the patterns. The chemometric analysis was applied on the following input data sets: the overall set with all data gathered in this study containing 264 samples, and two sub sets obtained after dividing the overall set in accordance to the soil metal index, SMI, calculated here, i.e. the set of unpolluted soils having SMIs<100%, and the set of polluted soils with SMIs>100%. Additionally, univariate descriptive statistics and the Spearman's non-parametric rank correlation coefficients were calculated for these three sets. A Box-Cox transformation was used as a data pretreatment before the statistical methods applied. According to the results, it was seen that anthropogenic and background sources had different impact on the data variability in the case of polluted and unpolluted soils. The sample discrimination regarding the land-use types was more evident for the unpolluted soils than for the polluted ones. Using linear discriminant analysis, content of Cu was determined as a variable with a major discriminant capacity. The correct classification of 73.3% was achieved for predefined land-use types. Classification of the samples in accordance to the pollution level expressed as SMI was necessary in order to avoid the "masking" effect of the

  4. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants.

    PubMed

    Antonijević, Milan M; Marić, Miroslava

    2008-09-24

    Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust) were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe) in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds ) was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil.

  5. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants

    PubMed Central

    Antonijević, Milan M.; Marić, Miroslava

    2008-01-01

    Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust) were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe) in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds) was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil. PMID:27873845

  6. Soil macroinvertebrates as indicators of pollution by heavy metals.

    PubMed

    Nahmani, Johanne; Rossi, Jean-Pierre

    2003-03-01

    A broad range of soil pollutants were found to decrease with distance from a zinc smelter from 35,000 to 77, 8270 to 40 and from 190 to less than 1 ppm for zinc, lead and cadmium, respectively. Along this gradient, observed species richness of soil macro-organisms seemed to be more affected by the land-use type than by soil pollution--minimum in crops (21), maximum in woody sites (126). IndVal index allowed isolation of 21 indicator species from the 339 morphospecies identified. Most of these indicator species were characteristic of the unpolluted sites: only two diplopods and one gastropod from polluted poplar plantations, and none from the most polluted site. Since soil invertebrates respond to different environmental factors, including direct effect of heavy metals, we suggest there may be some confounding factors generating spurious relationships between the values of species as bioindicators and the pollution status they are supposed to indicate.

  7. Representing soil pollution by heavy metals using continuous limitation scores

    NASA Astrophysics Data System (ADS)

    Romić, Marija; Hengl, Tomislav; Romić, Davor; Husnjak, Stjepan

    2007-10-01

    The paper suggests a methodology to represent overall soil pollution in a sampled area using continuous limitation scores. The interpolated heavy metal concentrations are first transformed to limitation scores using the exponential transfer function determined by using two threshold values: permissible concentration (0 limitation points) and seriously polluted soil (4 limitation points). The limitation scores can then be summed to produce the map of cumulative limitation scores and visualize the most critically polluted areas. The methodology was illustrated using the 784 soil samples analyzed for Cd, Cr, Cu, Ni, Pb and Zn in the central region of Croatia. The samples were taken at 1×1 and 2×2 km grids and at fixed depths of 20 cm. Heavy metal concentrations in soil were determined by ICP-OES after microwave assisted aqua regia digestion. The sampled concentrations were interpolated using block regression-kriging with geology and land cover maps, terrain parameters and industrialization parameters as auxiliary predictors. The results showed that the best auxiliary predictors are geological map, ground water depth, NDVI and slope map and distance to urban areas. The spatial prediction was satisfactory for Cd, Ni, Pb and Zn, and somewhat less satisfactory for Cu and Cr. The final map of cumulative limitation scores showed that 33.5% of the total area is suitable for organic agriculture and 7.2% of the total area is seriously polluted by one or more heavy metals. This procedure can be used to assess suitability of soils for agricultural production and as a basis for possible legal commitments to maintain the soil quality.

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

    PubMed

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

    2013-12-01

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

  9. Heavy Metal Pollution in Urban Soils of Sopron

    NASA Astrophysics Data System (ADS)

    Horváth, Adrienn; Bidló, András

    2014-05-01

    Keywords: anthropogenic effects, land use types, heavy metal content, polluted urban soils, GIS methods Our aim was to identify the main feedback effects between the town and its environment. In the course of our investigation we have analysed the heavy metal contents of urban soil in Sopron town in Hungary. We collected 208 samples on 104 points from 0 to 10 and from 10 to 20 cm depth in a standard network and also at industrial territories. We have been represented our results in a GIS system. We analysed the soils with Lakanen-Erviö method and we measured 24 elements but we have been focused on Co, Cd, Cu, Pb and Zn. Using the data we observed the relationship between these elements in both layers. In the downtown the acidity of soils were alkaline by the greatest number of point, therefore the pollution of these soils is not leach in deeper layers yet. The lead was very high (> 100 mg Pb/kg) in both layers on the whole area of the town. Urban soils with high copper content (among 611 mg and 1221 mg Cu/kg) have been collected from garden and viticulture areas by us. Cadmium contents were the highest (6.14 mg Cd/kg) in traffic zones, where these values could be more than 3 mg Cd/kg according to the literature. The cobalt and zinc results were under the limits. According to our measurements we founded the highest average values in the soils of parks. This could be contamination of the lead from traffic, which bind in the soil of urban green spaces. Now we could continue our examinations with the investigations of these polluted green areas, which can effect to human health.

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

    PubMed

    Cang, Long; Zhou, Dong-Mei; Wang, Quan-Ying; Wu, Dan-Ya

    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(-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.

  11. Bioindication of heavy metals in soil by liverworts.

    PubMed

    Samecka-Cymerman, A; Marczonek, A; Kempers, A J

    1997-08-01

    Studies were made of the accumulation of the heavy metals Ba, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Sr, V, and Zn and the macroelements N, P, K, Ca, and Mg in liverworts Conocephalum conicum, Marchantia polymorphia, and Pellia epiphylla collected from 57 microhabitats in Poland (Lower Silesia, Tatry Mts., and Puszcza Augustowska forest) and one microhabitat in the Czech Republic (Moravsky Kras). Ecological differentiation of Conocephalum conicum, Marchantia polymorpha and Pellia epiphylla populations is closely correlated with the soil chemistry. The evidence for this assumption are the significant positive correlations between concentrations of elements in soil and in the examined liverworts. In particular, correlations between contents of chromium and cobalt in soil and in Conocephalum conicum and between nickel, chromium, copper, and barium in soil and in Pellia epiphylla prove that these plants can be useful in monitoring of contamination of soil with elements mentioned above. Concentrations of cobalt in almost all the examined liverworts surpass the average background values of this element established for terrestrial bryophytes what proves that these plants tolerate increased accumulated amounts of this element and may therefore act as bioindicator for this heavy metal. Cationic equilibrium of Conocephalum conicum, Marchantia polymorpha and Pellia epiphylla examined according to Czarnowski (1977) pointed to the existence of some disturbances in ionic balance of these plants caused probably by elevated concentrations of microelements (especially iron, cobalt, lead, and copper) in their tissues.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  13. Growth of Jatropha curcas on heavy metal contaminated soil amended with industrial wastes and Azotobacter. A greenhouse study.

    PubMed

    Kumar, G P; Yadav, S K; Thawale, P R; Singh, S K; Juwarkar, A A

    2008-04-01

    The aims of the study were to evaluate the effect of organic wastes (biosludge and dairy sludge) and biofertilizer (Azotobacter chroococcum) on the planting conditions of Jatropha curcas in metal contaminated soils. Results showed that the plants survival rate in heavy metal contaminated soil increased with addition of amendments. Treatment T6 (heavy metal contaminated soils+dairy sludge+biofertilizer) observed to be the best treatment for growth (height and biomass) as compared with the treatment T5 (heavy metal contaminated soils+biosludge+biofertilizer). In addition, organic amendments provided nutrients such as carbon, N, P and K to support plant growth and reduced the metal toxicity to plant. The present study showed that metal contaminated lands/soils could be suitably remediated by adapting appropriate measures.

  14. Heavy metals in urban soils of the Granada city (Spain)

    NASA Astrophysics Data System (ADS)

    Delgado, Gabriel; Sánchez-Marañón, Manuel; Bech, Jaume; Sartini, Alessandra; Martín-García, Juan Manuel; Delgado, Rafael

    2013-04-01

    Urban soils (Anthrosols, Technosols, and the remaining natural patches) are essential components of the city ecosystems influencing the quality of life for people. Unfortunately, because of the high concentration of matter and energy that occurs in any city, these soils might accumulate potentially toxic pollutants such as heavy metals, organic compounds, pathogens, pharmaceuticals, and soluble salts. Contamination by heavy metals has been considered especially dangerous because they can affect human health via inhalation of dust, ingestion, or skin contact with soils. Children are the more exposed citizens in gardens and parks. Accordingly, our objective was to analyze the content of heavy metals in soils of the two most emblematic, extensive, and visited landscaped areas of the Granada city (Salón Garden, which dates back to 1612, and Federico García Lorca Park, opened since 1993) for assessing the health hazard. Using a composite sampling of 20-30 points chosen at random, we collected the upper soil (10 cm) of five representative plots for each landscaped area. We determined soil characteristics by routine procedures and metal elements using ICP-mass. From high to low concentration we found Mn, Ba, Pb, Zn, V, Sn, Cr, Cu, Ni, Sb, Y, As, Sc, Co, Th, Au, U, Mo, Be, Bi, Tl, Cd, and In; the first 10 metals ranging between 478 and 22 ppm. Mn, Ba, and other trace elements were strongly correlated with soil properties suggesting the inheritance as a possible source of metal variation, especially in the soils of younger Park, where the materials used to build gardens in the five sampled plots seemed to be more variable (carbonates: 10-40%, clay: 18-26%, pH: 7.6-7.9, organic matter: 3-7%, free iron 0.5-1.1%). The content of many other metals measured in the sampled plots, however, were independent of soil material and management. On the other hand, compared to agricultural and native soils of the surroundings, our urban soils had obviously greater content in organic

  15. Characterization of heavy metal contamination in the soil and sediment of the Three Gorges Reservoir, China.

    PubMed

    Wang, Tujin; Pan, Jin; Liu, Xuelian

    2017-02-23

    This paper analyzes the concentration, distribution, bioavailability, and potential heavy metal contamination risk of Cu, Pb, Cd, Zn, and Cr in the soil and sediment of the Three Gorges Reservoir (TGR). In this paper, 14 stations that cover the upper reaches to the lower reaches of the TGR were selected. The spatial distribution of heavy metals in the TGR showed that the average concentrations of Cu, Pb, Cd, Zn, and Cr were higher in the upper and lower reaches than those in the middle reaches because of industrial and agricultural activities as well as natural processes (e.g., soil erosion, rock weathering). The results also indicated that multiple pollution sources and complex geomorphological, geochemical and biological processes resulted in remarkably higher heavy metal concentrations in the soils of the water-level-fluctuation zone (WLFZ) than in the soils of the banks. The Cu, Pb, Cd, Zn, and Cr concentrations in the soils of the TGR did not exceed their respective maximum allowable concentration (MAC) values for agricultural soils in China, indicating that the soil in the TGR was not seriously contaminated with Cu, Pb, Cd, Zn, or Cr. However, the mean concentrations of all the studied metals in the sediments were higher than the geochemical background values and much higher than those in the soils, thus indicating the effect of the pollution sources and the altered hydrologic conditions that occurred after the impoundment of the TGR. A geoaccumulation index analysis indicated that the TGR sediments were moderately polluted with Cu and Cd, unpolluted to moderately polluted with Pb and Cr, and unpolluted with Zn. Fractionation studies indicated that Cd was mainly present in the non-residual fractions and exhibited great instability and bioavailability; furthermore, the alternating wetting and drying of the WFLZ soils enhance the mobility and bioavailability of Cd. Thus, greater attention should be paid to Cd pollution in the TGR because of its higher risk

  16. Biogeochemistry of heavy metals in contaminated excessively moistened soils (Analytical review)

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Plekhanova, I. O.

    2014-03-01

    The biogeochemical behavior of heavy metals in contaminated excessively moistened soils depends on the development of reducing conditions (either moderate or strong). Upon the moderate biogenic reduction, Cr as the metal with variable valence forms low-soluble compounds, which decreases its availability to plants and prevents its penetration into surface- and groundwater. Creation of artificial barriers for Cr fixation on contaminated sites is based on the stimulation of natural metal-reducing bacteria. Arsenic, being a metalloid with a variable valence, is mobilized upon the moderate biogenic reduction. The mobility of siderophilic heavy metals with a constant valence grows under the moderate reducing conditions at the expense of dissolution of iron (hydr)oxides as carriers of these metals. Zinc, which can enter the newly formed goethite lattice, is an exception. Strong reduction processes in organic excessively moist and flooded soils (usually enriched in S) lead to the formation of low-soluble sulfides of heavy elements with both variable (As) and constant (Cu, Ni, Zn, and Pb) valence. On changing aquatic regime in overmoistened soils and their drying, sulfides of heavy metals are oxidized, and previously fixed metals are mobilized.

  17. Monometal and competitive adsorption of heavy metals by sewage sludge-amended soil.

    PubMed

    Antoniadis, Vasileios; Tsadilas, Christos D; Ashworth, Daniel J

    2007-06-01

    Sewage sludge-amended soils may alter their ability to adsorb heavy metals over time, due to the decomposition of sludge-borne organic matter. Thus, we studied Cd, Ni, and Zn adsorption by a sewage sludge-amended soil (Typic Xerofluvent) before and after one-year incubation in both monometal and competitive systems. In the monometal system, the order of decreasing sorption was Zn>Cd>Ni. Competition significantly reduced metal K(d), especially that of Cd which decreased by nearly 50%. Over the course of the incubation there was a 31% reduction of soil organic matter content. At the same time, in competitive systems Cd K(d) significantly decreased, while Zn K(d) significantly increased, and Ni K(d) remained unaffected. This study shows that sewage sludge-amended soils may change in their ability to sorb heavy metals over time at high metal concentrations. The data suggest that Cd is likely to be of most environmental significance in such soils, since it exhibited decreased sorption under competitive conditions and as the organic matter content of the soil was reduced. The potential for long-term release of metals should be considered in the risk assessment associated with sewage sludge addition to soils, particularly in climates where degradation of organic matter is likely to be enhanced.

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

    PubMed

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

    2017-09-05

    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.

  19. Soil carbon sequestration estimated with the soil conditioning index

    USDA-ARS?s Scientific Manuscript database

    Rapid and reliable assessments of the potential of different agricultural management systems to sequester soil organic carbon are needed to promote conservation and help mitigate greenhouse gas emissions. The soil conditioning index (SCI) is a relatively simple model to parameterize and is currentl...

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Chemical methods and phytoremediation of soil contaminated with heavy metals.

    PubMed

    Chen, H M; Zheng, C R; Tu, C; Shen, Z G

    2000-07-01

    The effects of chemical amendments (calcium carbonate (CC), steel sludge (SS) and furnace slag (FS)) on the growth and uptake of cadmium (Cd) by wetland rice, Chinese cabbage and wheat grown in a red soil contaminated with Cd were investigated using a pot experiment. The phytoremediation of heavy metal contaminated soil with vetiver grass was also studied in a field plot experiment. Results showed that treatments with CC, SS and FS decreased Cd uptake by wetland rice, Chinese cabbage and wheat by 23-95% compared with the unamended control. Among the three amendments, FS was the most efficient at suppressing Cd uptake by the plants, probably due to its higher content of available silicon (Si). The concentrations of zinc (Zn), lead (Pb) and Cd in the shoots of vetiver grass were 42-67%, 500-1200% and 120-260% higher in contaminated plots than in control, respectively. Cadmium accumulation by vetiver shoots was 218 g Cd/ha at a soil Cd concentration of 0.33 mg Cd/kg. It is suggested that heavy metal-contaminated soil could be remediated with a combination of chemical treatments and plants.

  2. Aldehyde dehydrogenase expression in Metaphire posthuma as a bioindicator to monitor heavy metal pollution in soil.

    PubMed

    Panday, Raju; Bhatt, Padam Shekhar; Bhattarai, Tribikram; Shakya, Kumudini; Sreerama, Lakshmaiah

    2016-11-21

    Soil contamination and associated pollution plays a detrimental role in soil flora and fauna. Soil is processed and remodeled by subterranean earthworms, accordingly are referred to as soil chemical engineers. These worms, besides processing carbon and nitrogen, serve as minors for processing metals. In heavy metal contaminated soils, they accumulate heavy metals, which in turn cause altered gene expression, including aldehyde dehydrogenase (ALDH) enzymes. This study explores the possibility of ALDH expression in earthworms as a novel biomarker for the heavy metal contamination of soil. Earthworms cultured in contaminated soils accumulated significantly higher levels of Pb and Cd. Similarly, significantly higher levels of ALDH enzyme activities were observed in earthworms cultured in soils contaminated with Pb and Cd. The ALDH activity was found to be highest in worms cultured in 5 ppm heavy metal contaminated soils. Although, ALDH activities decreased as the heavy metal concentration in soil increased, they were significantly higher when compared to control worms cultured in uncontaminated soils. The accumulation of heavy metal in earthworms measured after 28 days decreased as the heavy metal concentration in soil increased. Levels of ALDH expression correlated with total Pb and Cd concentration in the earthworm tissue. This study showed that the ALDH activity in earthworms could potentially be used as a biomarker to show heavy metal pollution in soil.

  3. Heavy metals contamination of soils surrounding waste deposits in Romania

    NASA Astrophysics Data System (ADS)

    Matache, M.; Rozylowicz, L.; Ropota, M.; Patroescu, C.

    2003-05-01

    Soils contamination with heavy metals is one of the most severe aspects of environmental pollution in Romania, independently of the origin sources (domestic or industrial activities) or type of disposal (organised landfill or hazardous deposits)[l-2]. This fact is the consequence of the poor state of the existing waste deposits in Romania and of the significant costs involved by the establishing of a new landfill according with the international regulations. The present study is trying to emphasise the contamination of soils surrounding different categories of waste deposits (sewage sludge ponds, domestic and industrial waste landfills, hillocks, sterile deposits) from various regions of Romania. Some case studies show a special interest being localise in a protected area (Iron Gates Natural Park). In order to quantify the concentration of metals like Cd, Cr, Cu, Pb, Zn, Ni, Mo in soil samples, analysis were performed using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). Romanian standards were used as reference values[3].

  4. Botanical plants could rid soil of heavy metals

    SciTech Connect

    Brennan, M.

    1993-04-20

    A new technology that is now emerging holds promise of revolutionizing the remediation of soils contaminated with heavy metals. Called phytoremediation, it would use green plants to remove the metals. Plants take up the metals in their roots and translocate them to their shoots, which are harvested, burned in a kiln, and the metals recovered and recycled. The challenge is finding or engineering plants that can absorb, translocate, and tolerate heavy metals while producing enough foliage to make the process efficient. All plants take up small amounts of metals, he notes. What he looks for are weird plants that can accumulate them. Such plants exist, he says, giving credence to the feasibility of phytoremediation. Naturally occurring plants with spectacular metal uptake have been found growing on ore outcroppings, he explains. Cunningham scouts waste repositories and mining and industrial sites for metal-accumulating plant species. So far, he has identified two common weeds - hemp dogbane and ragweed - as candidates for remediating lead-contaminated soils. Both plants accumulate lead, he says, but their abilities vary across soils because lead exists in several forms in soil, and not all of its forms are easily absorbed. He finds that lowering the pH and the phosphate and sulfate content of the soil enhances uptake of the metal. The downside is these changes can impair the plant's nutritional environment. So, the chemistry of the soil must be carefully manipulated to boost metal uptake without losing plant biomass, he emphasizes. Cunningham's scheme is being field-tested at Chambers Works, a Due Pont facility in New Jersey. If ragweed proves to be the species of choice for remediating weapons sites and other lead-contaminated sites, he says allergy sufferers needn't worry. Only mutants of the weed that don't pollinate will be grown.

  5. Leaching of heavy metals from contaminated soils: an experimental and modeling study.

    PubMed

    Dijkstra, Joris J; Meeussen, Johannes C L; Comans, Rob N J

    2004-08-15

    In this paper, we characterize the leaching of heavy metals (Ni, Cu, Zn, Cd, and Pb) from eight contaminated soils over a wide range of pH (pH 0.4-12) using an original approach based on batch pH-static leaching experiments in combination with selective chemical extractions and geochemical modeling. The leached concentrations of the heavy metals are generally much lower than the total concentrations and show a strong pH dependency, resulting in "V-shaped" leaching curves with orders of magnitude changes in solution concentrations. The "multisurface" model used incorporates adsorption to dissolved and solid organic matter (NICA-Donnan), iron/aluminum (hydr)oxide (generalized two-layer model) and clay (Donnan model). These models were applied without modifications, and only the standard set of binding constants and parameters was used (i.e., without any fitting). The model predictions of heavy metal leaching are generally adequate and sometimes excellent. Results from speciation calculations are consistent with the well-recognized importance of organic matter as the dominant reactive solid phase in soils. The observed differences between soils with respect to element speciation in the solid phase correspond to the relative amounts of the reactive surfaces present in the soils. In the solution phase, complexes with dissolved organic matter (DOM) are predominant over most of the pH range. Free metal ions (Me2+) are generally the dominant species below pH 4. The combination of the experimental and modeling approach as used in this study is shown to be promising because it leads to a more fundamental understanding of the pH-dependent leaching processes in soils. The "multisurface" modeling approach, with the selected sorption models, is shown to be able to adequately predict the leaching of heavy metals from contaminated soils over a wide range of conditions, without any fitting of parameters.

  6. Ancient Heavy Metal Contamination in Soils as a Driver of Tolerant Anthyllis vulneraria Rhizobial Communities.

    PubMed

    Mohamad, Roba; Maynaud, Geraldine; Le Quéré, Antoine; Vidal, Céline; Klonowska, Agnieszka; Yashiro, Erika; Cleyet-Marel, Jean-Claude; Brunel, Brigitte

    2017-01-15

    Anthyllis vulneraria is a legume associated with nitrogen-fixing rhizobia that together offer an adapted biological material for mine-soil phytostabilization by limiting metal pollution. To find rhizobia associated with Anthyllis at a given site, we evaluated the genetic and phenotypic properties of a collection of 137 rhizobia recovered from soils presenting contrasting metal levels. Zn-Pb mine soils largely contained metal-tolerant rhizobia belonging to Mesorhizobium metallidurans or to another sister metal-tolerant species. All of the metal-tolerant isolates harbored the cadA marker gene (encoding a metal-efflux PIB-type ATPase transporter). In contrast, metal-sensitive strains were taxonomically distinct from metal-tolerant populations and consisted of new Mesorhizobium genospecies. Based on the symbiotic nodA marker, the populations comprise two symbiovar assemblages (potentially related to Anthyllis or Lotus host preferences) according to soil geographic locations but independently of metal content. Multivariate analysis showed that soil Pb and Cd concentrations differentially impacted the rhizobial communities and that a rhizobial community found in one geographically distant site was highly divergent from the others. In conclusion, heavy metal levels in soils drive the taxonomic composition of Anthyllis-associated rhizobial populations according to their metal-tolerance phenotype but not their symbiotic nodA diversity. In addition to heavy metals, local soil physicochemical and topoclimatic conditions also impact the rhizobial beta diversity. Mesorhizobium communities were locally adapted and site specific, and their use is recommended for the success of phytostabilization strategies based on Mesorhizobium-legume vegetation. Phytostabilization of toxic mine spoils limits heavy metal dispersion and environmental pollution by establishing a sustainable plant cover. This eco-friendly method is facilitated by the use of selected and adapted cover crop legumes

  7. Ancient Heavy Metal Contamination in Soils as a Driver of Tolerant Anthyllis vulneraria Rhizobial Communities

    PubMed Central

    Mohamad, Roba; Maynaud, Geraldine; Le Quéré, Antoine; Vidal, Céline; Klonowska, Agnieszka; Yashiro, Erika; Cleyet-Marel, Jean-Claude

    2016-01-01

    ABSTRACT Anthyllis vulneraria is a legume associated with nitrogen-fixing rhizobia that together offer an adapted biological material for mine-soil phytostabilization by limiting metal pollution. To find rhizobia associated with Anthyllis at a given site, we evaluated the genetic and phenotypic properties of a collection of 137 rhizobia recovered from soils presenting contrasting metal levels. Zn-Pb mine soils largely contained metal-tolerant rhizobia belonging to Mesorhizobium metallidurans or to another sister metal-tolerant species. All of the metal-tolerant isolates harbored the cadA marker gene (encoding a metal-efflux PIB-type ATPase transporter). In contrast, metal-sensitive strains were taxonomically distinct from metal-tolerant populations and consisted of new Mesorhizobium genospecies. Based on the symbiotic nodA marker, the populations comprise two symbiovar assemblages (potentially related to Anthyllis or Lotus host preferences) according to soil geographic locations but independently of metal content. Multivariate analysis showed that soil Pb and Cd concentrations differentially impacted the rhizobial communities and that a rhizobial community found in one geographically distant site was highly divergent from the others. In conclusion, heavy metal levels in soils drive the taxonomic composition of Anthyllis-associated rhizobial populations according to their metal-tolerance phenotype but not their symbiotic nodA diversity. In addition to heavy metals, local soil physicochemical and topoclimatic conditions also impact the rhizobial beta diversity. Mesorhizobium communities were locally adapted and site specific, and their use is recommended for the success of phytostabilization strategies based on Mesorhizobium-legume vegetation. IMPORTANCE Phytostabilization of toxic mine spoils limits heavy metal dispersion and environmental pollution by establishing a sustainable plant cover. This eco-friendly method is facilitated by the use of selected and adapted

  8. America's Soil and Water: Condition and Trends.

    ERIC Educational Resources Information Center

    1981

    A review of conditions and trends regarding soil and water resources of rural nonfederal lands of the United States is presented in this publication. Maps, charts, and graphs illustrate the data collected on various aspects of soil and water use and practice. Topic areas considered include: (1) land use patterns; (2) classes of land; (3)…

  9. Heavy metal removal by GLDA washing: Optimization, redistribution, recycling, and changes in soil fertility.

    PubMed

    Wang, Guiyin; Zhang, Shirong; Xu, Xiaoxun; Zhong, Qinmei; Zhang, Chuer; Jia, Yongxia; Li, Ting; Deng, Ouping; Li, Yun

    2016-11-01

    Soil washing, an emerging method for treating soils contaminated by heavy metals, requires an evaluation of its efficiency in simultaneously removing different metals, the quality of the soil following remediation, and the reusability of the recycled washing agent. In this study, we employed N,N-bis (carboxymethyl)-l-glutamic acid (GLDA), a novel and readily biodegradable chelator to remove Cd, Pb, and Zn from polluted soils. We investigated the influence of washing conditions, including GLDA concentration, pH, and contact time on their removal efficiencies. The single factor experiments showed that Cd, Pb, and Zn removal efficiencies reached 70.62, 74.45, and 34.43% in mine soil at a GLDA concentration of 75mM, a pH of 4.0, and a contact time of 60min, and in polluted farmland soil, removal efficiencies were 69.12, 78.30, and 39.50%, respectively. We then employed response surface methodology to optimize the washing parameters. The optimization process showed that the removal efficiencies were 69.50, 88.09, and 40.45% in mine soil and 71.34, 81.02, and 50.95% in polluted farmland soil for Cd, Pb, and Zn, respectively. Moreover, the overall highly effective removal of Cd and Pb was connected mainly to their highly effective removal from the water-soluble, exchangeable, and carbonate fractions. GLDA-washing eliminated the same amount of metals as EDTA-washing, while simultaneously retaining most of the soil nutrients. Removal efficiencies of recycled GLDA were no >5% lower than those of the fresh GLDA. Therefore, GLDA could potentially be used for the rehabilitation of soil contaminated by heavy metals. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Partitioning of heavy metals in a soil contaminated by slag: A redistribution study

    SciTech Connect

    Bunzl, K.; Trautmannsheimer, M.; Schramel, P.

    1999-08-01

    In order to interpret reasonably the partitioning of heavy metals in a contaminated soil as observed from applying a sequential extraction procedure, information on possible redistribution processes of the metals during the various extraction steps is essential. For this purpose, sequential extraction was used to study the chemical partitioning of Ag, Cu, Ni, Pb, and Zn in a soil contaminated wither by a slag from coal firing or by a slag from pyrite roasting. Through additional application of sequential extraction to the pure slags as well as to the uncontaminated soil, it was shown that during the various extraction steps applied to the soil/slag mixtures, substantial redistribution processes of the metals between the slag- and soil particles can occur. In many cases, metals ions released during the extraction with acid hydroxylamine or acid hydrogen peroxide are partially readsorbed by solid constituents of the mixture and will therefore be found in the subsequent fractions extracted. As a result, one has to realize that (1) it will be difficult to predict the chemical partitioning of these metals in contaminated soils by investigating pure slags only, and (2) information on the partitioning of a metal in a slag contaminated soil will not necessarily give any relevant information on the form of this metal in the slag or in the slag/soil mixture, because the redistribution processes during sequential extraction will not be the same as those occurring in the soil solution under natural conditions.

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

    SciTech Connect

    Peters, R.W.; Shem, L.

    1993-03-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

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

    SciTech Connect

    Peters, R.W.; Shem, L.

    1993-01-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

  13. Effect of moisture regime on the redistribution of heavy metals in paddy soil.

    PubMed

    Zheng, Shunan; Zhang, Mingkui

    2011-01-01

    Sequential extraction procedure was applied to assess the dynamics of solid-phase transformation of added Cu, Pb, Cd, and Hg in a typical Chinese paddy soil incubated under three moisture regimes (75% field capacity, wetting-drying cycle, and flooding). The heavy metals spiked in the soil were time-dependently transferred from the easily extractable fraction (the exchangeable fraction) into less labile fractions (Fe-Mn oxide- and organic matter-bound fractions), and thus reduced lability of the metals. No significant changes were found for the carbonate-bound and residual fractions of the heavy metals in the soil during the whole incubation. Change rate of the mobility factor (MF), a proportion of weakly bound fractions (exchangeable and carbonate-bound) in the total metal of soil, reflected the transformation rate of metal speciation from the labile fractions toward stable fractions. It was found that soil moisture regime did not change the direction and pathways of transformation of metal speciation, but it significantly affected the transformation rate. In general, the paddy soil under flooding regime had higher metal reactivity compared with 75% field capacity and wetting-drying cycle regimes, resulting in the more complete movement of metals toward stable fractions. This might be related to the increased pH, precipitation of the metals with sulfides and higher concentration of amorphous Fe oxides under submerged condition.

  14. Toxicity testing of heavy-metal-polluted soils with algae Selenastrum capricornutum: a soil suspension assay.

    PubMed

    Aruoja, Villem; Kurvet, Imbi; Dubourguier, Henri-Charles; Kahru, Anne

    2004-08-01

    A small-scale Selenastrum capricornutum (Rhapidocelis subcapitata) growth inhibition assay was applied to the toxicity testing of suspensions of heavy-metal-polluted soils. The OECD 201 standard test procedure was followed, and algal biomass was measured by the fluorescence of extracted chlorophyll. The soils, which contained up to (per kilogram) 1390 mg of Zn, 20 mg of Cd, and 1050 mg of Pb were sampled around lead and zinc smelters in northern France. The water extractability of the metals in suspensions (1 part soil/99 parts water w/v) was not proportional to the pollution level, as extractability was lower for soil samples that were more polluted. Thus, the same amount of metals could be leached out of soils of different levels of pollution, showing that total concentrations of heavy metals in soil (currently used for risk assessment purposes) are poor predictors of the real environmental risk via the soil-water path. Despite high concentrations of water-extracted zinc (0.6-1.4 mg/L of Zn in the test), exceeding by approximately 10-fold the EC(50) value for S. capricornutum (0.1 mg Zn/L), 72-h algal growth in the soil extracts was comparable or better than growth in the standard control OECD mineral medium. The soil suspension stimulated the growth of algae up to eightfold greater than growth using the OECD control medium. Growth stimulation of algae was observed even when soil suspensions contained up to 12.5 mg Zn/L and could not be explained by supplementary nitrogen, phosphorous, and carbonate leached from the soil. However, if the growth of algae in suspensions of clean and polluted soils was compared, a dose-dependent inhibitory effect of metals on algal growth was demonstrated. Thus, as soil contains nutrients/supplements that mask the adverse effect of heavy metals, a clean soil that has properties similar to the polluted soils should be used instead of mineral salt solution as a control for analysis of the ecotoxicity of soils. Copyright 2004 Wiley

  15. Proteomic analysis of eucalyptus leaves unveils putative mechanisms involved in the plant response to a real condition of soil contamination by multiple heavy metals in the presence or absence of mycorrhizal/rhizobacterial additives.

    PubMed

    Guarino, Carmine; Conte, Barbara; Spada, Valentina; Arena, Simona; Sciarrillo, Rosaria; Scaloni, Andrea

    2014-10-07

    Here we report on the growth, accumulation performances of, and leaf proteomic changes in Eucalyptus camaldulensis plants harvested for different periods of time in an industrial, heavy metals (HMs)-contaminated site in the presence or absence of soil microorganism (AMs/PGPRs) additives. Data were compared to those of control counterparts grown in a neighboring nonpolluted district. Plants harvested in the contaminated areas grew well and accumulated HMs in their leaves. The addition of AMs/PGPRs to the polluted soil determined plant growth and metal accumulation performances that surpassed those observed in the control. Comparative proteomics suggested molecular mechanisms underlying plant adaptation to the HMs challenge. Similarly to what was observed in laboratory-scale investigations on other metal hyperaccumulators but not on HMs-sensitive plants, eucalyptus grown in the contaminated areas showed an over-representation of enzymes involved in photosynthesis and the Calvin cycle. AMs/PGPRs addition to the soil increased the activation of these energetic pathways, suggesting the existence of signaling mechanisms that address the energy/reductive power requirement associated with augmented growth performances. HMs-exposed plants presented an over-representation of antioxidant enzymes, chaperones, and proteins involved in glutathione metabolism. While some antioxidant enzymes/chaperones returned to almost normal expression values in the presence of AMs/PGPRs or in plants exposed to HMs for prolonged periods, proteins guaranteeing elevated glutathione levels were constantly over-represented. These data suggest that glutathione (and related phytochelatins) could act as key molecules for ensuring the effective formation of HMs-chelating complexes that are possibly responsible for the observed plant tolerance to metal stresses. Overall, these results suggest potential genetic traits for further selection of phytoremediating plants based on dedicated cloning or breeding

  16. Mutagenic activity of heavy metals in soils of wayside slopes

    NASA Astrophysics Data System (ADS)

    Fedorova, A. I.; Kalaev, V. N.; Prosvirina, Yu. G.; Goryainova, S. A.

    2007-08-01

    The genotoxic properties of soils polluted with heavy metals were studied on two wayside slopes covered with trees in the city of Voronezh. The nucleolar test in cells of the apical meristem of Zebrina pendula Schnizl. roots was used. The genotoxic effect of the soils was revealed according to the increased number of 2-and 3-nucleolar cells (from 41 to 54% and from 19 to 23% in the upper part of the first and second slopes, respectively; in the control, their number was 18 and 7%). The mean number of nucleoli per cell increased from 1.7 to 1.95 in the experiment and 1.31 in the control. The increased vehicle emissions, especially when cars go up the slopes (mainly in the upper and middle parts), correlated with the elevated heavy metal (Pb, Cu, Cd, and Zn) contents in the soil. The mutagenic substances may be removed to the Voronezh Reservoir, where they may be accumulated in some living organisms.

  17. Heavy metals content in degraded agricultural soils of a mountain region related to soil properties

    NASA Astrophysics Data System (ADS)

    Navarro-Pedreño, José; Belén Almendro-Candel, María; Gómez, Ignacio; Jordán, Manuel M.; Bech, Jaume; Zorpas, Antonis

    2017-04-01

    Agriculture has been practiced for long time in Mediterranean regions. Intensive agriculture and irrigation have developed mainly in the valleys and coastal areas. In the mountainous areas, dry farming has been practiced for centuries. Soils have been fertilized using mainly organic amendments. Plants extracted nutrients and other elements like heavy metals presented in soils and agricultural practices modified soil properties that could favor the presence of heavy metals. In this work, it has been checked the content of heavy metals in 100 agricultural soils samples of the NorthWest area of the province of Alicante (Spain) which has been long cultivated with cereals and olive trees, and now soils are abandoned and degraded because of the low agricultural yields. European policy has the aim to improve the sustainable agriculture and recover landscapes of mountain regions. So that, it is important to check the state of the soils (Marques et al. 2007). Soils samples (arable layer) were analyzed determining: pH (1:5, w/v, water extract), equivalent calcium carbonate content, organic matter by Walkley-Black method (Nelson and Sommers 1996), micronutrients (Cu, Fe, Mn, Zn) extracted with DTPA (Lindsay and Norvell, 1978) and measured by atomic absorption spectrometry, and total content of metals (Cd, Cr, Ni, Pb) measured in soil samples after microwave acid digestion (Moral et al. 1996), quantifying the content of metals by ICP analysis. The correlation between soil properties and metals. The results indicated that pH and carbonates are the most important properties of these soils correlated with the metals (both micronutrients and heavy metals). The available micronutrients (all of them) are close correlated with the pH and carbonates in soils. Moreover, heavy metals like Pb and Ni are related to available Mn and Zn. Keywords: pH, carbonates, heavy metals, abandoned soils. References: Lindsay,W.L., andW.A. Norvell. 1978. "Development of a DTPA Soil Test for Zinc, Iron

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

    PubMed

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

    2017-01-01

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

  19. Influence of the selective EDTA derivative phenyldiaminetetraacetic acid on the speciation and extraction of heavy metals from a contaminated soil.

    PubMed

    Zhang, Tao; Wei, Hang; Yang, Xiu-Hong; Xia, Bing; Liu, Jun-Min; Su, Cheng-Yong; Qiu, Rong-Liang

    2014-08-01

    The development of more selective chelators for the washing of heavy metal contaminated soil is desirable in order to avoid excessive dissolution of soil minerals. Speciation and mobility of Cu, Zn, Pb, and Ni in a contaminated soil washed with phenyldiaminetetraacetic acid (PDTA), a derivative of EDTA, were investigated by batch leaching test using a range of soil washing conditions followed by sequential extraction. With appropriate washing conditions, PDTA significantly enhanced extraction of Cu from the contaminated soil. The primary mechanisms of Cu extraction by PDTA were complexation-promoted dissolution of soil Cu and increased dissolution of soil organic matter (SOM). PDTA showed high selectivity for Cu(II) over soil component cations (Ca(II), Mg(II), Fe(III), Mn(II), Al(III)), especially at lower liquid-to-soil ratios under PDTA deficiency, thus avoiding unwanted dissolution of soil minerals during the soil washing process which can degrade soil structure and interfere with future land use. PDTA-enhanced soil washing increased the exchangeable fractions of Cu, Zn, and Pb and decreased their residual fractions, compared to their levels in unwashed soil. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Sorption interactions of heavy metals with biochar in soil remediation studies

    NASA Astrophysics Data System (ADS)

    Fristak, Vladimir; Friesl-Hanl, Wolfgang; Wawra, Anna; Soja, Gerhard

    2015-04-01

    The search for new materials in soil remediation applications has led to new conversion technologies such as carbonization and pyrolysis. Biochar represents the pyrolytic product of different biomass input materials processed at 350-1000°C and anoxic conditions. The pyrolysis temperature and feedstock have a considerable influence on the quality of the charred product and also its main physico-chemical properties. Biochar as porous material with large specific surface and C-stability is utilized in various environmental and agricultural technologies. Carbon sequestration, increase of soil water-holding capacity and pH as well as sorption of different xenobiotics present only a fraction of the multitude of biochar application possibilities. Heavy metals as potential sources of ecotoxicological risks are characterized by their non-degradability and the potential transfer into the food chain. Carbonaceous materials have been used for a long time as sorbents for heavy metals and organic contaminants in soil and water technologies. The similarity of biochar with activated carbon predetermines this material as remediation tool which plays an important role in heavy metal immobilization and retention with a parallel reduction in the risk of ground water and food crop contamination. In all this processes the element-specific sorption behaviour of biochar creates new conditions for pollutant binding. Sorption interaction and separation of contaminants from soil solution or waste effluent can be affected by wide-ranging parameters. In detail, our study was based on batch-sorption comparisons of two biochars produced from wood chips and green waste residues. We observed that sorption efficiency of biochar for model bivalent heavy metals (Cd, Zn, Cu) can be influenced by equilibrium parameters such as pH, contact time, initial concentration of metal in reaction solutions, presence of surfactants and chemical modification by acid hydrolysis, esterification and methylation. The

  1. Ecological risk assessment on heavy metals in soils: Use of soil diffuse reflectance mid-infrared Fourier-transform spectroscopy

    PubMed Central

    Wang, Cheng; Li, Wei; Guo, Mingxing; Ji, Junfeng

    2017-01-01

    The bioavailability of heavy metals in soil is controlled by their concentrations and soil properties. Diffuse reflectance mid-infrared Fourier-transform spectroscopy (DRIFTS) is capable of detecting specific organic and inorganic bonds in metal complexes and minerals and therefore, has been employed to predict soil composition and heavy metal contents. The present study explored the potential of DRIFTS for estimating soil heavy metal bioavailability. Soil and corresponding wheat grain samples from the Yangtze River Delta region were analyzed by DRIFTS and chemical methods. Statistical regression analyses were conducted to correlate the soil spectral information to the concentrations of Cd, Cr, Cu, Zn, Pb, Ni, Hg and Fe in wheat grains. The principal components in the spectra influencing soil heavy metal bioavailability were identified and used in prediction model construction. The established soil DRIFTS-based prediction models were applied to estimate the heavy metal concentrations in wheat grains in the mid-Yangtze River Delta area. The predicted heavy metal concentrations of wheat grain were highly consistent with the measured levels by chemical analysis, showing a significant correlation (r2 > 0.72) with acceptable root mean square error RMSE. In conclusion, DRIFTS is a promising technique for assessing the bioavailability of soil heavy metals and related ecological risk. PMID:28198802

  2. Ecological risk assessment on heavy metals in soils: Use of soil diffuse reflectance mid-infrared Fourier-transform spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Li, Wei; Guo, Mingxing; Ji, Junfeng

    2017-02-01

    The bioavailability of heavy metals in soil is controlled by their concentrations and soil properties. Diffuse reflectance mid-infrared Fourier-transform spectroscopy (DRIFTS) is capable of detecting specific organic and inorganic bonds in metal complexes and minerals and therefore, has been employed to predict soil composition and heavy metal contents. The present study explored the potential of DRIFTS for estimating soil heavy metal bioavailability. Soil and corresponding wheat grain samples from the Yangtze River Delta region were analyzed by DRIFTS and chemical methods. Statistical regression analyses were conducted to correlate the soil spectral information to the concentrations of Cd, Cr, Cu, Zn, Pb, Ni, Hg and Fe in wheat grains. The principal components in the spectra influencing soil heavy metal bioavailability were identified and used in prediction model construction. The established soil DRIFTS-based prediction models were applied to estimate the heavy metal concentrations in wheat grains in the mid-Yangtze River Delta area. The predicted heavy metal concentrations of wheat grain were highly consistent with the measured levels by chemical analysis, showing a significant correlation (r2 > 0.72) with acceptable root mean square error RMSE. In conclusion, DRIFTS is a promising technique for assessing the bioavailability of soil heavy metals and related ecological risk.

  3. Heavy metal accumulation in agricultural soils around a coal fired thermal power plant (Farakka) in India.

    PubMed

    Sengupta, Saswati; Chatterjee, Tamoghno; Ghosh, P B; Saha, Tapan

    2010-10-01

    Agricultural soils around the ash dumping sites of one of the largest thermal power plant (TPP) in India located at Farakka, West Bengal were assessed for some heavy metal (Pb, Cd, Cr, As, Cu, Zn, Ni and Fe) distribution in association with other physicochemical components and compared with the control soils collected from far away of TPP. The toxic group metals (Pb, Cd, Cr and As) were well differentiated by their higher values of variability and non-normal distribution from the biologically essential metals (Cu, Zn, Ni and Fe). The statistical analysis of the heavy metals revealed that the two probable sources (Eigen values) in affected soils are responsible for their distribution; the more dominant one contributed the toxic metals and less dominating source contributed the essential heavy metals. While in control soils, no distinct separation of sources of the metals were found out signifying that the natural common sources could play active role in metal distributions. Although EF (Enrichment Factor) values of toxic metals are higher with large fraction of anthropogenic sources, yet (Igeo) (Geo-accumulation Index) values indicate moderate to unpolluted condition of the soils in respect to Pb, Cd and As. The calculated PLI (Pollution Load Index) values (1.88) considering all the metals also support the findings. Since there are no other sources of industrial effluents in the study area except the TPP, it can be said that the enrichment of these metals is solely attributed to their input from the ash contamination. For this, considerable degree of enrichment of toxic group of metals occurred in these soils.

  4. On final conditions in high energy heavy ion Collisions

    SciTech Connect

    Sinyukov, Yu.M.; Akkelin, S.V.; Xu, N.

    1998-06-01

    Motivated by the recent experimental observations, wediscuss the freeze-out properties of the fireball created in centralheavy ion collisions. We find that the freeze-out conditions, liketemperature, velocity gradient near center of the fireball, are similarfor different colliding systems and beam energies. This means that thetransverse flow is stronger in the collisions of heavy nuclei than thatof the light ones.

  5. A general model for kinetics of heavy metal adsorption and desorption on soils.

    PubMed

    Shi, Zhenqing; Di Toro, Dominic M; Allen, Herbert E; Sparks, Donald L

    2013-04-16

    In this study, we propose a general kinetics model for heavy metal adsorption and desorption reactions in soils when soil organic matter (SOM) is the dominant adsorbent. The kinetics model, integrated with the equilibrium speciation model WHAM VI, specifically considers metal reactions with SOM and dissolved organic matter (DOM) and accounts for the variations of solution chemistry. Metal reactions with SOM are associated with two groups of sites, one from the monodentate sites and another one from the bidentate and tridentate sites. There are three model parameters, desorption rate coefficients of the two groups of SOM sites for each metal and reactive organic carbon (ROC) for each soil. The applicability of the kinetics model was mainly examined with three elements, Cu, Pb, and Zn, which demonstrate different binding ability with organic matter. The kinetic data were collected with a stirred-flow reactor covering a wide range of experimental conditions, including varying SOM, DOM, Ca, and metal concentrations, reaction pHs, and different flow rates. The kinetics model has been successfully applied to describe heavy metal adsorption and desorption on soils under various reaction conditions.

  6. Application of portable XRF and VNIR sensors for rapid assessment of soil heavy metal pollution

    PubMed Central

    Hu, Bifeng; Chen, Songchao; Hu, Jie; Xia, Fang; Xu, Junfeng; Li, Yan; Shi, Zhou

    2017-01-01

    Rapid heavy metal soil surveys at large scale with high sampling density could not be conducted with traditional laboratory physical and chemical analyses because of the high cost, low efficiency and heavy workload involved. This study explored a rapid approach to assess heavy metals contamination in 301 farmland soils from Fuyang in Zhejiang Province, in the southern Yangtze River Delta, China, using portable proximal soil sensors. Portable X-ray fluorescence spectroscopy (PXRF) was used to determine soil heavy metals total concentrations while soil pH was predicted by portable visible-near infrared spectroscopy (PVNIR). Zn, Cu and Pb were successfully predicted by PXRF (R2 >0.90 and RPD >2.50) while As and Ni were predicted with less accuracy (R2 <0.75 and RPD <1.40). The pH values were well predicted by PVNIR. Classification of heavy metals contamination grades in farmland soils was conducted based on previous results; the Kappa coefficient was 0.87, which showed that the combination of PXRF and PVNIR was an effective and rapid method to determine the degree of pollution with soil heavy metals. This study provides a new approach to assess soil heavy metals pollution; this method will facilitate large-scale surveys of soil heavy metal pollution. PMID:28234944

  7. Siderophore production by streptomycetes-stability and alteration of ferrihydroxamates in heavy metal-contaminated soil.

    PubMed

    Schütze, Eileen; Ahmed, Engy; Voit, Annekatrin; Klose, Michael; Greyer, Matthias; Svatoš, Aleš; Merten, Dirk; Roth, Martin; Holmström, Sara J M; Kothe, Erika

    2015-12-01

    Heavy metal-contaminated soil derived from a former uranium mining site in Ronneburg, Germany, was used for sterile mesocosms inoculated with the extremely metal-resistant Streptomyces mirabilis P16B-1 or the sensitive control strain Streptomyces lividans TK24. The production and fate of bacterial hydroxamate siderophores in soil was analyzed, and the presence of ferrioxamines E, B, D, and G was shown. While total ferrioxamine concentrations decreased in water-treated controls after 30 days of incubation, the sustained production by the bacteria was seen. For the individual molecules, alteration between neutral and cationic forms and linearization of hydroxamates was observed for the first time. Mesocosms inoculated with biomass of either strain showed changes of siderophore contents compared with the non-treated control indicating for auto-alteration and consumption, respectively, depending on the vital bacteria present. Heat stability and structural consistency of siderophores obtained from sterile culture filtrate were shown. In addition, low recovery (32 %) from soil was shown, indicating adsorption to soil particles or soil organic matter. Fate and behavior of hydroxamate siderophores in metal-contaminated soils may affect soil properties as well as conditions for its inhabiting (micro)organisms.

  8. Space-time quantitative source apportionment of soil heavy metal concentration increments.

    PubMed

    Yang, Yong; Christakos, George; Guo, Mingwu; Xiao, Lu; Huang, Wei

    2017-04-01

    Assessing the space-time trends and detecting the sources of heavy metal accumulation in soils have important consequences in the prevention and treatment of soil heavy metal pollution. In this study, we collected soil samples in the eastern part of the Qingshan district, Wuhan city, Hubei Province, China, during the period 2010-2014. The Cd, Cu, Pb and Zn concentrations in soils exhibited a significant accumulation during 2010-2014. The spatiotemporal Kriging technique, based on a quantitative characterization of soil heavy metal concentration variations in terms of non-separable variogram models, was employed to estimate the spatiotemporal soil heavy metal distribution in the study region. Our findings showed that the Cd, Cu, and Zn concentrations have an obvious incremental tendency from the southwestern to the central part of the study region. However, the Pb concentrations exhibited an obvious tendency from the northern part to the central part of the region. Then, spatial overlay analysis was used to obtain absolute and relative concentration increments of adjacent 1- or 5-year periods during 2010-2014. The spatial distribution of soil heavy metal concentration increments showed that the larger increments occurred in the center of the study region. Lastly, the principal component analysis combined with the multiple linear regression method were employed to quantify the source apportionment of the soil heavy metal concentration increments in the region. Our results led to the conclusion that the sources of soil heavy metal concentration increments should be ascribed to industry, agriculture and traffic. In particular, 82.5% of soil heavy metal concentration increment during 2010-2014 was ascribed to industrial/agricultural activities sources. Using STK and SOA to obtain the spatial distribution of heavy metal concentration increments in soils. Using PCA-MLR to quantify the source apportionment of soil heavy metal concentration increments. Copyright © 2017

  9. Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

    PubMed

    Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

    2015-12-01

    It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P < 0.05) than farmers irrigating with clean water, but metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

  10. Plasma treatment of INEL soil contaminated with heavy metals

    SciTech Connect

    Detering, B.A.; Batdorf, J.A.

    1992-01-01

    INEL soil spiked with inorganic salts of chromium, lead, mercury, silver, and zinc was melted in a 150 kW plasma furnace to produce a glassy slag product. This glassy slag is an environmentally safe waste form. In order to reduce the melting temperature of the soil, sodium carbonate was added to half of the test batches. Random sample from each batch of glassy slag product were analyzed by an independent laboratory for total metals concentration and leachability of metals via the Environmental Protection Agency (EPA) toxicity characterization leaching procedure (RCLP) tests. These tests showed the residual metals were very tightly bound to the slag matrix and were within EPA TCLP limits under these test conditions. Additionally, scanning electron microscopy (SEM) and emissions dispersive spectroscopy (EDS) analysis of the vitrified soil also confirmed that the added metals present in the vitrified soil were totally contained in the crystalline phase as distinct oxide crystallites.

  11. Analytical techniques for estimation of heavy metals in soil ecosystem: a tabulated review.

    PubMed

    Soodan, Rajneet Kour; Pakade, Yogesh B; Nagpal, Avinash; Katnoria, Jatinder Kaur

    2014-07-01

    Soil, an important environmental medium, is exposed to a number of pollutants including toxic heavy metals by various natural and anthropogenic activities. Consequently heavy metal contaminated soil has the potential to pose severe health risks and hazards to humans as well as other living creatures of the ecosystem through various routes of exposure such as direct ingestion, contaminated drinking ground water, food crops, contact with contaminated soil and through food chain. Therefore, it is mandatory to explore various techniques that could efficiently determine the occurrence of heavy metals in soil. A number of methods have been developed by several regulatory agencies and private laboratories and are applied routinely for the quantification and monitoring of soil matrices. The present review is an initiative to summarize the work on pollution levels of soil ecosystem and thus pertains to various extraction and quantification procedures used worldwide to analyze heavy metals in soil.

  12. Analysis of heavy metal sources in soil using kriging interpolation on principal components.

    PubMed

    Ha, Hoehun; Olson, James R; Bian, Ling; Rogerson, Peter A

    2014-05-06

    Anniston, Alabama has a long history of operation of foundries and other heavy industry. We assessed the extent of heavy metal contamination in soils by determining the concentrations of 11 heavy metals (Pb, As, Cd, Cr, Co, Cu, Mn, Hg, Ni, V, and Zn) based on 2046 soil samples collected from 595 industrial and residential sites. Principal Component Analysis (PCA) was adopted to characterize the distribution of heavy metals in soil in this region. In addition, a geostatistical technique (kriging) was used to create regional distribution maps for the interpolation of nonpoint sources of heavy metal contamination using geographical information system (GIS) techniques. There were significant differences found between sampling zones in the concentrations of heavy metals, with the exception of the levels of Ni. Three main components explaining the heavy metal variability in soils were identified. The results suggest that Pb, Cd, Cu, and Zn were associated with anthropogenic activities, such as the operations of some foundries and major railroads, which released these heavy metals, whereas the presence of Co, Mn, and V were controlled by natural sources, such as soil texture, pedogenesis, and soil hydrology. In general terms, the soil levels of heavy metals analyzed in this study were higher than those reported in previous studies in other industrial and residential communities.

  13. Assessing phytotoxicity of heavy metals in remediated soil.

    PubMed

    Branzini, A; Zubillaga, M S

    2010-01-01

    Copper (Cu), zinc (Zn) and chromium (Cr) are pollutants that usually are accumulated in soils. Their toxicity can be decreased by applying amendments. We proposed to evaluate changes in Cu, Zn, and Cr availability, due to the application of amendments, through chemical analysis and phytotoxicity tests. The phytotoxicity test was carried out using species belonging to Sesbania genus; plant parameters were measured 48, 72, 96, and 168 hours after the start of incubation. The treatments included enriched soil, in addition to biosolid compost and triple superphosphate. Cu and Zn amounts were higher in treatments without amendments, indicating immobilization on the part of these. The amounts of Cr tended to decrease with amendments application. The amendments increased pH values and decreased EC; however, this had no impact on the results. No relationship was found among pH, EC, and plant parameters. Different behaviors were observed. S. virgata showed germination seed delay. In addition, while in S. virgata the IG increased during the assay, in S. punicea it diminished. The application of compost, fertilizer or both combined could be of interest for contaminated soils remediation. The use of chemical analysis and phytotoxicity tests allowed to estimate heavy metal availability and the effect on both Sesbania species.

  14. Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).

    PubMed

    Lu, Mang; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Min; Xu, Yu-Xin; Wu, Xue-Jiao

    2014-01-21

    90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil.

  15. Remediation of soil co-contaminated with petroleum and heavy metals by the integration of electrokinetics and biostimulation.

    PubMed

    Dong, Zhi-Yong; Huang, Wen-Hui; Xing, Ding-Feng; Zhang, Hong-Feng

    2013-09-15

    Successful remediation of soil co-contaminated with high levels of organics and heavy metals is a challenging task, because that metal pollutants in soil can partially or completely suppress normal heterotrophic microbial activity and thus hamper biodegradation of organics. In this study, the benefits of integrating electrokinetic (EK) remediation with biodegradation for decontaminating soil co-contaminated with crude oil and Pb were evaluated in laboratory-scale experiments lasting for 30 days. The treated soil contained 12,500 mg/kg of total petroleum hydrocarbons (TPH) and 450 mg/kg Pb. The amendments of EDTA and Tween 80, together with a regular refreshing of electrolyte showed the best performance to remediate this contaminated soil. An important function of EDTA-enhanced EK treatment was to eliminate heavy metal toxicity from the soil, thus activating microbial degradation of oil. Although Tween 80 reduced current, it could serve as a second substrate for enhancing microbial growth and biodegradation. It was found that oil biodegradation degree and microbial numbers increased toward the anode and cathode. Microbial metabolism was found to be beneficial to metal release from the soil matrix. Under the optimum conditions, the soil Pb and TPH removal percentages after 30 days of running reached 81.7% and 88.3%, respectively. After treatment, both the residual soil Pb and TPH concentrations met the requirement of the Chinese soil environmental quality standards. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Determination of heavy metals in soil and different parts of Diplazium esculentum (medicinal fern)

    NASA Astrophysics Data System (ADS)

    Jasim, Hind S.; Idris, Mushrifah; Abdullah, Aminah; Kadhum, A. A. H.

    2014-09-01

    Diplazium esculentum is a widely used medicinal fern in Malaysia and other regions worldwide. Heavy metals in plants should be determined because prolonged human intake of toxic trace elements, even at low doses, results in organ malfunction and causes chronic toxicity. Hence, substantial information should be obtained from plants that grow on soils containing high concentrations of heavy metals. This study aimed to determine the physicochemical characteristics of soil and heavy metal concentrations (Pb, Cr, Mn, Cu, and Zn) in different parts of D. esculentum and soil, which were collected from the fern garden of Universiti Kebangsaan Malaysia. Results showed that heavy metals were highly accumulated in D. esculentum roots.

  17. [Investigation and analysis of heavy metal pollution related to soil-Panax notoginseng system].

    PubMed

    Chen, Lu; Mi, Yan-Hua; Lin, Xin; Liu, Da-Hui; Zeng, Min; Chen, Xiao-Yan

    2014-07-01

    In this study, five heavy metals contamination of soil and different parts of Panax notoginseng in the plantation area was investigated. Analysis of heavy metals correlation between the planting soil and P. notoginseng; and the absorption and accumulation characteristics and translocation of soil heavy metals by P. notoginseng plants was revealed. Through field investigation and laboratory analytical methods, analysis of China's 30 different soil P. notoginseng origin and content of heavy metals in five different parts of the P. notoginseng plant content of heavy metals. The results revealed that the soil heavy metals should not be neglected in the plantation area Referring to the national soil quality standards (GB15608-1995), the excessive degree of soil heavy metals pollution showed Hg > As > Cd > Cr in the plantation area, and Pb content of soil was in the scope of the standard. Refer to 'Green Industry Standards for Import and Export of Medical Plants and Preparations', the excessive degree of heavy metals content of P. notoginseng plants showed As > Pb > Cr > Cd, and Hg content of plants was in the scope of the standard. Concentrations of five heavy metals of underground parts of P. notoginseng plants are higher than aboveground, and heavy metals elements are more concentrated in the root, followed by the rhizome of P. notoginseng plants. Heavy metal accumulation characteristics of the different parts of the P. notoginseng of the overall performance is the root > the rhizome > the root tuber > leaves > stems. From the point of view BCF value analysis of various parts of the P. notoginseng plants to absorb heavy metals in soil, BCF values of all samples were less than 1, description P. notoginseng not belong Hyperaccumulator. From the view of transportation and related analysis of the soil-P. notoginseng systems, the rhizome of P. notoginseng and the content of As and Cr in soil was significantly correlated, the root of P. notoginseng and the content of Cd in

  18. Fractionation behavior of heavy metals in soil during bioleaching with Acidithiobacillus thiooxidans.

    PubMed

    Naresh Kumar, R; Nagendran, R

    2009-09-30

    The effects of bioleaching on the fractionation of soil heavy metals were investigated in this study. Bioleaching of heavy metals from contaminated soil was carried out in shake flask experiments. Acidophilic sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from soil was used for bioleaching. Bioleaching resulted in removal of heavy metals at higher levels. Variations in the binding forms of heavy metals before, during and after bioleaching were evaluated. It was noticed that bioleaching affected the binding forms of all the heavy metals present in the soil. The major contaminant chromium bound mainly to the fractions of soil which are not very reactive (organic and residual fractions) also showed good removal efficiency. Bioleaching influenced the fractionation of metals in soil after treatment and most of the remnant heavy metals were bound either to residual fraction or to other not easily mobile fractions of soil. The results of this study indicated that the bioleaching process can be useful for efficient removal of heavy metals from soil. Further, the soil with remnant metals can be disposed off safely.

  19. Atmospheric Deposition of Heavy Metals in Soil Affected by Different Soil Uses of Southern Spain

    NASA Astrophysics Data System (ADS)

    Acosta, J. A.; Faz, A.; Martínez-Martínez, S.; Bech, J.

    2009-04-01

    Heavy metals are a natural constituent of rocks, sediments and soils. However, the heavy metal content of top soils is also dependent on other sources than weathering of the indigenous minerals; input from atmospheric deposition seems to be an important pathway. Atmospheric deposition is defined as the process by which atmospheric pollutants are transferred to terrestrial and aquatic surfaces and is commonly classified as either dry or wet. The interest in atmospheric deposition has increased over the past decade due to concerns about the effects of deposited materials on the environment. Dry deposition provides a significant mechanism for the removal of particles from the atmosphere and is an important pathway for the loading of heavy metals into the soil ecosystem. Within the last decade, an intensive effort has been made to determine the atmospheric heavy metal deposition in both urban and rural areas. The main objective of this study was to identification of atmospheric heavy metals deposition in soil affected by different soil uses. Study area is located in Murcia Province (southeast of Spain), in the surroundings of Murcia City. The climate is typically semiarid Mediterranean with an annual average temperature of 18°C and precipitation of 350 mm. In order to determine heavy metals atmospheric deposition a sampling at different depths (0-1 cm, 1-5 cm, 5-15 cm and 15-30 cm) was carried out in 7 sites including agricultural soils, two industrial areas and natural sites. The samples were taken to the laboratory where, dried, passed through a 2 mm sieve, and grinded. For the determination of the moisture the samples were weighed and oven dried at 105 °C for 24 h. The total amounts of metals (Pb, Cu, Pb, Zn, Cd, Mn, Ni and Cr) were determined by digesting the samples with nitric/perchoric acids and measuring with ICP-MS. Results showed that zinc contamination in some samples of industrial areas was detected, even this contamination reaches 30 cm depth; thus it is

  20. Model for the study of the impact of atmospheric heavy metals on soil microbial biomass.

    PubMed

    Marchionni, M; Benedetti, A; Riccardi, C; Villarini, M

    2000-01-01

    In the Castelporziano (Rome) protected area the inputs of atmospheric heavy metals on the soil-plant system were evaluated by the analysis of stem-flowing water from Quercus ilex L. The heavy metals detected in the soil under the canopies exhibited higher concentrations near to the tree trunks, highlighting the tree's capacity to concentrate such polluting substances. Microbial biomass, its specific respiration and the biomass calculated as a percentage of total soil organic matter, were utilised as indicators of the state of the soil and consequently also its quality with respect to heavy metal contamination.

  1. Effects of natural factors on the spatial distribution of heavy metals in soils surrounding mining regions.

    PubMed

    Ding, Qian; Cheng, Gong; Wang, Yong; Zhuang, Dafang

    2017-02-01

    Various studies have shown that soils surrounding mining areas are seriously polluted with heavy metals. Determining the effects of natural factors on spatial distribution of heavy metals is important for determining the distribution characteristics of heavy metals in soils. In this study, an 8km buffer zone surrounding a typical non-ferrous metal mine in Suxian District of Hunan Province, China, was selected as the study area, and statistical, spatial autocorrelation and spatial interpolation analyses were used to obtain descriptive statistics and spatial autocorrelation characteristics of As, Pb, Cu, and Zn in soil. Additionally, the distributions of soil heavy metals under the influences of natural factors, including terrain (elevation and slope), wind direction and distance from a river, were determined. Layout of sampling sites, spatial changes of heavy metal contents at high elevations and concentration differences between upwind and downwind directions were then evaluated. The following results were obtained: (1) At low elevations, heavy metal concentrations decreased slightly, then increased considerably with increasing elevation. At high elevations, heavy metal concentrations first decreased, then increased, then decreased with increasing elevation. As the slope increased, heavy metal contents increased then decreased. (2) Heavy metal contents changed consistently in the upwind and downwind directions. Heavy metal contents were highest in 1km buffer zone and decreased with increasing distance from the mining area. The largest decrease in heavy metal concentrations was in 2km buffer zone. Perennial wind promotes the transport of heavy metals in downwind direction. (3) The spatial extent of the influence of the river on Pb, Zn and Cu in the soil was 800m. (4) The influence of the terrain on the heavy metal concentrations was greater than that of the wind. These results provide a scientific basis for preventing and mitigating heavy metal soil pollution in

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

    PubMed

    Kim, Kwon-Rae; Owens, Gary

    2009-01-01

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

  3. Diversity of arbuscular mycorrhizal fungus populations in heavy-metal-contaminated soils

    SciTech Connect

    Del Val, C.; Barea, J.M.; Azcon-Aguilar, C.

    1999-02-01

    High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. The authors conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils.

  4. [Heavy metal pollution characteristics and ecological risk analysis for soil around Haining electroplating industrial park].

    PubMed

    Li, Jiong-Hui; Weng, Shan; Fang, Jing; Huang, Jia-Lei; Lu, Fang-Hua; Lu, Yu-Hao; Zhang, Hong-Ming

    2014-04-01

    The pollution status and potential ecological risks of heavy metal in soils around Haining electroplating industrial park were studied. Hakanson index approach was used to assess the ecological hazards of heavy metals in soils. Results showed that average concentrations of six heavy metals (Cu, Ni, Pb, Zn, Cd and Cr) in the soils were lower than the secondary criteria of environmental quality standard for soils, indicating limited harmful effects on the plants and the environment in general. Though the average soil concentrations were low, heavy metal concentrations in six sampling points located at the side of road still exceeded the criteria, with excessive rate of 13%. Statistic analysis showed that concentrations of Cu and Cd in roadside soils were significantly higher than those in non-roadside soils, indicating that the excessive heavy metal accumulations in the soil closely related with traffic transport. The average potential ecological hazard index of soils around Haining electroplating industrial park was 46.6, suggesting a slightly ecological harm. However, the potential ecological hazard index of soils with excessive heavy metals was 220-278, suggesting the medium ecological hazards. Cd was the most seriously ecological hazard factor.

  5. Diversity of arbuscular mycorrhizal fungus populations in heavy-metal-contaminated soils.

    PubMed

    Del Val, C; Barea, J M; Azcón-Aguilar, C

    1999-02-01

    High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. We conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils.

  6. Diversity of Arbuscular Mycorrhizal Fungus Populations in Heavy-Metal-Contaminated Soils

    PubMed Central

    Del Val, C.; Barea, J. M.; Azcón-Aguilar, C.

    1999-01-01

    High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. We conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils. PMID:9925606

  7. [Evaluation on environmental quality of heavy metals in soils and vegetables based on geostatistics and GIS].

    PubMed

    Xie, Zheng-miao; Li, Jing; Wang, Bi-ling; Chen, Jian-jun

    2006-10-01

    Contents of heavy metals (Pb, Zn, Cd, Cu) in soils and vegetables from Dongguan town in Shangyu city, China were studied using geostatistical analysis and GIS technique to evaluate environmental quality. Based on the evaluation criteria, the distribution of the spatial variability of heavy metals in soil-vegetable system was mapped and analyzed. The results showed that the distribution of soil heavy metals in a large number of soil samples in Dongguan town was asymmetric. The contents of Zn and Cu were lower than those of Cd and Pb. The concentrations distribution of Pb, Zn, Cd and Cu in soils and vegetables were different in spatial variability. There was a close relationship between total and available contents of heavy metals in soil. The contents of Pb and Cd in green vegetables were higher than those of Zn and Cu and exceeded the national sanitation standards for vegetables.

  8. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    PubMed Central

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

  9. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    PubMed

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-12-22

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety.

  10. Effects of aerobic and anaerobic biological processes on leaching of heavy metals from soil amended with sewage sludge compost.

    PubMed

    Fang, Wen; Wei, Yonghong; Liu, Jianguo; Kosson, David S; van der Sloot, Hans A; Zhang, Peng

    2016-12-01

    The risk from leaching of heavy metals is a major factor hindering land application of sewage sludge compost (SSC). Understanding the change in heavy metal leaching resulting from soil biological processes provides important information for assessing long-term behavior of heavy metals in the compost amended soil. In this paper, 180days aerobic incubation and 240days anaerobic incubation were conducted to investigate the effects of the aerobic and anaerobic biological processes on heavy metal leaching from soil amended with SSC, combined with chemical speciation modeling. Results showed that leaching concentrations of heavy metals at natural pH were similar before and after biological process. However, the major processes controlling heavy metals were influenced by the decrease of DOC with organic matter mineralization during biological processes. Mineralization of organic matter lowered the contribution of DOC-complexation to Ni and Zn leaching. Besides, the reducing condition produced by biological processes, particularly by the anaerobic biological process, resulted in the loss of sorption sites for As on Fe hydroxide, which increased the potential risk of As release at alkaline pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Heavy Metals in Water Percolating Through Soil Fertilized with Biodegradable Waste Materials.

    PubMed

    Wierzbowska, Jadwiga; Sienkiewicz, Stanisław; Krzebietke, Sławomir; Bowszys, Teresa

    2016-01-01

    The influence of manure and composts on the leaching of heavy metals from soil was evaluated in a model lysimeter experiment under controlled conditions. Soil samples were collected from experimental fields, from 0- to 90-cm layers retaining the layout of the soil profile layers, after the second crop rotation cycle with the following plant species: potatoes, spring barley, winter rapeseed, and winter wheat. During the field experiment, 20 t DM/ha of manure, municipal sewage sludge composted with straw (SSCS), composted sewage sludge (SSC), dried granular sewage sludge (DGSS), "Dano" compost made from non-segregated municipal waste (CMMW), and compost made from municipal green waste (CUGW) was applied, i.e., 10 t DM/ha per crop rotation cycle. The concentrations (μg/dm(3)) of heavy metals in the leachate were as follows: Cd (3.6-11.5) < Mn (4.8-15.4) < Cu (13.4-35.5) < Zn (27.5-48.0) < Cr (36.7-96.5) < Ni (24.4-165.8) < Pb (113.8-187.7). Soil fertilization with organic waste materials did not contaminate the percolating water with manganese or zinc, whereas the concentrations of the other metals increased to the levels characteristic of unsatisfactory water quality and poor water quality classes. The copper and nickel content of percolating water depended on the concentration of those metals introduced into the soil with organic waste materials. The concentrations of Cd in the leachate increased, whereas the concentrations of Cu and Ni decreased with increasing organic C content of organic fertilizers. The widening of the C/N ratio contributed to Mn leaching. The concentrations of Pb, Cr, and Mn in the percolating water were positively correlated with the organic C content of soil.

  12. Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

    SciTech Connect

    Teresa W.-M. Fan; Richard M. Higashi; David Crowley; Andrew N. Lane: Teresa A. Cassel; Peter G. Green

    2004-12-31

    For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.

  13. Measuring the hydraulic conductivity of soil adjacent to tile drains in a heavy clay soil in The Netherlands

    NASA Astrophysics Data System (ADS)

    Bouma, J.; Van Hoorn, J. W.; Stoffelsen, G. H.

    The hydraulic conductivity, Ksat, of soil adjacent to tile drains in heavy clay soils was measured at twelve locations with a new technique. This technique involves excavation of a cube of soil (25 cm × 25 cm × 25 cm) in situ around a tile fragment. Cutting of the tile leaves it protruding from the cube for ˜5 cm on two sides, also when covering five sides of the cube with a layer of gypsum outside the pit. Flow rates from the tile are measured for two conditions: (1) infiltration into the layer which was previously the lower horizontal soil surface of the cube; and (2) infiltration into the upper surface. The cube is turned upside down to allow the first measurement. The open surface is then covered with gypsum. The cube is turned upside down again and gypsum is removed from the upper surface of the cube (which is the original upper surface of the cube in the pit) to allow the second measurement. The first measurement mainly characterizes undisturbed soil below the drain, the second characterizes soil above the drain (fill). Dye is added to the percolating water to trace patterns of water movement, using micromorphometric techniques. Flow rates are transformed to Ksat-values by using an electrolytic analog model. Measured Ksat-values below the drain had median values of 10 m/day and agreed well with those measured in undisturbed soil at comparable depth, indicating that there are no changes due to either system construction or system operation. The median Ksat for fill above the drain was 5 m/day. The conclusions reached pertain to three types of drains, e.g., one fired-clay pipe and two types of plastic pipe. The dye studies showed that water movement occurred almost exclusively along larger planar voids (cracks), and hardly along channels (rootholes). Water-conducting voids were below 2% by volume.

  14. Soil metatranscriptomics for mining eukaryotic heavy metal resistance genes.

    PubMed

    Lehembre, Frédéric; Doillon, Didier; David, Elise; Perrotto, Sandrine; Baude, Jessica; Foulon, Julie; Harfouche, Lamia; Vallon, Laurent; Poulain, Julie; Da Silva, Corinne; Wincker, Patrick; Oger-Desfeux, Christine; Richaud, Pierre; Colpaert, Jan V; Chalot, Michel; Fraissinet-Tachet, Laurence; Blaudez, Damien; Marmeisse, Roland

    2013-10-01

    Heavy metals are pollutants which affect all organisms. Since a small number of eukaryotes have been investigated with respect to metal resistance, we hypothesize that many genes that control this phenomenon remain to be identified. This was tested by screening soil eukaryotic metatranscriptomes which encompass RNA from organisms belonging to the main eukaryotic phyla. Soil-extracted polyadenylated mRNAs were converted into cDNAs and 35 of them were selected for their ability to rescue the metal (Cd or Zn) sensitive phenotype of yeast mutants. Few of the genes belonged to families known to confer metal resistance when overexpressed in yeast. Several of them were homologous to genes that had not been studied in the context of metal resistance. For instance, the BOLA ones, which conferred cross metal (Zn, Co, Cd, Mn) resistance may act by interfering with Fe homeostasis. Other genes, such as those encoding 110- to 130-amino-acid-long, cysteine-rich polypeptides, had no homologues in databases. This study confirms that functional metatranscriptomics represents a powerful approach to address basic biological processes in eukaryotes. The selected genes can be used to probe new pathways involved in metal homeostasis and to manipulate the resistance level of selected organisms. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  15. Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils

    PubMed Central

    Chen, Qun; Wang, Shujuan; Li, Yan; Zhang, Ning; Zhao, Bo; Zhuo, Yuqun; Chen, Changhe

    2015-01-01

    Abstract Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline–alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation. PMID:26064038

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

    A multitude of research investigations have confirmed that biochars can increase soil carbon sequestration, improve critical plant nutrient concentrations, and improve the fertility, chemical, and physical properties of degraded agricultural soils. Recently, biochars ability to sequester metals has caught the attention of the mine reclamation sector. It is proposed that biochar is a suitable amendment to remediate heavy metals in mine spoils, as well as improve chemical conditions for enhanced plant growth. Better plant growth will improve phytostabilization, increase containment of metal-laden sediment, while also reducing potential metal uptake by plants. As such, utilization of a biochar with appropriate chemical and physical characteristics is crucial for effective binding of heavy metals while also improving plant growth conditions in mine spoils. Using two different mine spoils, we conducted laboratory and greenhouse experiments to determine the ability of designer biochar with or without lime application to favorably improve soil pH, reduce heavy metal bioavailability, and improve grass (e.g., wild blue rye) plant nutrient uptake. Preliminary results showed that our designer biochars did increase pH of acid mine spoils significantly (p<0.001), improved uptake of critical plant nutrients (e.g., phosphorus, potassium and calcium), and significantly (p<0.001) reduced the concentrations of heavy metals (e.g. aluminum, chromium, zinc, nickel, zinc, manganese, copper and cadmium) in the soils.

  17. Progress in the remediation of hazardous heavy metal-polluted soils by natural zeolite.

    PubMed

    Shi, Wei-yu; Shao, Hong-bo; Li, Hua; Shao, Ming-an; Du, Sheng

    2009-10-15

    Hazardous heavy metal pollution of soils is an increasingly urgent problem all over the world. The zeolite as a natural amendment has been studied extensively for the remediation of hazardous heavy metal-polluted soils with recycling. But its theory and application dose are not fully clear. This paper reviews the related aspects of theory and application progress for the remediation of hazardous heavy metal-polluted soils by natural zeolite, with special emphasis on single/co-remediation. Based on the comments on hazardous heavy metal behavior characteristics in leaching and rhizosphere and remediation with zeolite for heavy metal-polluted soils, it indicated that the research of rhizosphere should be strengthened. Theory of remediation with natural zeolite could make breakthroughs due to the investigation on synthetic zeolite. Co-remediation with natural zeolite may be applied and studied with more prospect and sustainable recycling.

  18. [Characteristics of heavy metal pollution in soil and dust of urban parks in Shanghai].

    PubMed

    Shi, Gui-Tao; Chen, Zhen-Lou; Xu, Shi-Yuan; Wang, Li; Zhang, Ju; Li, Hai-Wen; Li, Li-Na

    2007-02-01

    The contents of heavy metals in soils and dust of urban parks in Shanghai were studied, and the spatial distribution of heavy metals was also analyzed. The results showed that the average contents of Pb (55.06 mg x kg(-1)), Zn(198.54 mg x kg(-1)), Cu(44.57 mg x kg(-1)), Cr (77.01 mg x kg(-1)), Cd (0.40 mg x kg(-1)) and Ni (31.17 mg x kg(-1)) in soils were lower than them in the dust, which were 416.63 mg x kg(-1), 906.29 mg x kg(-1), 235.89 mg x kg(-1), 162.59 mg x kg(-1), 1.58 mg x kg(-1) and 92.19 mg x kg(-1) respectively. The heavy metals in soils except Ni and all the six heavy metals in dust were higher than the background values in Shanghai more or less. The heavy metals average contents in dust in the parks of city central area were lower than them in the parks of city surrounding area, and the heavy metals in soils have similar spatial distribution patterns except for Zn. However, in different districts, the distribution of heavy metals in the soils and dust were not regular. Pearson correlative analysis and principal component analysis indicated that the heavy meals accumulation of the soils and dust were induced by anthropogenic input, furthermore traffic and industry were the main pollution sources.

  19. Isolation and characterization of a heavy metal-resistant Burkholderia sp. from heavy metal-contaminated paddy field soil and its potential in promoting plant growth and heavy metal accumulation in metal-polluted soil.

    PubMed

    Jiang, Chun-yu; Sheng, Xia-fang; Qian, Meng; Wang, Qing-ya

    2008-05-01

    A heavy metal-resistant bacterial strain was isolated from heavy metal-contaminated soils and identified as Burkholderia sp. J62 based on the 16S rDNA gene sequence analysis. The heavy metal- and antibiotic resistance, heavy metal solubilization of the isolate were investigated. The isolate was also evaluated for promoting plant growth and Pb and Cd uptakes of the plants from heavy metal-contaminated soils in pot experiments. The isolate was found to exhibit different multiple heavy metal and antibiotic resistance characteristics. Atomic absorption spectrometer analysis showed increased bacterial solubilization of lead and cadmium in solution culture and in soils. The isolate produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. The isolate also solubilized inorganic phosphate. Inoculation with the isolate was found to significantly (p<0.05) increase the biomass of maize and tomato plants. Increase in tissue Pb and Cd contents varied from 38% to 192% and from 5% to 191% in inoculated plants growing in heavy metal-contaminated soils compared to the uninoculated control, respectively. These results show that heavy metal-solubilizing and plant growth promoting bacteria are important for plant growth and heavy metal uptake which may provide a new microbial enhanced-phytoremediation of metal-polluted soils.

  20. Understanding molecular mechanisms for improving phytoremediation of heavy metal-contaminated soils.

    PubMed

    Hong-Bo, Shao; Li-Ye, Chu; Cheng-Jiang, Ruan; Hua, Li; Dong-Gang, Guo; Wei-Xiang, Li

    2010-03-01

    Heavy metal pollution of soil is a significant environmental problem with a negative potential impact on human health and agriculture. Rhizosphere, as an important interface of soil and plants, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria or mycorrhizas have received more and more attention. In addition, some plants possess a range of potential mechanisms that may be involved in the detoxification of heavy metals, and they manage to survive under metal stresses. High tolerance to heavy metal toxicity could rely either on reduced uptake or increased plant internal sequestration, which is manifested by an interaction between a genotype and its environment.A coordinated network of molecular processes provides plants with multiple metal-detoxifying mechanisms and repair capabilities. The growing application of molecular genetic technologies has led to an increased understanding of mechanisms of heavy metal tolerance/accumulation in plants and, subsequently, many transgenic plants with increased heavy metal resistance, as well as increased uptake of heavy metals, have been developed for the purpose of phytoremediation. This article reviews advantages, possible mechanisms, current status and future direction of phytoremediation for heavy-metal-contaminated soils.

  1. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p < 0.01) higher in mine affected soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals.

  2. Multivariate-Statistical Assessment of Heavy Metals for Agricultural Soils in Northern China

    PubMed Central

    Yang, Pingguo; Yang, Miao; Mao, Renzhao; Shao, Hongbo

    2014-01-01

    The study evaluated eight heavy metals content and soil pollution from agricultural soils in northern China. Multivariate and geostatistical analysis approaches were used to determine the anthropogenic and natural contribution of soil heavy metal concentrations. Single pollution index and integrated pollution index could be used to evaluate soil heavy metal risk. The results show that the first factor explains 27.3% of the eight soil heavy metals with strong positive loadings on Cu, Zn, and Cd, which indicates that Cu, Zn, and Cd are associated with and controlled by anthropic activities. The average value of heavy metal is lower than the second grade standard values of soil environmental quality standards in China. Single pollution index is lower than 1, and the Nemerow integrated pollution index is 0.305, which means that study area has not been polluted. The semivariograms of soil heavy metal single pollution index fitted spherical and exponential models. The variable ratio of single pollution index showed moderately spatial dependence. Heavy metal contents showed relative safety in the study area. PMID:24892058

  3. Effects of drip irrigation on migration and distribution of heavy metals in soil profile.

    PubMed

    Wei, Binggan; Yu, Jiangping; Dong, Yunshe; Yang, Linsheng; Wang, Jing; Xue, Yuan; Guo, Shufang

    2016-02-01

    Drip irrigation systems have been widely applied in semiarid and arid regions of China. However, little is known about the migration of heavy metals in cultivated soil under drip irrigation. Therefore, the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in soil were determined. The mean contents of Cd, Cr, Cu, Pb, Zn, and Ni in surface soil subjected to irrigation with low and high amounts of water (W1 and W2) were 0.11, 117.50, 37.51, 13.53, 78.10, and 38.41 mg/kg and 0.20, 94.45, 29.71, 22.48, 63.00, and 36.62 mg/kg, respectively. Metal concentrations in deep soil varied slightly between W1 and W2. Among different distances from the dropper, the metal levels in surface soil varied widely, while they varied slightly in deep soil. The Igeo (geo-accumulation index) values indicated that the soil was usually contaminated by Cr, Cu, and Cd. Under W1, Cd and Cu usually accumulated in surface soil near the dropper, while the other metals leached into subsurface soil. Moreover, the metals generally accumulated in soil away from the dropper. However, significant leaching of metals to the subsurface and deep soil was observed near the dropper under W2. Away from the dropper, Cd, Cr, Cu, Ni, and Pb usually accumulated in surface and deep soil. This suggested that heavy metals generally migrated to the soil away from the dropper when subjected to lower amounts of irrigation, while metals usually moved to surface soil and deep soil under high irrigation amounts. These findings indicate that drip irrigation greatly affected the distribution and migration of heavy metals in soil, with irrigation with lower amounts of irrigation water significantly affecting the horizontal migration of heavy metals and higher amounts influencing the vertical movement of heavy metals.

  4. Soil heavy metal contamination in an industrial area: analysis of the data collected during a decade.

    PubMed

    D'Emilio, Mariagrazia; Caggiano, Rosa; Macchiato, Maria; Ragosta, Maria; Sabia, Serena

    2013-07-01

    Soil contamination by heavy metals has become a serious problem mainly because, above certain concentrations, all metals have adverse effects on human health. In particular, the accumulation of heavy metals in agricultural soils leads to elevated uptake by crops and affects food quality and safety. In this paper, we present the results of a study carried out over a decade for evaluating the impact of a new industrial settlement in an area geared to agriculture and livestock and far from urban sites. We focus our study on the bioavailable fraction of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in soil samples. Heavy metal concentrations in soil are analysed with both univariate and multivariate statistical procedures. The main goal of this paper is the development of a statistical procedure, based on a mix of multivariate analysis, able to compare field surveys carried out during different years and to characterize spatial and temporal changes in soil heavy metals concentrations.

  5. Factors of the accumulation of heavy metals and metalloids at geochemical barriers in urban soils

    NASA Astrophysics Data System (ADS)

    Kosheleva, N. E.; Kasimov, N. S.; Vlasov, D. V.

    2015-05-01

    The bulk contents and concentrations of mobile (extracted by an ammonium acetate buffer with EDTA) Cd, Pb, Sb, As, Bi, Zn, and Cu were determined in the surface horizons of urban soils in the Eastern administrative okrug of Moscow. The regression analysis showed that the accumulation of these metals and metalloids in the soils is controlled by the physicochemical soil properties and by number of anthropogenic factors and landscape conditions (geochemical position, type of loose deposits, character of land use, dust load, vehicle emissions, building pattern, percent of green areas, and the extent of sealed soils). The precipitation of studied elements on the geochemical barriers had the following regularities: Cd, Cu, and Zn accumulated on the alkaline barriers; Bi, Sb, As, Cu, Pb, and Zn, on chemisorption barriers; Sb, As, and Pb, on organomineral barriers; and Cd and Cu, on the sorption-sedimentation barriers. Technogenic transformation of the physicochemical properties of urban soils resulted in the increase of the mean bulk contents of heavy metals and metalloids by 33-99%; the portion of elements fixed on the geochemical barriers increased by 26-50%.

  6. Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium

    SciTech Connect

    Senesi, G.S.; De Giacomo, A.; Zaccone, C.

    2009-05-15

    Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation

  7. Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium.

    PubMed

    Senesi, G S; Dell'Aglio, M; Gaudiuso, R; De Giacomo, A; Zaccone, C; De Pascale, O; Miano, T M; Capitelli, M

    2009-05-01

    Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation

  8. Comparative characterization of sewage sludge compost and soil: Heavy metal leaching characteristics.

    PubMed

    Fang, Wen; Wei, Yonghong; Liu, Jianguo

    2016-06-05

    The leaching and accumulation of heavy metals are major concerns following the land application of sewage sludge compost (SSC). We comparatively characterized SSC, the reference soil, and the SSC amended soil to investigate their similarities and differences regarding heavy metal leaching behavior and then to evaluate the effect of SSC land application on the leaching behavior of soil. Results showed that organic matter, including both of particulate organic matter (POM) and dissolved organic matter (DOM), were critical factors influencing heavy metal leaching from both of SSC and the soil. When SSC was applied to soil at the application rate of 48t/ha, the increase of DOM content slightly enhanced heavy metal leaching from the amended soil over the applicable pH domain (6heavy metals. The geochemical speciation modeling revealed that heavy metal speciation in the solid phase were similar between the reference soil and the amended soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. [Effects of heavy machinery operation on the structural characters of cultivated soils in black soil region of Northeast China].

    PubMed

    Wang, En-Heng; Chai, Ya-Fan; Chen, Xiang-Wei

    2008-02-01

    With the cultivated soils in black soil region of Northeast China as test objects, this paper measured their structural characters such as soil strength, bulk density, and non-capillary porosity/capillary porosity (NCP/CP) ratio before and after heavy and medium-sized machinery operation, aimed to study the effects of machinery operation on the physical properties of test soils. The results showed that after machinery operation, there existed three distinct layers from top to bottom in the soil profiles, i.e., plowed layer, cumulative compacted layer, and non-affected layer, according to the changes of soil strength. Under medium-sized machinery operation, these three layers were shallower, and there was a new plow pan at the depth between 17.5 and 30 cm. Heavy machinery operation had significant positive effects on the improvement of topsoil structure (P < 0.05). After subsoiling and harvesting with heavy machinery, the bulk density of topsoil decreased by 7.2% and 3.5%, respectively, and NCP/CP increased by 556.6% after subsoiling, which would benefit water infiltration, reinforce water storage, and weaken the threat of soil erosion. The main action of heavy machinery operation was soil loosening, while that of medium-sized machinery operation was soil compacting.

  10. [Environmental geochemical baseline of heavy metals in soils of the Ili river basin and pollution evaluation].

    PubMed

    Zhao, Xin-Ru; Nasier, Telajin; Cheng, Yong-Yi; Zhan, Jiang-Yu; Yang, Jian-Hong

    2014-06-01

    Environmental geochemical baseline models of Cu, Zn, Pb, As, Hg were established by standardized method in the ehernozem, chestnut soil, sierozem and saline soil from the Ili river valley region. The theoretical baseline values were calculated. Baseline factor pollution index evaluation method, environmental background value evaluation method and heavy metal cleanliness evaluation method were used to compare soil pollution degrees. The baseline factor pollution index evaluation showed that As pollution was the most prominent among the four typical types of soils within the river basin, with 7.14%, 9.76%, 7.50% of sampling points in chernozem, chestnut soil and sierozem reached the heavy pollution, respectively. 7.32% of sampling points of chestnut soil reached the permitted heavy metal Pb pollution index in the chestnut soil. The variation extent of As and Pb was the largest, indicating large human disturbance. Environmental background value evaluation showed that As was the main pollution element, followed by Cu, Zn and Pb. Heavy metal cleanliness evaluation showed that Cu, Zn and Pb were better than cleanliness level 2 and Hg was the of cleanliness level 1 in all four types of soils. As showed moderate pollution in sierozem, and it was of cleanliness level 2 or better in chernozem, chestnut soil and saline-alkali soil. Comparing the three evaluation systems, the baseline factor pollution index evaluation more comprehensively reflected the geochemical migration characteristics of elements and the soil formation processes, and the pollution assessment could be specific to the sampling points. The environmental background value evaluation neglected the natural migration of heavy metals and the deposition process in the soil since it was established on the regional background values. The main purpose of the heavy metal cleanliness evaluation was to evaluate the safety degree of soil environment.

  11. Competitive adsorption of heavy metals in soil underlying an infiltration facility installed in an urban area.

    PubMed

    Hossain, M A; Furumai, H; Nakajima, F

    2009-01-01

    Accumulation of heavy metals at elevated concentration and potential of considerable amount of the accumulated heavy metals to reach the soil system was observed from earlier studies in soakaways sediments within an infiltration facility in Tokyo, Japan. In order to understand the competitive adsorption behaviour of heavy metals Zn, Ni and Cu in soil, competitive batch adsorption experiments were carried out using single metal and binary metal combinations on soil samples representative of underlying soil and surface soil at the site. Speciation analysis of the adsorbed metals was carried out through BCR sequential extraction method. Among the metals, Cu was not affected by competition while Zn and Ni were affected by competition of coexisting metals. The parameters of fitted 'Freundlich' and 'Langmuir' isotherms indicated more intense competition in underlying soil compared to surface soil for adsorption of Zn and Ni. The speciation of adsorbed metals revealed less selectivity of Zn and Ni to soil organic matter, while dominance of organic bound fraction was observed for Cu, especially in organic rich surface soil. Compared to underlying soil, the surface soil is expected to provide greater adsorption to heavy metals as well as provide greater stability to adsorbed metals, especially for Cu.

  12. Heavy meals in urban roadside soils, part 1: effect of particle size fractions on heavy metals partitioning

    NASA Astrophysics Data System (ADS)

    Wang, Xue-Song; Qin, Yong; Chen, Yong-Kang

    2006-08-01

    Urban roadside soils are important environmental media for assessing heavy metal concentrations in urban environment. However, among other things, heavy metal concentrations are controlled by soil particle grain size fractions. In this study, two roadside sites were chosen within the city of Xuzhou (China) to reflect differences in land use. Bulk soil samples were collected and then divided by particle diameter into five physical size fractions, 500-250, 250-125, 125-74, 74-45, < 45 μm. Concentrations of metals (Ti, Cr, Al, Ga, Pb, Ba, Cd, Co, Cu, Mn, Ni, V, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) were determined for each individual fraction. These metals could be roughly classified into two groups: anthropogenic element (Pb, Ba, Cd, Cu, Zn, Mo, As, Sb, Se, Hg, Bi, Ag) and lithophile element (Ti, Cr, Al, Ga, Co, Mn, Ni, V) in terms of values of enrichment factor. As expected, higher concentrations of anthropogenic heavy metals (Cu, Zn, Mo, As, Hg, Bi, Ag) are observed in the finest particle grain size fraction (i.e. < 45 μm). However, heavy metals Se, Sb and Ba behave independently of selected grain size fractions. From the viewpoint of mass loading, more than 30% of the concentrations for all anthropogenic heavy metals are contributed by the particle grain size fractions of 45-74 μm at site 1 and more than 70% of the concentrations for all heavy metals are contributed by the particle grain size fractions of 45-74 and 74-125 μm at site 2. These results are important for transport of soil-bound heavy metals and pollution control by various remedial options.

  13. Antibiotic resistance of bacteria isolated from heavy metal-polluted soils with different land uses.

    PubMed

    Safari Sinegani, Ali Akbar; Younessi, Nayereh

    2017-09-01

    The main objective of this study was to determine the relationship between the antibiotic and heavy metal tolerance of culturable bacteria isolated from mining waste, pasture, and agricultural soils containing different levels of heavy metals. The populations of total culturable bacteria, and heavy metal- and antibiotic-tolerant bacteria in the soils were enumerated on nutrient agar, nutrient agar amended with metals, and Mueller-Hinton agar amended with antibiotics, respectively. The multiple antibiotic resistance index, and patterns of antibiotic resistance and heavy metal-antibiotic co-resistance were determined for 237 isolates. Among all the samples, those of the tailings of mines with higher levels of heavy metals had the lowest number of bacteria, but a relatively higher abundance of heavy metal- and antibiotic-resistant bacteria. A high degree of resistance was observed for ampicillin and amoxicillin in the isolates from all soils. The agricultural soil isolates had a high prevalence of resistance towards vancomycin, tetracycline, and streptomycin. Among all the tested antibiotics, gentamicin was the most potent. The most frequent pattern of multiple antibiotic resistance in the isolates from agricultural soils was amoxicillin, ampicillin, streptomycin, vancomycin, tetracycline, and doxycycline. The percentage of isolates with multiple antibiotic resistance was considerably higher in the agricultural soils than in the mining waste soils. A high rate of co-resistance towards Hg and antibiotics was observed among the gram-negative isolates, and towards Zn, Ni, Hg, and the beta-lactam antibiotics among the gram-positive isolates. The higher percentage of isolates with multiple antibiotic resistance in the agricultural soils that in the mining waste soils may be related to (1) the level of soil heavy metals, (2) the population and diversity of soil bacteria, (3) the application of manures, and (4) other factors affecting gene transfer between bacteria

  14. Heavy metal accumulation and source analysis in greenhouse soils of Wuwei District, Gansu Province, China.

    PubMed

    Bai, L Y; Zeng, X B; Su, S M; Duan, R; Wang, Y N; Gao, X

    2015-04-01

    Greenhouse soils and arable (wheat field) soil samples were collected to identify the effects of greenhouse cultivation on the accumulation of six heavy metals (Cd, Cu, Zn, Pb, Cr, and Ni) and to evaluate the likely sources responsible for heavy metal accumulation in the irrigated desert soils of Wuwei District, China. The results indicated that the mean concentrations of Cd, Cu, Zn, Pb, Cr, and Ni were 0.421, 33.85, 85.31, 20.76, 53.12, and 28.59 mg kg(-1), respectively. The concentrations of Cd, Cu, and Zn in greenhouse soils were 60, 23, and 14% higher than those in arable soils and 263, 40, and 25% higher than background concentrations of natural soils in the study area, respectively. These results indicated that Cd, Cu, and Zn accumulation occurred in the greenhouse soils, and Cd was the most problematically accumulated heavy metal, followed by Cu and Zn. There was a significant positive correlation between the concentrations of Cd, Cu, and Zn in greenhouse soils and the number of years under cultivation (P < 0.05). Greenhouse cultivation had little impact on the accumulation of Cr, Ni, or Pb. Correlation analysis and principal component analysis suggested that the accumulation of Cd, Cu, and Zn in greenhouse soils resulted mainly from fertilizer applications. Our results indicated that the excessive and long-term use of fertilizers and livestock manures with high heavy metal levels leads to the accumulation of heavy metals in soils. Therefore, rational fertilization programs and reductions in the concentrations of heavy metals in both fertilizers and manure must be recommended to maintain a safe concentration of heavy metals in greenhouse soils.

  15. Heavy metal contents, distribution, and prediction in a regional soil-wheat system.

    PubMed

    Ran, Jing; Wang, Dejian; Wang, Can; Zhang, Gang; Zhang, Hailin

    2016-02-15

    The entry of heavy metals into the food chain is of concern for potential health risks. To investigate the spatial relationships of heavy metals in a regional soil-wheat system, 99 pairs of surface soil (0-15 cm) and wheat grain samples were collected from Changshu, China, a typical county in the Yangtze Delta region. Both soil and wheat grain samples were analyzed for total Cd, Cu, Ni, Pb, and Zn. DTPA-extractable metals and major physico-chemical properties were also determined for soil samples. Moderate accumulation of heavy metals was found in soils and wheat grains, especially Cd. However, the levels were within the target hazard quotients (THQ) safe values with respect to non-carcinogenic risks, but more attention should be paid to Cd. Spatially, Cd, Cu, Ni, and Zn in wheat grains and soils had similar geographical patterns, whereas Pb showed opposite trends. Cross-correlograms further quantitatively confirmed the spatial relationships of heavy metals in wheat grains and soils. In addition, heavy metals in wheat grains were significantly spatially correlated with most soil physio-chemical properties. Particularly, a set of regression models for Cd in wheat grains were established with a maximum predictive success of 65%. These models can be used to predict Cd in wheat grains, and thus allows farmers to decrease the threat by certain framing practices such as ameliorating soil pH or growing a less metal-accumulating cultivar. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Distribution of Heavy Metal Pollution in Surface Soil Samples in China: A Graphical Review.

    PubMed

    Duan, Qiannan; Lee, Jianchao; Liu, Yansong; Chen, Han; Hu, Huanyu

    2016-09-01

    Soil pollution in China is one of most wide and severe in the world. Although environmental researchers are well aware of the acuteness of soil pollution in China, a precise and comprehensive mapping system of soil pollution has never been released. By compiling, integrating and processing nearly a decade of soil pollution data, we have created cornerstone maps that illustrate the distribution and concentration of cadmium, lead, zinc, arsenic, copper and chromium in surficial soil across the nation. These summarized maps and the integrated data provide precise geographic coordinates and heavy metal concentrations; they are also the first ones to provide such thorough and comprehensive details about heavy metal soil pollution in China. In this study, we focus on some of the most polluted areas to illustrate the severity of this pressing environmental problem and demonstrate that most developed and populous areas have been subjected to heavy metal pollution.

  17. Influence of municipal solid waste compost application on heavy metal content in soil.

    PubMed

    Yuksel, Orhan

    2015-06-01

    Municipal solid waste composts (MSWC) are widely used over agricultural lands as organic soil amendment and fertilizer. However, MSWC use may result in various adverse impacts over agricultural lands. Especially, heavy metal contents of MSWC should always be taken into consideration while using in agricultural practices. The present study was conducted to find out heavy metal contents of municipal solid waste compost (MSWC) and to investigate their effects on soils. Experiments were carried out in three replications as field experiments for 2 years. Dry-based MSWC was applied to each plot at the ratios of 0, 40, 80, 120, 160, 200 t ha(-1). Results revealed that heavy metal content of MSWC was within the allowable legal limits. Compost treatments significantly increased Cu, Zn, Ni, Cr, Cd, and Pb content of soils (p < 0.01). Increasing soil heavy metal contents were observed with increasing applied compost doses. Although compost treatments significantly increased soil heavy metal contents, the final contents were still within the allowable legal limits. Results showed that MSWC doses over 10 t ha(-1) may create a heavy metal risk in long term for soils with pH ≥ 7. Therefore, in MSWC use over agricultural lands, heavy metal contents should always be taken into consideration and excessive uses should be avoided.

  18. The use of dialdehyde starch derivatives in the phytoremediation of soils contaminated with heavy metals.

    PubMed

    Antonkiewicz, Jacek; Para, Andrzej

    2016-01-01

    Products of the reaction between dialdehyde starch and Y-NH2 compounds (e.g. semicarbazide or hydrazine) are effective ligands for metal ions. The usefulness of these derivatives was tested in the experiment, both in terms of the immobilization of heavy metal ions in soil and the potential application in phytoextraction processes. The experimental model comprised maize and the ions of such metals as: Zn(II), Pb(II), Cu(II), Cd(II), and Ni(II). The amount of maize yield, as well as heavy metal content and uptake by the aboveground parts and roots of maize, were studied during a three-year pot experiment. The results of the study indicate the significant impact of heavy metals on reduced yield and increased heavy metal content in maize. Soil-applied dialdehyde starch derivatives resulted in lower yields, particularly disemicarbazone (DASS), but in heavy metal-contaminated soils they largely limited the negative impact of these metals both on yielding and heavy metal content in plants, particularly dihydrazone (DASH). It was demonstrated that the application of dihydrazone (DASH) to a soil polluted with heavy metals boosted the uptake of Zn, Pb, Cu, and Cd from the soil, hence there is a possibility to use this compound in the phytoextraction of these metals from the soil. Decreased Ni uptake was also determined, hence the possibility of using this compound in the immobilization of this metal. The study showed that dialdehyde starch disemicarbazone was ineffective in the discussed processes.

  19. Heavy metal concentrations in soils and vegetation in urban areas of Quezon City, Philippines.

    PubMed

    Navarrete, Ian A; Gabiana, Christella C; Dumo, Joan Ruby E; Salmo, Severino G; Guzman, Maria Aileen Leah G; Valera, Nestor S; Espiritu, Emilyn Q

    2017-04-01

    Limited data have been published on the chemistry of urban soils and vegetation in the Philippines. The aim of this study is to quantify the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in soils and vegetation in the urban landscape of Quezon City, Philippines, and to elucidate the relationships between soil properties and the concentration of heavy metals pertaining to different land uses [i.e., protected forest (LM), park and wildlife area (PA), landfill (PL), urban poor residential and industrial areas (RA), and commercial areas (CA)]. Soil (0-15 cm) and senescent plant leaves were collected and were analyzed for soil properties and heavy metal concentrations. Results revealed that the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in urban soils were higher in areas where anthropogenic activities or disturbance (PL, RA, and CA) were dominant as compared to the less disturbed areas (LM and PA). Organic matter and available phosphorous were strongly correlated with heavy metal concentrations, suggesting that heavy metal concentrations were primarily controlled by these soil properties. The average foliar heavy metal concentrations varied, ranging from 0 to 0.4 mg/kg for Cd, 0-10 mg/kg for Cr, 2-22 mg/kg for Cu, 0-5 mg/kg for Pb, and 11-250 mg/kg for Zn. The concentrations of Cd and Cr exceeded the critical threshold concentrations in some plants. Leaves of plants growing in PL (i.e., landfill) showed the highest levels of heavy metal contamination. Our results revealed that anthropogenic activities and disturbance caused by the rapid urbanization of the city are major contributors to the heavy metal accumulation and persistence in the soils in these areas.

  20. Distribution and source analysis of heavy metals in soils and sediments of Yueqing Bay basin, East China Sea.

    PubMed

    Yang, Xiaohui; Wu, Pengbao; Yin, Aijing; Zhang, Huan; Zhang, Ming; Gao, Chao

    2017-02-15

    Concentrations of heavy metals in coastal soils, stream sediments and intertidal sediments of Yueqing Bay basin were analyzed to study their distribution and trace the possible sources. According to various single- and multi-index methods, heavy metal enrichment, especially for Cu, Zn, Cr and Ni in stream sediments, should draw environmental concern. Controlling factors such as inorganic scavengers, organic matter, sample grain size and hydrodynamic conditions were identified to influence the transportation and distribution of metals within coastal soils and sediments. Principal component analysis indicated that most metals in soils and stream sediments originate primarily from natural and anthropogenic sources, respectively. Most metals in intertidal sediments, originating both from natural processes and human activities, tend to be concentrated in fine particles. The exchange of water and sediment between the bay and open waters is strong enough to keep the metals in the tidal flats from rising to very high levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Heavy metal displacement in EDTA-assisted phytoremediation of biosolids soil.

    PubMed

    Liphadzi, S; Kirkham, M B

    2006-01-01

    Chelating agents are added to soil to solubilise the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with biosolids following solubilisation with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids in a soil from a sludge farm that had received biosolids for 25 years. The soil was placed in columns in a greenhouse. Columns either had a plant (poplar) or no plant. After the poplar seedlings had grown for 144 d, the tetrasodium salt of the chelating agent EDTA was irrigated onto the surface of the soil at a rate of 1 g per kg of soil. Drainage water was analysed for three toxic heavy metals and four essential heavy metals. Without EDTA, concentrations of the seven heavy metals in the leachate from columns with or without plants were low or below detection limits. With or without plants, the EDTA mobilised all heavy metals and increased their concentration in drainage water. Without plants, the concentrations of Cd, Cu, Fe, and Zn in the leachate from columns with EDTA were above drinking-water standards. The presence of poplar plants in the soil reduced the concentrations of Cu, Fe, and Zn in the leachate so it fell within drinking-water standards. Concentrations of Cd and Pb in the leachate remained above drinking-water standards with or without plants.

  2. Contamination of soils with heavy metals and metalloids and its ecological hazard (analytic review)

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.

    2013-07-01

    According to the present-day ecotoxicologic data, hazardous heavy metals/metalloids form the following sequence in the soil: Se > Tl > Sb > Cd > V > Hg > Ni > Cu > Cr > As > Ba. This sequence differs from the well-known series of the hazardous heavy elements, in which the danger of Pb and Zn is exaggerated, whereas that of V, Sb, and Ba, is underestimated. Tl also should be included in the list of hazardous elements in the soil. At present, the stress is made on the investigation of heavy metals/metalloids in agricultural soils rather than in urban soils, as the former produce contaminated products poisoning both animals and humans. The main sources of soil contamination with heavy metals are the following: aerial deposition from stationary and moving sources; hydrogenic contamination from the industrial sewage discharging into water bodies; sewage sediments; organic and mineral fertilizers and chemicals for plant protection, tailing dumps of ash, slag, ores, and sludge. In addition to the impact on plants and groundwater, heavy metals/metalloids exert a negative effect on the soil proper. Soil microorganisms appear to be very sensitive to the influence of heavy elements.

  3. Role of reducing agent in extraction of arsenic and heavy metals from soils by use of EDTA.

    PubMed

    Kim, Eun Jung; Jeon, Eun-Ki; Baek, Kitae

    2016-06-01

    Although many metal-contaminated sites contain both anionic arsenic and cationic heavy metals, the current remediation technologies are not effective for the simultaneous removal of both anionic and cationic elements from the contaminated sites due to their different characteristics. In this study, the role of reducing agent in simultaneous extraction of As, Cu, Pb, and Zn from contaminated soils was investigated using EDTA. The addition of reducing agents, which includes sodium oxalate (Na2C2O4), ascorbic acid (C6H8O6) and sodium dithionite (Na2S2O4), greatly enhanced the EDTA extraction of both As and heavy metals from the contaminated soils due to the increased mobility of the metals under the reduced conditions. The extent of the enhancement of the EDTA extraction was greatly affected by the reducing conditions. Strong reducing conditions (0.1 M of dithionite) were required for the extraction of metals strongly bound to the soil, while weak reducing conditions (0.01 M of dithionite or 0.1 M of oxalate/ascorbic acid) were sufficient for extraction of metals that were relatively weakly bound to the soil. An almost 90% extraction efficiency of total metals (As, Cu, Zn, and Pb) was obtained from the contaminated soils using the combination of dithionite and EDTA. Our results clearly showed that the combination of dithionite and EDTA can effectively extract As and heavy metals simultaneously from soils under a wide range of pH conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. NASA SMAP Images Show Texas Soil Moisture Conditions Before/After Hurricane Harvey's Landfall

    NASA Image and Video Library

    2017-08-29

    Images of soil moisture conditions in Texas near Houston, generated by NASA's Soil Moisture Active Passive (SMAP) satellite before and after the landfall of Hurricane Harvey can be used to monitor changing ground conditions due to Harvey's rainfall. As seen in the left panel, SMAP observations show that soil surface conditions were already very wet a few days before the hurricane made landfall (August 21/22), with moisture levels in the 20 to 40 percent range. Such saturated soil surfaces contributed to the inability of water to infiltrate more deeply into soils, thereby increasing the likelihood of flooding. After Harvey made landfall, the southwest portion of Houston became exceptionally wet, as seen in the right panel image from August 25/26, signaling the arrival of heavy rains and widespread flooding. https://photojournal.jpl.nasa.gov/catalog/PIA21926

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

    PubMed Central

    Arshad, Jahanzaib; Iqbal, Farhat; Sajjad, Ashif; Mehmood, Zahid

    2014-01-01

    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. PMID:25276818

  6. Pollution status of Pakistan: a retrospective review on heavy metal contamination of water, soil, and vegetables.

    PubMed

    Waseem, Amir; Arshad, Jahanzaib; Iqbal, Farhat; Sajjad, Ashif; Mehmood, Zahid; Murtaza, Ghulam

    2014-01-01

    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.

  7. Estimation of heavy metal-contaminated soils' mechanical characteristics using electrical resistivity.

    PubMed

    Chu, Ya; Liu, Songyu; Wang, Fei; Cai, Guojun; Bian, Hanliang

    2017-05-01

    Under the process of urbanization in China, more and more attention has been paid to the reuse of heavy metal-contaminated sites. The shear characteristics of heavy metal-contaminated soils are investigated by electrical detection in this paper. Three metal ions (Zn(2+), Cd(2+), and Pb(2+)) were used, the metal concentrations of which are 50, 166.67, 500, 1666.67, and 5000 mg/kg, respectively. Direct shear tests were used to investigate the influence of heavy metal ions on the shear characters of soil samples. It is found that with the addition of heavy metal ions, the shear strength, cohesion, and friction angle of contaminated soils are higher than the control samples. The higher concentration of heavy metal ions penetrated in soils, the higher these engineering characteristics of contaminated soils observed. In addition, an electrical resistivity detection machine is used to evaluate the shear characteristics of contaminated soils. The electrical resistivity test results show that there is a decreasing tendency of resistivity with the increase of heavy metal ion concentrations in soils. Compared with the electrical resistivity and the shear characteristics of metal-contaminated soils, it is found that, under fixed compactness and saturation, shear strength of metal-contaminated soils decreased with the increase of resistivity. A basic linear relationship between C/log(N + 10) and resistivity can be observed, and there is a basic linear relationship between φ/log(N + 10) and resistivity. Besides, a comparison of the measured and predicted shear characteristics shows a high accuracy, indicating that the resistivity can be used to evaluate the shear characteristics of heavy metal contaminated soils.

  8. Heavy metals concentration and availability of different soils in Sabzevar area, NE of Iran

    NASA Astrophysics Data System (ADS)

    Mazhari, Seyed Ali; Sharifiyan Attar, Reza; Haghighi, Faezeh

    2017-10-01

    Soils developed in the Sabzevar ophiolitic area originate from different bedrocks. All samples display similar physico-chemical properties, but heavy metal concentrations vary extremely in different soil samples. Serpentine soils have the highest total concentration of Cr, Ni and Co; while soils derived from mafic rocks (olivine basalts and hornblende gabbros) show the highest Cu (85.29-109.11 ppm) and Zn (46.88-86.60 ppm). The DTPA-extraction of soil samples indicates that the order of metal bioavailability was Crheavy metal availabilities of studied soils are not quite similar to total concentrations. The bedrock properties and minerals involved during soil formations have a significant effect on the metals availability. The soils derived from volcanic rocks have, in general, higher metal bioavailability than those derived from plutonic rocks. Serpentine soils with high concentration of Co and Cr, exhibit low availability of these elements (<1% of total Cr and <10% of total Co), whereas olivine basalt samples release high values (>3% of total Cr; >12% of total Co and >17% of total Zn). Oxide minerals (such as chromite and magnetite) in Sabzevar soils play as resistant minerals and impede the heavy metal availability; while forsterite, pyroxene, serpentine and talc are more labile and show higher DTPA-extractable of heavy metals.

  9. Influence of the soil sealing on the geoaccumulation index of heavy metals and various pollution factors.

    PubMed

    Charzyński, Przemysław; Plak, Andrzej; Hanaka, Agnieszka

    2017-02-01

    Soil sealing belongs to the most destructive and damaging processes to the soil environment. Soil sealing interrupts or greatly restricts the exchange of matter and energy between the biosphere, hydrosphere, and atmosphere and the soil environment. The aim of this study was to compare the content of heavy metals (Cd, Cr, Cu, Hg, Fe, Ni, Pb, Zn) of Ekranic Technosols by applying indicators such as geoaccumulation index (I geo), enrichment factor (EF), and pollution load index (PLI), which allowed to determine quantitatively the impact of the soil sealing degree on the content of heavy metals and to distinguish natural from anthropogenic sources of origin of heavy metals. In general, 42 soils from different parts of the city of Toruń (NW Poland) were sampled and divided into three groups according to the degree of soil sealing: completely sealed with asphalt or concrete (A), semi-permeable (partially sealed with cobblestones and concrete paving slabs (B)), and reference (non-sealed) (C). The results indicate that the artificial sealing in urban areas slightly affects the content of heavy metals in soils. However, based on PLI, I geo, and EF, it was found that the sealing has influence on soil properties and unsealed soil is the most exposed to the accumulation of pollutants.

  10. Heavy metal pollution of soils affected by the Guadiamar toxic flood.

    PubMed

    Cabrera, F; Clemente, L; Díaz Barrientos, E; López, R; Murillo, J M

    1999-12-06

    Total heavy metal concentrations were determined in soil samples of seven selected areas along the Guadiamar river valley affected by the toxic flood, after removal of the deposited sludge. Mean total concentrations of nine elements (As, Au, Bi, Cd, Cu, Pb, Sb, Tl and Zn) out of the 23 (As, Au, Ba, Be, Bi, Cd, Co, Cr, Cu, In, Mn, Mo, Ni, Pb, Sb, Sc, Sn, Th, Tl, U, V, Y and Zn) analysed were higher in sludge-covered soils than in unaffected soils. Mean values of total As, Au, Pb, Sb, Tl and Zn in sludge-affected soils were higher than the upper limits for normal soils world-wide. Mean concentrations of Bi, Cd and Cu were within these ranges, although some individual values exceeded the upper limits. In all sampling areas, severe heavy metal pollution was observed in the superficial layers (0-20 cm) of most of the affected soils, which decreased downward in the soil profile. Generally, in soils with more than 25% of clay, concentration of heavy metals below the 20-cm depth decreased to values close to those of the background level of the Guadiamar valley soils, while in coarser soils, heavy metal pollution penetrated below this depth, being noticeable down to a depth of at least 50-80 cm.

  11. Phytoextraction of heavy metals by canola (Brassica napus) and radish (Raphanus sativus) grown on multicontaminated soil.

    PubMed

    Marchiol, L; Assolari, S; Sacco, P; Zerbi, G

    2004-11-01

    Phytoextraction can provide an effective in situ technique for removing heavy metals from polluted soils. The experiment reported in this paper was undertaken to study the basic potential of phytoextraction of Brassica napus (canola) and Raphanus sativus (radish) grown on a multi-metal contaminated soil in the framework of a pot-experiment. Chlorophyll contents and gas exchanges were measured during the experiment; the heavy metal phytoextraction efficiency of canola and radish were also determined and the phytoextraction coefficient for each metal calculated. Data indicated that both species are moderately tolerant to heavy metals and that radish is more so than canola. These species showed relatively low phytoremediation potential of multicontaminated soils. They could possibly be used with success in marginally polluted soils where their growth would not be impaired and the extraction of heavy metals could be maintained at satisfying levels.

  12. Ionomics: Genes and QTLs controlling heavy metal uptake in perennial grasses grown on phytoxic soil

    USDA-ARS?s Scientific Manuscript database

    Perennial grasses occupy diverse soils throughout the world, including many sites contaminated with heavy metals. Uncovering the genetic architecture of QTLs controlling mineral homoeostasis is critical for understanding the biochemical pathways that determine the elemental profiles of perennial pl...

  13. Fluctuating glasma initial conditions and flow in heavy ion collisions.

    PubMed

    Schenke, Björn; Tribedy, Prithwish; Venugopalan, Raju

    2012-06-22

    We compute initial conditions in heavy ion collisions within the color glass condensate framework by combining the impact parameter dependent saturation model with the classical Yang-Mills description of initial Glasma fields. In addition to fluctuations of nucleon positions, this impact parameter dependent Glasma description includes quantum fluctuations of color charges on the length scale determined by the inverse nuclear saturation scale Q(s). The model naturally produces initial energy fluctuations that are described by a negative binomial distribution. The ratio of triangularity to eccentricity ε(3)/ε(2) is close to that in a model tuned to reproduce experimental flow data. We compare transverse momentum spectra and v(2,3,4)(p(T)) of pions from different models of initial conditions using relativistic viscous hydrodynamic evolution.

  14. Heavy Metal Displacement in Chelate-Assisted Phytoremediation of Biosolids Soil

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

    Heavy metals in biosolids (sewage sludge) applied to land contaminate the soil. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with biosolids following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals, as affected by a chelate, in soil (Haynie very fine sandy loam) from a 25-year old sludge farm. Soil columns (105 cm long; 39 cm in diameter) either had a plant (hybrid poplar; Populus deltoides Marsh. x P. nigra L.) or no plant. When the poplars were 144 days old, the tetrasodium salt of the chelating agent EDTA (ethylenediamine-tetraacetic acid) was irrigated onto the soil at a rate of 1 g per kg of soil. Drainage water, soil, and plants were analyzed for three toxic heavy metals (Cd, Ni, Pb) and four essential heavy metals (Cu, Fe, Mn, Zn). Without EDTA, concentrations of the seven heavy metals in the leachate from columns with or without plants were low or below detection limits. With or without plants, the EDTA mobilized all heavy metals and increased their concentration in drainage water. Without plants, the concentrations of Cd, Cu, Fe, Pb, and Zn in the leachate from columns with EDTA were above drinking-water standards. (There is no drinking-water standard for Ni.) The presence of poplar plants in the soil reduced the concentrations of Cu, Fe, and Zn in the leachate so it fell within drinking-water standards. Concentrations of Cd and Pb in the leachate remained above drinking-water standards with or without plants. At harvest (124 days after the EDTA application), total concentration of each heavy metal in the soil at different depths in the columns with EDTA was similar to that in the columns without EDTA. The chelate did not affect the concentration of heavy metals in the roots, stems, or leaves

  15. Stability and heavy metal distribution of soil aggregates affected by application of apatite, lime, and charcoal.

    PubMed

    Cui, Hongbiao; Ma, Kaiqiang; Fan, Yuchao; Peng, Xinhua; Mao, Jingdong; Zhou, Dongmei; Zhang, Zhongbin; Zhou, Jing

    2016-06-01

    Only a few studies have been reported on the stability and heavy metal distribution of soil aggregates after soil treatments to reduce the availability of heavy metals. In this study, apatite (22.3 t ha(-1)), lime (4.45 t ha(-1)), and charcoal (66.8 t ha(-1)) were applied to a heavy metal-contaminated soil for 4 years. The stability and heavy metal distribution of soil aggregates were investigated by dry and wet sieving. No significant change in the dry mean weight diameter was observed in any treatments. Compared with the control, three-amendment treatments significantly increased the wet mean weight diameter, but only charcoal treatment significantly increased the wet aggregate stability. The soil treatments increased the content of soil organic carbon, and the fraction 0.25-2 mm contained the highest content of soil organic carbon. Amendments' application slightly increased soil total Cu and Cd, but decreased the concentrations of CaCl2 -extractable Cu and Cd except for the fraction <0.053 mm. The fractions >2 and 0.25-2 mm contained the highest concentrations of CaCl2-extractable Cu and Cd, accounted for about 74.5-86.8 % of CaCl2-extractable Cu and Cd in soil. The results indicated that amendments' application increased the wet soil aggregate stability and decreased the available Cu and Cd. The distribution of available heavy metals in wet soil aggregates was not controlled by soil aggregate stability, but possibly by soil organic carbon.

  16. Bioavailability of heavy metals in strongly acidic soils treated with exceptional quality biosolids

    SciTech Connect

    Basta, N.T.; Sloan, J.J.

    1999-03-01

    New federal regulations may increase application of exceptional quality (EQ) biosolids to acidic soils, and information on the effect of this practice on bioavailability of heavy metal is limited. The objective of this study was to compare bioavailability of heavy metal in soil treated with nonalkaline or alkaline EQ biosolids with limestone-treated soils. Three acidic soils (pH 3.7--4.3) were treated with three amounts of lime-stabilized biosolids (LS), anaerobic-digested biosolids (AN), or agricultural limestone (L), and incubated at 25 C. Soil solution Cd, Zn, and other chemical constituents were measured at 1, 30, 90, and 180 d incubation. Soil solution Cd and Zn were AN > LS {ge} L, C. Soil solution Cd and Zn increased with AN applied but decreased wit h LS applied. The high application of LS had soil solution Zn dramatically decreased at soil pH > 5.5 and >5.1, respectively. Soil solution Cd and Zn increases were AN > LS with incubation time. Biosolids treatments increased heavy metal in Ca(NO{sub 3}){sub 2} and NaOAc fractions. Except for Cd, most metal from biosolids were in EDTA and HNO{sub 3} fractions. Heavy metal bioavailability, measured using lettuce (Latuca sativa L.), was AN > LS {ge} L, C. Although state regulations prohibiting application of nonalkaline EQ biosolids to acidic soil is a prudent practice, application of EQ alkaline biosolids that achieves soil pH > 5 minimizes risk from soil solution Cd and Zn and plant uptake of heavy metal.

  17. Soil characteristics and heavy metal accumulation by native plants in a Mn mining area of Guangxi, South China.

    PubMed

    Liu, Jie; Zhang, Xue-hong; Li, Tian-yu; Wu, Qing-xin; Jin, Zhen-jiang

    2014-04-01

    Revegetation and ecological restoration of a Mn mineland are important concerns in southern China. To determine the major constraints for revegetation and select suitable plants for phytorestoration, pedological and botanical characteristics of a Mn mine in Guangxi, southern China were investigated. All the soils were characterized by low pH and low nitrogen and phosphorus levels except for the control soil, suggesting that soil acidity and poor nutrition were disadvantageous to plant growth. In general, the studied mine soils had normal organic matter (OM) and cation exchange capacity (CEC). However, OM (8.9 g/kg) and CEC (7.15 cmol/kg) were very low in the soils from tailing dumps. The sandy texture and nutrient deficiency made it difficult to establish vegetation on tailing dumps. Mn and Cd concentrations in all soils and Cr and Zn concentrations in three soils exceeded the pollution threshold. Soil Mn and Cd were above phytotoxic levels, indicating that they were considered to be the major constraints for phytorestoration. A botanical survey of the mineland showed that 13 plant species grew on the mineland without obvious toxicity symptoms. High Mn and Cd concentrations have been found in the aerial parts of Polygonum pubescens, Celosia argentea, Camellia oleifera, and Solanum nigrum, which would be interesting for soil phytoremediation. Miscanthus floridulus, Erigeron acer, Eleusina indica, and Kummerowia striata showed high resistance to the heavy metal and harsh condition of the soils. These species could be well suited to restore local degraded land in a phytostabilization strategy.

  18. Uncertainty assessment of heavy metal soil contamination mapping using spatiotemporal sequential indicator simulation with multi-temporal sampling points.

    PubMed

    Yang, Yong; Christakos, George

    2015-09-01

    Mapping the space-time distribution of heavy metals in soils plays a key role in contaminated site classification under conditions of in situ uncertainty, whereas uncertainty assessment is based on the quantification of the specific uncertainties in terms of exceedance probabilities. Geostatistical space-time kriging (STK) is increasingly used to estimate pollutant concentrations in soils. Sequential indicator simulation (SIS) technique is popular in uncertainty assessment of heavy metal contamination of soils. However, these techniques cannot handle multi-temporal data. In this work, spatiotemporal sequential indicator simulation (STSIS) based on an additive space-time semivariogram model (STSIS_A) and on a non-separable space-time semivariogram model (STSIS_NS) was used to assimilate multi-temporal data in the mapping and uncertainty assessment of heavy metal distributions in contaminated soils. Cu concentrations in soils sampled during the period 2010-2014 in the Qingshan district (Wuhan City, Hubei Province, China) were used as the experimental data set. Based on a number of STSIS realizations, we assessed different kinds of mapping uncertainty, including single-location uncertainty during 1 year and during multiple years, multi-location uncertainty during 1 year, and during multiple years. The comparison of the STSIS technique vs. SIS and STK techniques showed that STSIS performs better than both STK and SIS.

  19. Geostatistical conditional simulation for the assessment of contaminated land by abandoned heavy metal mining.

    PubMed

    Ersoy, Adem; Yunsel, Tayfun Yusuf; Atici, Umit

    2008-02-01

    Abandoned mine workings can undoubtedly cause varying degrees of contamination of soil with heavy metals such as lead and zinc has occurred on a global scale. Exposure to these elements may cause to harm human health and environment. In the study, a total of 269 soil samples were collected at 1, 5, and 10 m regular grid intervals of 100 x 100 m area of Carsington Pasture in the UK. Cell declustering technique was applied to the data set due to no statistical representativity. Directional experimental semivariograms of the elements for the transformed data showed that both geometric and zonal anisotropy exists in the data. The most evident spatial dependence structure of the continuity for the directional experimental semivariogram, characterized by spherical and exponential models of Pb and Zn were obtained. This study reports the spatial distribution and uncertainty of Pb and Zn concentrations in soil at the study site using a probabilistic approach. The approach was based on geostatistical sequential Gaussian simulation (SGS), which is used to yield a series of conditional images characterized by equally probable spatial distributions of the heavy elements concentrations across the area. Postprocessing of many simulations allowed the mapping of contaminated and uncontaminated areas, and provided a model for the uncertainty in the spatial distribution of element concentrations. Maps of the simulated Pb and Zn concentrations revealed the extent and severity of contamination. SGS was validated by statistics, histogram, variogram reproduction, and simulation errors. The maps of the elements might be used in the remediation studies, help decision-makers and others involved in the abandoned heavy metal mining site in the world.

  20. Spatial distribution of selected heavy metals and soil fertility status in south-eastern Serbia

    NASA Astrophysics Data System (ADS)

    Saljnikov, E.; Mrvic, V.; Cakmak, D.; Nikoloski, M.; Perovic, V.; Kostic, L.; Brebanovic, B.

    2009-04-01

    Environmental pollution by heavy metals is one of the most powerful factors destroying biosphere components that directly affecting agricultural production quality and therefore health of human and animals. Regional soil contamination by heavy metals occurs mainly in industrial areas and in big cities. However, pollutants can be air-and/or water-transferred to big distances and may accumulated far from industrial zone what makes difficult to distinguish original background concentrations of heavy metals in soil. Our study covers south-eastern part of Serbia and is a part of a big project studying soil fertility and heavy metal contamination all around Serbia. Diverse natural characteristics and heterogeneity of soil cover, as well as, human activity greatly influenced soil fertility parameters, while, diverse geological substrate and human activity determined the level of potential geochemical pollution. There are number of industrial factories functioning from the last century on the studied area. Also, close to studied area, there was a mining in the middle of the last century. About 600 soil samples from surface 0-30 cm were investigated for main soil fertility characteristics (pH, humus, available K and P) and concentrations of selected heavy metals (As, Cd, Cr, Ni and Pb). Soils graded as very acidic cover 46% of the area, which are mainly mountains with acidic parent materials. Content of humus in 41% of soil samples were below 3%. The most of the soils (71%) are weakly supplied available phosphorus. While available potassium in more than 70% is presented in the concentrations enough for good soil quality. So, about 75% of studied area is characterized with unfavorable soil fertility properties (extremly low soil pH, very low content of available P, about half of the area maintained low soil humus) that is located under forests, meadows and pastures. Content of heavy metals on studied area in 80% of sampled soils was below maximum allowed concentrations

  1. Removal of heavy metals and arsenic from contaminated soils using bioremediation and chelant extraction techniques.

    PubMed

    Vaxevanidou, Katerina; Papassiopi, Nymphodora; Paspaliaris, Ioannis

    2008-02-01

    A combined chemical and biological treatment scheme was evaluated in this study aiming at obtaining the simultaneous removal of metalloid arsenic and cationic heavy metals from contaminated soils. The treatment involved the use of the iron reducing microorganism Desulfuromonas palmitatis, whose activity was combined with the chelating strength of EDTA. Taking into consideration that soil iron oxides are the main scavengers of As, treatment with iron reducing microorganisms aimed at inducing the reductive dissolution of soil oxides and thus obtaining the release of the retained As. The main objective of using EDTA was the removal of metal contaminants, such as Pb and Zn, through the formation of soluble metal chelates. Experimental results however indicated that EDTA was also indispensable for the biological reduction of Fe(III) oxides. The bacterial activity was found to have a pronounced positive effect on the removal of arsenic, which increased from the value of 35% obtained during the pure chemical treatment up to 90% in the presence of D. palmitatis. In the case of Pb, the major part, i.e. approximately 85%, was removed from soil with purely chemical mechanisms, whereas the biological activity slightly improved the extraction, increasing the final removal up to 90%. Co-treatment had negative effect only for Zn, whose removal was reduced from 80% under abiotic condition to approximately 50% in the presence of bacteria.

  2. Assessment of spatial distribution of soil heavy metals using ANN-GA, MSLR and satellite imagery.

    PubMed

    Naderi, Arman; Delavar, Mohammad Amir; Kaboudin, Babak; Askari, Mohammad Sadegh

    2017-05-01

    This study aims to assess and compare heavy metal distribution models developed using stepwise multiple linear regression (MSLR) and neural network-genetic algorithm model (ANN-GA) based on satellite imagery. The source identification of heavy metals was also explored using local Moran index. Soil samples (n = 300) were collected based on a grid and pH, organic matter, clay, iron oxide contents cadmium (Cd), lead (Pb) and zinc (Zn) concentrations were determined for each sample. Visible/near-infrared reflectance (VNIR) within the electromagnetic ranges of satellite imagery was applied to estimate heavy metal concentrations in the soil using MSLR and ANN-GA models. The models were evaluated and ANN-GA model demonstrated higher accuracy, and the autocorrelation results showed higher significant clusters of heavy metals around the industrial zone. The higher concentration of Cd, Pb and Zn was noted under industrial lands and irrigation farming in comparison to barren and dryland farming. Accumulation of industrial wastes in roads and streams was identified as main sources of pollution, and the concentration of soil heavy metals was reduced by increasing the distance from these sources. In comparison to MLSR, ANN-GA provided a more accurate indirect assessment of heavy metal concentrations in highly polluted soils. The clustering analysis provided reliable information about the spatial distribution of soil heavy metals and their sources.

  3. A feasibility study of perennial/annual plant species to restore soils contaminated with heavy metals

    NASA Astrophysics Data System (ADS)

    Zacarías, Montserrat; Beltrán, Margarita; Gilberto Torres, Luis; González, Abelardo

    A feasibility study was carried out to evaluate the application of perennial/annual plant species in a phytoextraction process of a previously washed industrial urban soil contaminated by nickel, arsenic and cupper. The plant species selected for this study were Ipomea (Ipomea variada); grass (Poa pratensis); grass mixture (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum sp.); Monks Cress (Tropaeolum majus); ficus (Ficus benajamina) and fern (Pteris cretica). Soil was characterized and it presented the following heavy metals concentrations (dry weight): 80 mg of Ni/kg, 456-656 mg of As/kg and 1684-3166 mg of Cu/kg. Germination and survival in contaminated soil tests were conducted, from these, P. pratensis was discarded and the rest of plant species tested were used for the phytoextraction selection test. After 4 months of growth, biomass production was determined, and content of Ni, As and Cu was analyzed in plant’s tissue. Metal biological absorption coefficient (BAC), bio-concentration factor (BCF) and translocation factor (TF), were calculated. Regarding to biomass generation it was observed, in every case, an inhibition of the plant growth compared with blanks sown in a non contaminated soil; inhibition ranged from 22.5% for the Monk cress to 98% for Ipomea. Even though the later presented high BAC, BCF and TF, its growth was severely inhibited, and therefore, due its low biomass generation, it is not recommended for phytoextraction under conditions for this study. Heavy metals concentrations in plant’s tissue (dry weight) were as high as 866 mg Cu/kg and 602 mg As/kg for grass mixture; and 825 mg As/kg was observed for Monks cress. Grass mixture and monks cress had high BAC, BCF and TF, also they had high metal concentrations in its plants tissues and the lowest growth inhibition rates; hence the application in phytoextraction processes of these plants is advisable.

  4. Retention of heavy metals by carboxyl functional groups of biochars in small arms range soil

    USDA-ARS?s Scientific Manuscript database

    Long-term effectiveness of biochar for heavy metal stabilization depends upon biochar’s sorptive property and recalcitrance in soil. To understand the role of carboxyl functional groups on heavy metal stabilization, cottonseed hull biochar and flax shive steam activated biochar having low O/C ratio...

  5. Heavy metals in Iberian soils: Removal by current adsorbents/amendments and prospective for aerogels.

    PubMed

    Vareda, João P; Valente, Artur J M; Durães, Luisa

    2016-11-01

    Heavy metals are dangerous pollutants that in spite of occurring naturally are released in major amounts to the environment due to anthropogenic activities. After being released in the environment, the heavy metals end up in the soils where they accumulate as they do not degrade, adversely affecting the biota. Because of the dynamic equilibria between soil constituents, the heavy metals may be present in different phases such as the solid phase (immobilized contaminants) or dissolved in soil solution. The latter form is the most dangerous because the ions are mobile, can leach and be absorbed by living organisms. Different methods for the decontamination of polluted soils have been proposed and they make use of two different approaches: mobilizing the heavy metals, which allows their removal from soil, or immobilization that maintains the metal concentrations in soils but keeps them in an inert form due to mechanisms like precipitation, complexation or adsorption. Mobilization of the heavy metals is known to cause leaching and increase plant uptake, so this treatment can cause greater problems. Aerogels are incredible nanostructured, lightweight materials with high surface area and tailorable surface chemistry. Their application in environmental cleaning has been increasing in recent years and very promising results have been obtained. The functionalization of the aerogels can give them the ability to interact with heavy metals, retaining the latter via strong adsorptive interactions. Thus, this review surveys the existing literature for remediation of soils using an immobilization approach, i.e. with soil amendments that increase the soil sorption/retention capacity for heavy metals. The considered framework was a set of heavy metals with relevance in polluted Iberian soils, namely Cd, Cr, Cu, Ni, Pb and Zn. Moreover, other adsorbents, especially aerogels, have been used for the removal of these contaminants from aqueous media; because groundwater and soil

  6. [Soil Heavy Metal Spatial Distribution and Source Analysis Around an Aluminum Plant in Baotou].

    PubMed

    Zhang, Lian-ke; Li, Hai-peng; Huang, Xue-min; Li, Yu-mei; Jiao, Kun-ling; Sun, Peng; Wang, Wei-da

    2016-03-15

    The soil with 500 m distance from an aluminum plant in Baotou was studied. A total of 64 soil samples were taken from the 0-5 cm, 5-20 cm, 20-40 cm and 40-60 cm layers, and the contents of Cu, Pb, Zn, Cr, Cd, Ni and Mn were tested, respectively. The correlation analysis and principal component analysis were used to identify the sources of these heavy metals in soils. The results suggested that the contents of Cu, Pb, Zn, Cr, Cd, Ni and Mn in study area were 32.9, 50.35, 69.92, 43.78, 0.54, 554.42 and 36.65 mg · kg⁻¹ respectively. All seven heavy metals tested were overweight compared with the background values of soil in Inner Mongolia. The spatial distribution of heavy metals showed that the horizontal distribution of heavy metals was obviously enriched in the southwest, while in vertical distribution, the heavy metal content (0 to 5 cm) was highest in the surface soil, and the heavy metal content decreased with increasing depth and tended to be stabilized when the depth was over 20 cm. Source analysis showed that the source of Cu, Zn, Cr and Mn might be influenced by the aluminum plant and the surrounding industrial activity. The source of Pb and Cd might be mainly related to road transportation. The source of Ni may be affected by agricultural activities and soil parent material together.

  7. Multivariate statistical analysis of heavy metal concentration in soils of Yelagiri Hills, Tamilnadu, India - Spectroscopical approach

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, A.; Ravisankar, R.; Harikrishnan, N.; Satapathy, K. K.; Prasad, M. V. R.; Kanagasabapathy, K. V.

    2015-02-01

    Anthropogenic activities increase the accumulation of heavy metals in the soil environment. Soil pollution significantly reduces environmental quality and affects the human health. In the present study soil samples were collected at different locations of Yelagiri Hills, Tamilnadu, India for heavy metal analysis. The samples were analyzed for twelve selected heavy metals (Mg, Al, K, Ca, Ti, Fe, V, Cr, Mn, Co, Ni and Zn) using energy dispersive X-ray fluorescence (EDXRF) spectroscopy. Heavy metals concentration in soil were investigated using enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI) to determine metal accumulation, distribution and its pollution status. Heavy metal toxicity risk was assessed using soil quality guidelines (SQGs) given by target and intervention values of Dutch soil standards. The concentration of Ni, Co, Zn, Cr, Mn, Fe, Ti, K, Al, Mg were mainly controlled by natural sources. Multivariate statistical methods such as correlation matrix, principal component analysis and cluster analysis were applied for the identification of heavy metal sources (anthropogenic/natural origin). Geo-statistical methods such as kirging identified hot spots of metal contamination in road areas influenced mainly by presence of natural rocks.

  8. Potential of siderophore production by bacteria isolated from heavy metal: polluted and rhizosphere soils.

    PubMed

    Hussein, Khalid A; Joo, Jin Ho

    2014-06-01

    Recently, heavy metals have been shown to have a stimulating effect on siderophore biosynthesis in various bacteria. In addition, several studies have found that siderophore production is greater in bacteria isolated from soil near plant roots. The aim of this study was to compare the production of siderophores by bacterial strains isolated from heavy metal-contaminated and uncontaminated soils. Chrome azurol sulphonate was used to detect siderophore secretion by several bacterial strains isolated from heavy metal-contaminated and rhizosphere-uncontaminated soils with both a qualitative disc diffusion method and a quantitative ultraviolet spectrophotometric method. Siderophore production by rhizosphere bacteria was significantly greater than by bacteria isolated from contaminated soil. The Pearson's correlation test indicated a positive correlation between the amount of siderophore produced by bacteria isolated from the rhizosphere using the quantitative and qualitative detection methods and the amount of heavy metal in the soil. However, a significant negative correlation was observed between the amount of siderophore produced by bacteria isolated from heavy metal-contaminated soil and the amount of heavy metal (r value of -0.775, P < 0.001).

  9. Heavy metal stabilization in contaminated soil by treatment with calcined cockle shell.

    PubMed

    Islam, Mohammad Nazrul; Taki, Golam; Nguyen, Xuan Phuc; Jo, Young-Tae; Kim, Jun; Park, Jeong-Hun

    2017-01-17

    In several previous studies, the efficacy of various liming waste materials on the immobilization of heavy metals has been tested and it was found that soils contaminated with heavy metals can be stabilized using this technique. Since lime (CaO) has been identified as the main phase of calcined cockle shell (CCS), it was hypothesized that CCS could be used as a soil amendment to immobilize heavy metals in soil. However, to date, no studies have been conducted using CCS. In this study, the effectiveness of CCS powder on the immobilization of Cd, Pb, and Zn in mine tailing soil was evaluated. After 28 days of incubation, the treated soil samples were exposed to weathering (four cycles of freezing-thawing and four cycles of wetting-drying) for 8 days before being subjected to a leaching test. The results of this study revealed that the soil pH increased from 7.5 to 12.2 with the addition of 5% CCS. A similar soil pH was obtained when the soil was amended with 5% pure CaO. By leaching with 0.1 M HCl, extracted Cd, Pb, and Zn were reduced by up to 85, 85, and 91%, respectively. Therefore, CCS is suggested as a low-cost lime-based soil amendment for stabilizing heavy metals in abandoned mining sites.

  10. Microbial indicators of heavy metal contamination in urban and rural soils.

    PubMed

    Yang, Yuangen; Campbell, C D; Clark, L; Cameron, C M; Paterson, E

    2006-06-01

    Urban soils and especially their microbiology have been a neglected area of study. In this paper, we report on microbial properties of urban soils compared to rural soils of similar lithogenic origin in the vicinity of Aberdeen city. Significant differences in basal respiration rates, microbial biomass and ecophysiological parameters were found in urban soils compared to rural soils. Analysis of community level physiological profiles (CLPP) of micro-organisms showed they consumed C sources faster in urban soils to maintain the same level activity as those in rural soils. Cu, Pb, Zn and Ni were the principal elements that had accumulated in urban soils compared with their rural counterparts with Pb being the most significant metal to distinguish urban soils from rural soils. Sequential extraction showed the final residue after extraction was normally the highest proportion except for Pb, for which the hydroxylamine-hydrochloride extractable Pb was the largest part. Acetic acid extractable fraction of Cd, Cu, Ni, Pb and Zn were higher in urban soils and aqua regia extractable fraction were lower suggesting an elevated availability of heavy metals in urban soils. Correlation analyses between different microbial indicators (basal respiration, biomass-C, and sole C source tests) and heavy metal fractions indicated that basal respiration was negatively correlated with soil Cd, Cu, Ni and Zn inputs while soil microbial biomass was only significantly correlated with Pb. However, both exchangeable and iron- and manganese-bound Ni fractions were mostly responsible for shift of the soil microbial community level physiological profiles (sole C source tests). These data suggest soil microbial indicators can be useful indicators of pollutant heavy metal stress on the health of urban soils.

  11. Can biochar enhance the immobilisation of heavy metals in historically contaminated soils?

    NASA Astrophysics Data System (ADS)

    Karer, Jasmin; Zehetner, Franz; Dunst, Gerald; Wagner, Mario; Puschenreiter, Markus; Friesl-Hanl, Wolfgang; Soja, Gerhard

    2014-05-01

    The location of Arnoldstein in Carinthia, Austria, is an industrial heritage site with mining and smelting activities since about 600 years. Lead and zinc ores were processed for centuries - with impacts on the surrounding soil, being polluted with heavy metals such as Cd, Pb and Zn. Up to now, the concentrations of NH4NO3-extractable heavy metals are far above the trigger values for soils (derived for feed quality according Prüeß, 1994). Cu and Ni concentrations are low and do not contribute to the heavy metal contamination of the soils. The aim of our study was to investigate the effects of various biochar mixtures on immobilisation of heavy metals in this contaminated soil. If biochar successfully immobilises heavy metals, quality of biomass production could be improved. We conducted a pot experiment with ryegrass (Lolium multiflorum) consisting of three different biochar (BC) treatments mixed with compost, a gravel sludge combined with siderite bearing material as well as a lime treatment and an untreated control (n=5). In the analysed treatments, lime significantly lowered the NH4NO3-extractable heavy metal concentrations in the soil compared to the control, except for Cu. Similarly, throughout the study, a combination of gravel sludge and siderite bearing material led to an immobilisation of the heavy metals in the soil. On the contrary, the Miscanthus biochar mixed with compost had no effect on the immobilisation; however, Cu concentration was significantly lower than in all other treatments. The immobilisation of the heavy metals in the soil was generally not reflected in the plants (Lolium multiflorum), except for Zn, showing a significant decrease after lime, poplar BC and gravel sludge with siderite bearing material. However, Zn as well as Cd and Pb remained above the phytotoxicity level of 200 mg kg-1; lime treatment reduced the Zn concentration in Lolium multiflorum to 513 mg kg-1, gravel sludge to 531 mg kg-1 and poplar BC to 560 mg kg-1 while in

  12. Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals.

    PubMed

    Hu, Pengjie; Yang, Bingfan; Dong, Changxun; Chen, Like; Cao, Xueying; Zhao, Jie; Wu, Longhua; Luo, Yongming; Christie, Peter

    2014-12-01

    The efficiency of heavy metal removal from soil by EDTA leaching was assessed in a column leaching experiment at the laboratory scale and field heap leaching at the pilot scale using a sandy loam sierozem agricultural soil contaminated with Cd, Cu, Pb, and Zn. Soil amendment and aging were conducted to recover leaching soils. The percentages of Cd, Cu, Pb, and Zn removed by column leaching were 90%, 88%, 90%, and 67%, respectively, when 3.9 bed volumes of 50mM EDTA were used. At the pilot scale, on-site metal removal efficiencies using the selected leaching procedure were 80%, 69%, 73% and 62% for Cd, Cu, Pb and Zn, respectively. EDTA leaching decreased soil CEC, total P, total K and available K concentrations but increased organic matter and total Kjeldahl N concentrations. The subsequent amendment and soil aging further reduced the DTPA-extractable heavy metals in the leached soils. Growth of the first crop of pak choi in the leached soil was inhibited but the second crop grew well after the soil was aged for one year and the concentrations of Cd and Pb in the edible parts were below the Chinese statutory limits. The results demonstrate the potential feasibility of the field leaching technique using EDTA combined with subsequent amendment and soil aging for the remediation of heavy metal-contaminated agricultural soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Heavy metals relationship in arable and greenhouse soils of SE Spain using a geostatistical analysis

    NASA Astrophysics Data System (ADS)

    Gil, Carlos; Joaquin Ramos-Miras, Jose; Rodríguez Martín, Jose Antonio; Boluda, Rafael; Roca, Núria; Bech, Jaume

    2013-04-01

    This study compares heavy metals contents and the main edaphic parameters in greenhouse soils from the W Almería region one of the most productive agricultural systems in Europe, with agricultural soils (arable soils) in western Andalusia, SW Spain. Heavy metals input in agricultural soils mainly occur through pesticides and phytosanitary control products. The hazardousness of the studied elements (Cr, Ni, Pb, Cu, Zn and Cd) is particularly relevant in soils used for intensive greenhouse farming where such agricultural practices, which centre on maximising production, end up with products that finally enter the human food chain directly. Here we explore a total of 199 greenhouse soils and 142 arable soils, representing two scales of variation in this Mediterranean area. Despite their similar edaphic characteristics, the main differences between arable soils and greenhouse soils lie in nutrients contents (P and K) and in certain heavy metals (Cd, Pb and Zn), which reflect widespread use of pesticides in greenhouse farming. One of the most toxic metals is Cd given its mobility, whose concentrations triple in greenhouse soils, although it does not exceed the limits set by Spanish legislation. We conclude that despite anthropic heavy metals input, the association patterns of these elements were similar on the two spatial variability scales. Cd, Pb and Zn contents, and partly those of Cu, are related with agricultural practices. On the short spatial scale, grouping these heavy metals shows very high contents in greenhouse soils in the central northern area of the W Almería region. On the other hand, the associations of Cr and Ni suggest a lithogenic influence combined with a pedogenic effect on spatial maps. This natural origin input becomes more marked on the long spatial scale (arable soils) where the main Cr and Ni contents are found in the vicinity of the Gádor Mountain Range.

  14. Bioaccumulative and conchological assessment of heavy metal transfer in a soil-plant-snail food chain

    PubMed Central

    2012-01-01

    Background Copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) can pose serious threats to environmental health because they tend to bioaccumulate in terrestrial ecosystems. We investigated under field conditions the transfer of these heavy metals in a soil-plant-snail food chain in Banat area, Romania. The main goal of this paper was to assess the Roman snail (Helix pomatia) usefulness in environmental monitoring as bioindicator of heavy metal accumulation. Eight sampling sites, selected by different history of heavy metal (HM) exposure, were chosen to be sampled for soil, nettle leaves, and newly matured snails. This study also aimed to identify the putative effects of HM accumulation in the environment on phenotypic variability in selected shell features, which included shell height (SH), relative shell height (RSH), and whorl number (WN). Results Significantly higher amounts of HMs were accumulated in snail hepatopancreas and not in foot. Cu, Zn, and Cd have biomagnified in the snail body, particularly in the hepatopancreas. In contrast, Pb decreased when going up into the food chain. Zn, Cd, and Pb correlated highly with each other at all levels of the investigated food chain. Zn and Pb exhibited an effective soil–plant transfer, whereas in the snail body only foot Cu concentration was correlated with that in soil. There were significant differences among sampling sites for WN, SH, and RSH when compared with reference snails. WN was strongly correlated with Cd and Pb concentrations in nettle leaves but not with Cu and Zn. SH was independent of HM concentrations in soil, snail hepatopancreas, and foot. However, SH correlated negatively with nettle leaves concentrations for each HM except Cu. In contrast, RSH correlated significantly only with Pb concentration in hepatopancreas. Conclusions The snail hepatopancreas accumulates high amounts of HMs, and therefore, this organ can function as a reliable biomarker for tracking HM bioavailability in soil. Long

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

    PubMed

    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.

  16. Soil moisture under contrasted atmospheric conditions in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Azorin-Molina, César; Cerdà, Artemi; Vicente-Serrano, Sergio M.

    2014-05-01

    Soil moisture plays a key role on the recently abandoned agriculture land where determine the recovery and the erosion rates (Cerdà, 1995), on the soil water repellency degree (Bodí et al., 2011) and on the hydrological cycle (Cerdà, 1999), the plant development (García Fayos et al., 2000) and the seasonality of the geomorphological processes (Cerdà, 2002). Moreover, Soil moisture is a key factor on the semiarid land (Ziadat and Taimeh, 2013), on the productivity of the land (Qadir et al., 2013) and soils treated with amendments (Johnston et al., 2013) and on soil reclamation on drained saline-sodic soils (Ghafoor et al., 2012). In previous study (Azorin-Molina et al., 2013) we investigated the intraannual evolution of soil moisture in soils under different land managements in the Valencia region, Eastern Spain, and concluded that soil moisture recharges are much controlled by few heavy precipitation events; 23 recharge episodes during 2012. Most of the soil moisture recharge events occurred during the autumn season under Back-Door cold front situations. Additionally, sea breeze front episodes brought isolated precipitation and moisture to mountainous areas within summer (Azorin-Molina et al., 2009). We also evidenced that the intraanual evolution of soil moisture changes are positively and significatively correlated (at p<0.01) with the amount of measured precipitation. In this study we analyze the role of other crucial atmospheric parameters (i.e., temperature, relative humidity, global solar radiation, and wind speed and wind direction) in the intraanual evolution of soil moisture; focussing our analyses on the soil moisture discharge episodes. Here we present 1-year of soil moisture measurements at two experimental sites in the Valencia region, one representing rainfed orchard typical from the Mediterranean mountains (El Teularet-Sierra de Enguera), and a second site corresponding to an irrigated orange crop (Alcoleja). Key Words: Soil Moisture Discharges

  17. Heavy Metals in Surface Soils in the Upper Reaches of the Heihe River, Northeastern Tibetan Plateau, China.

    PubMed

    Bu, Jianwei; Sun, Ziyong; Zhou, Aiguo; Xu, Youning; Ma, Rui; Wei, Wenhao; Liu, Meng

    2016-02-23

    The upper reaches of the Heihe River have been regarded as a hotspot for phytoecology, climate change, water resources and hydrology studies. Due to the cold-arid climate, high elevation, remote location and poor traffic conditions, few studies focused on heavy metal contamination of soils have been conducted or reported in this region. In the present study, an investigation was performed to provide information regarding the concentration levels, sources, spatial distributions, and environmental risks of heavy metals in this area for the first time. Fifty-six surface soil samples collected from the study area were analyzed for Cr, Mn, Ni, Cu, Zn, As, Cd and Pb concentrations, as well as TOC levels. Basic statistics, concentration comparisons, correlation coefficient analysis and multivariate analyses coupled with spatial distributions were utilized to delineate the features and the sources of different heavy metals. Risk assessments, including geoaccumulation index, enrichment factor and potential ecological risk index, were also performed. The results indicate that the concentrations of heavy metals have been increasing since the 1990 s. The mean values of each metal are all above the average background values in the Qinghai Province, Tibet, China and the world, except for that of Cr. Of special note is the concentration of Cd, which is extremely elevated compared with all background values. The distinguished ore-forming conditions and well-preserved, widely distributed limestones likely contribute to the high Cd concentration. Heavy metals in surface soils in the study area are primarily inherited from parent materials. Nonetheless, anthropogenic activities may have accelerated the process of weathering. Cd presents a high background concentration level and poses a severe environmental risk throughout the whole region. Soils in Yinda, Reshui daban, Kekeli and Zamasheng in particular pose threats to the health of the local population, as well as that of livestock

  18. Heavy Metals in Surface Soils in the Upper Reaches of the Heihe River, Northeastern Tibetan Plateau, China

    PubMed Central

    Bu, Jianwei; Sun, Ziyong; Zhou, Aiguo; Xu, Youning; Ma, Rui; Wei, Wenhao; Liu, Meng

    2016-01-01

    The upper reaches of the Heihe River have been regarded as a hotspot for phytoecology, climate change, water resources and hydrology studies. Due to the cold-arid climate, high elevation, remote location and poor traffic conditions, few studies focused on heavy metal contamination of soils have been conducted or reported in this region. In the present study, an investigation was performed to provide information regarding the concentration levels, sources, spatial distributions, and environmental risks of heavy metals in this area for the first time. Fifty-six surface soil samples collected from the study area were analyzed for Cr, Mn, Ni, Cu, Zn, As, Cd and Pb concentrations, as well as TOC levels. Basic statistics, concentration comparisons, correlation coefficient analysis and multivariate analyses coupled with spatial distributions were utilized to delineate the features and the sources of different heavy metals. Risk assessments, including geoaccumulation index, enrichment factor and potential ecological risk index, were also performed. The results indicate that the concentrations of heavy metals have been increasing since the 1990s. The mean values of each metal are all above the average background values in the Qinghai Province, Tibet, China and the world, except for that of Cr. Of special note is the concentration of Cd, which is extremely elevated compared with all background values. The distinguished ore-forming conditions and well-preserved, widely distributed limestones likely contribute to the high Cd concentration. Heavy metals in surface soils in the study area are primarily inherited from parent materials. Nonetheless, anthropogenic activities may have accelerated the process of weathering. Cd presents a high background concentration level and poses a severe environmental risk throughout the whole region. Soils in Yinda, Reshui daban, Kekeli and Zamasheng in particular pose threats to the health of the local population, as well as that of livestock

  19. Study on adsorption and remediation of heavy metals by poplar and larch in contaminated soil.

    PubMed

    Wang, Xin; Jia, Youngfeng

    2010-08-01

    Field experiments at the Shenyang Experimental Station of Ecology were conducted to study the adsorption, accumulation, and remediation of heavy metals by poplar and larch grown in artificially contaminated soil. The soil was spiked with a combination of Cd, Cu, and Zn at concentrations of 1.5, 100, and 200 mg.kg(-1), respectively. The results showed that the biomass of poplar (Populus canadensis Moench) was lower by 26.0% in the soil spiked with a mixture of Cd, Cu, and Zn, compared with the control. Concentrations of Cd in poplar leaf and Cu in poplar roots in the treated soil were 4.11 and 14.55 mg kg(-1), respectively, which are much greater than in corresponding controls. The migration of heavy metals in woody plant body was in the order Cd > Zn > Cu. Poplar had higher metal concentrations in aboveground tissues and a higher biomass compared with larch of the same age and therefore is potentially more suitable for remediation. In the heavy metal-polluted soil of this study, phytoremediation by poplar may take 56 and 245 years for Cd and Cu, respectively, for meeting the soil standards of heavy metals, and the corresponding phytoremediation times by larch would take 211 and 438 years. The research findings could be used as a basis to develop ecological engineering technologies for environmental control and remediation of pollution caused by heavy metals in soils.

  20. Heavy metal balances of an Italian soil as affected by sewage sludge and Bordeaux mixture applications

    SciTech Connect

    Moolenaar, S.W.; Beltrami, P.

    1998-07-01

    Applications of sewage sludge and Bordeaux mixture (Bm) (a mixture of copper sulfate and lime) add heavy metals to the soil. At an experimental farm in the Cremona district (Italy), the authors measured current heavy metal contents in soil and their removal via harvested products. They also measured heavy metal adsorption by soil from this farm. With these data, projections were made of the long-term development of heavy metal (Cd, Cu, and Zn) contents in soil, crop removal, and leaching at different application rates of sewage sludge and Bm. These projections were compared with existing quality standards of the European Union (EU) and Italy with regard to soil and groundwater. The calculations reveal that the permitted annual application rates of sewage sludge and Bm are likely to result in exceedance of groundwater and soil standards. Sewage sludge applications, complying with the Italian legal limits, may pose problems for Cd, Cu, and Zn within 30, 70, and 100 yr, respectively. Furthermore, severe Cu pollution of integrated and especially organic (Bm only) vineyards is unavoidable with the currently allowed application rates of Bm. The results suggest that the current Italian soil protection policy as well as the EU policy are not conducive of a sustainable heavy metal management in agroecosystems.

  1. [Effects of Tillage on Distribution of Heavy Metals and Organic Matter Within Purple Paddy Soil Aggregates].

    PubMed

    Shi, Qiong-bin; Zhao, Xiu-lan; Chang, Tong-ju; Lu, Ji-wen

    2016-05-15

    A long-term experiment was utilized to study the effects of tillage methods on the contents and distribution characteristics of organic matter and heavy metals (Cu, Zn, Pb, Cd, Fe and Mn) in aggregates with different sizes (including 1-2, 0.25-1, 0.05-0.25 mm and < 0.05 mm) in a purple paddy soil under two tillage methods including flooded paddy field (FPF) and paddy-upland rotation (PR). The relationship between heavy metals and organic matter in soil aggregates was also analyzed. The results showed that the aggregates of two tillage methods were dominated by 0.05-0.25 mm and < 0.05 mm particle size, respectively. The contents of organic matter in each aggregate decreased with the decrease of aggregate sizes, however, compared to PR, FPF could significantly increase the contents of organic matter in soils and aggregates. The tillage methods did not significantly affect the contents of heavy metals in soils, but FPF could enhance the accumulation and distribution of aggregate, organic matter and heavy metals in aggregates with diameters of 1-2 mm and 0.25-1 mm. Correlation analysis found that there was a negative correlation between the contents of heavy metals and organic matter in soil aggregates, but a positive correlation between the amounts of heavy metal and organic matter accumulated in soil aggregates. From the slope of the correlation analysis equations, we could found that the sensitivities of heavy metals to the changes of soil organic matters followed the order of Mn > Zn > Pb > Cu > Fe > Cd under the same tillage. When it came to the same heavy metal, it was more sensitive in PR than in FPF.

  2. Heavy metal accumulation in balsam pear and cowpea related to the geochemical factors of variable-charge soils in the Pearl River Delta, South China.

    PubMed

    Chang, Chun-Ying; Xu, Xiang-Hua; Liu, Chuan-Ping; Li, Shu-Yi; Liao, Xin-Rong; Dong, Jun; Li, Fang-Bai

    2014-07-01

    Variable-charge (v-c) soils in subtropical areas contain considerable amounts of iron/aluminum (Fe/Al) oxides that can strongly influence the fate of heavy metals in agricultural ecosystems. However, the relationship between heavy metal accumulation in vegetables and the geochemical factors associated with v-c soils in subtropical regions remains unknown. The present study investigated heavy metal accumulation under field conditions in the Pearl River Delta (PRD) by measuring the content of 8 heavy metals (zinc (Zn), arsenic (As), copper (Cu), mercury (Hg), lead (Pb), chromium (Cr), nickel (Ni) and cadmium (Cd)) in 43 pairs of v-c soil and vegetable (balsam pear and cowpea) samples. Soil physicochemical properties including pH, texture, organic matter and oxide minerals (Fe2O3, SiO2, Al2O3, CaO, MgO, K2O and Na2O) were also analyzed. Heavy metal accumulation from soil to vegetables was assessed based on bioconcentration factors (BCFs). The results showed that soil extractable Fe, oxide minerals and chemical weathering indices of v-c soils strongly affected heavy metal accumulation, whereas the content of Zn, Cu, Cr and Ni in vegetables was strongly affected by the soil clay content. Significant correlations were found between the BCFs of heavy metals and oxide minerals. However, no significant relationship was found between pH and heavy metal accumulation (except for Cu) in balsam pear and cowpea. Correlation analyses showed that a lower oxalate/DCB- extractable Fe content might indicate greater heavy metal (Zn, Cu, Hg, Cr and Ni) accumulation in vegetables. Therefore, it can be deduced that oxalate/DCB- extractable Fe content is a critical geochemical factor that determines the bioavailability of heavy metals and that iron biogeochemical cycles play vital roles in the fate of heavy metals in vegetable fields in this area. These findings provide new insights into the behaviors and fate of heavy metals in subtropical v-c soils and can be used to develop possible

  3. Biochar-attenuated desorption of heavy metals in small arms range soils

    USDA-ARS?s Scientific Manuscript database

    Stabilization (capping/solidification) and dilution (e.g., washing, chelate-assisted phytoremediation) represent non-removal and removal remediation technologies for heavy metal contaminated soils. Biochar is stable in soil, and contains carboxyl and other surface ligands; these properties are usef...

  4. The effects of the Qinghai-Tibet railway on heavy metals enrichment in soils.

    PubMed

    Zhang, Hua; Wang, Zhaofeng; Zhang, Yili; Hu, Zhongjun

    2012-11-15

    The impact of land transportation on local soil environments is an important topic in environmental and ecological sciences. The rapid development of transportation infrastructure lends increasing importance to studies that identify and evaluate related heavy metal pollution. This paper discusses the effects of railways on soil heavy metal enrichments in the Tibetan plateau. At a representative area along the Haergai-Delingha railway, lead, cadmium, copper, zinc, chromium, nickel, cobalt, and vanadium were measured in 127 topsoil samples (0-10 cm depth). The results indicate that railway transport has a significant effect on the concentration of Zn, Cd and Pb in the soil, with levels of enrichment ranging from no pollution to significant pollution. The affected area was within 20 m of the railway. The soil at Delingha was the most contaminated soil with heavy metals, and the enrichment level of Cd in the soil was the highest along the Qinghai-Tibet railway. The horizontal distributions of the three heavy metals present different characteristics at different sampling sites, which may be due to discrepancies in terrain and vegetation types. Alkaline soils and guardrails along the railway might reduce the effect of soil pollution on local people and animals.

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

    USDA-ARS?s Scientific Manuscript database

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

  6. Phytoremediation of heavy metal-contaminated soils: natural hyperaccumulation versus chemically enhanced phytoextraction.

    PubMed

    Lombi, E; Zhao, F J; Dunham, S J; McGrath, S P

    2001-01-01

    A pot experiment was conducted to compare two strategies of phytoremediation: natural phytoextraction using the Zn and Cd hyperaccumulator Thlaspi caerulescens J. Presl & C. Presl versus chemically enhanced phytoextraction using maize (Zea mays L.) treated with ethylenediaminetetraacetic acid (EDTA). The study used an industrially contaminated soil and an agricultural soil contaminated with metals from sewage sludge. Three crops of T. caerulescens grown over 391 d removed more than 8 mg kg(-1) Cd and 200 mg kg(-1) Zn from the industrially contaminated soil, representing 43 and 7% of the two metals in the soil. In contrast, the high concentration of Cu in the agricultural soil severely reduced the growth of T. caerulescens, thus limiting its phytoextraction potential. The EDTA treatment greatly increased the solubility of heavy metals in both soils, but this did not result in a large increase in metal concentrations in the maize shoots. Phytoextraction of Cd and Zn by maize + EDTA was much smaller than that by T. caerulescens from the industrially contaminated soil, and was either smaller (Cd) or similar (Zn) from the agricultural soil. After EDTA treatment, soluble heavy metals in soil pore water occurred mainly as metal-EDTA complexes, which were persistent for several weeks. High concentrations of heavy metals in soil pore water after EDTA treatment could pose an environmental risk in the form of ground water contamination.

  7. Utilization of a duckweed bioassay to evaluate leaching of heavy metals in smelter contaminated soils

    SciTech Connect

    Youngman, A.L.; Lydy, M.J.; Williams, T.L.

    1998-12-31

    The purpose of this study was to determine whether a duckweed bioassay could be used to evaluate the downward migration of heavy metals in smelter soils. The duckweed bioassay was initially used to evaluate elutriates prepared from samples of smelter soils. These initial tests verified that the elutriates would elicit toxic responses. Elutriate testing was followed with an evaluation of leachate from untreated soil cores or soil cores that had been amended with organic matter either unplanted or planted to a grass-forb seed mixture. There was an inverse linear relationship between heavy-metal concentrations in leachate and NOEC and IC{sub 50} values expressed as percentages among all soil cores. Based on these preliminary duckweed bioassays, there were no differences between soil types or organic amended or non-amended soil, but leachate from vegetated soil cores were less toxic than were leachates from non-vegetated soil cores. Overall, the duckweed bioassays were useful in detecting heavy metal availability in elutriate and leachate samples from smelter soils.

  8. Soil quality changes in response to their pollution by heavy metals, Georgia.

    PubMed

    Matchavariani, Lia; Kalandadze, Besik; Lagidze, Lamzira; Gokhelashvili, Nino; Sulkhanishvili, Nino; Paichadze, Nino; Dvalashvili, Giorgi

    2015-01-01

    The present study deals with the composition, migration and accumulation of heavy metals in irrigated soils, plants and partially natural waters; and also, establishing the possible sources of pollution and their impact on environmental situation. The content of toxic elements in the irrigated soils adjacent to ore mining and processing enterprise were studied. Content of toxic elements in the irrigated soils adjacent to ore mining, showed that more than half of territory was seriously polluted by copper and zinc. Some part of the area were considered catastrophically polluted. Expressed technogenesis taking place influenced irrigation. Heavy metals like copper, zinc and manganese negative by effected the properties of soil, thus composition and soil-forming processes taking place in the soil. It was especially well represented in the deterioration of hydro-physical potential of the soil. Irrigation of agricultural land plots by water, polluted with heavy metals changed the pH. Balanced correlation among solid, liquid and gas phases was disrupted. In highly polluted soil, the cementing processes took place that sharply increased the bulk density of the soil, deteriorated the porosity of soil and reduced water permeability critically.

  9. Occurrences and toxicological risk assessment of eight heavy metals in agricultural soils from Kenya, Eastern Africa.

    PubMed

    Mungai, Teresiah Muciku; Owino, Anita Awino; Makokha, Victorine Anyango; Gao, Yan; Yan, Xue; Wang, Jun

    2016-09-01

    The concentration distribution and toxicological assessment of eight heavy metals including lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), mercury (Hg), arsenic (As), and zinc (Zn) in agricultural soils from Kenya, Eastern Africa, were investigated in this study. The results showed mean concentrations of eight heavy metals of Zn, Pb, Cr, Cu, As, Ni, Hg, and Cd in agricultural soils as 247.39, 26.87, 59.69, 88.59, 8.93, 12.56, 8.06, and 0.42 mg kg(-1), respectively. These mean values of eight heavy metals were close to the toxicity threshold limit of USEPA standard values of agricultural soils, indicating potential toxicological risk to the food chain. Pollution index values revealed that eight heavy metals severely decreased in the order Hg > Cd > As > Cu > Pb > Zn > Ni > Cr and the mean value of the overall pollution index of Hg and Cd was 20.31, indicating severe agriculture ecological risk. Potential pollution sources of eight heavy metals in agricultural soils were mainly from anthropogenic activities and natural dissolution. The intensification of human agricultural activities, the growing industrialization, and the rapid urbanization largely influenced the concentration levels of heavy metals in Kenya, Eastern Africa. Moreover, the lack of agricultural normalization management and poor enforcement of environmental laws and regulations further intensified the widespread pollution of agricultural soils in Kenya.

  10. Improvement of soil quality after "alperujo" compost application to two contaminated soils characterised by differing heavy metal solubility.

    PubMed

    Alburquerque, J A; de la Fuente, C; Bernal, M P

    2011-03-01

    Reclamation of trace element polluted soils often requires the improvement of the soil quality by using appropriate organic amendments. Low quality compost from municipal solid waste has been tested for reclamation of soils, but these materials can provide high amounts of heavy metals. Therefore, a high-quality compost, with low levels of heavy metals, produced from the main by-product of the Spanish olive oil extraction industry ("alperujo") was evaluated for remediation of soils affected by a pyritic mine sludge. Two contaminated soils were selected from the same area: they were characterised by differing pH values (4.6 and 7.3) and total metal concentrations, which greatly affected the fractionation of the metals. Compost was applied to soil at two rates (equivalent to 48 and 72 Tm ha(-1)) and compared with an inorganic fertiliser treatment. Compost acted as an available nutrient source (C, N and P) and showed a low mineralisation rate, suggesting a slow release of nutrients and thus favouring long term soil fertility. In addition, the liming effect of the compost led to a significant reduction of toxicity for soil microorganisms in the acidic soil and immobilisation of soil heavy metals (especially Mn and Zn), resulting in a clear increase in both soil microbial biomass and nitrification. Such positive effects were clearly greater than those provoked by the mineral fertiliser even at the lowest compost application rate, which indicates that this type of compost can be very useful for bioremediation programmes (reclamation and revegetation of polluted soils) based on phytostabilisation strategies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Dynamism of PGPR in bioremediation and plant growth promotion in heavy metal contaminated soil.

    PubMed

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

    2016-04-01

    Heavy metal contamination, particularly of cultivable lands, is a matter of concern. Bioremediation helps in reversing such contamination to certain extent. Here, we report isolation, polyphasic identification and the role of siderophore producing rhizobacteria Alcaligenes feacalis RZS2 and Pseudomonas aeruginosa RZS3 in bioremediation of heavy metal contaminated soil and plant growth promotion activity in such contaminated soil. Siderophore produced by A. feacalis RZS2 and P. aeruginosa RZS3 strains chelated various heavy metal ions like MnCl₂.4H₂O, NiCl₂.6H₂O, ZnCl₂, CuCl₂ and CoCl₂ other than FeCl₃.6H2O at batch scale. Their bioremediation potential was superior over the chemical ion chelators like EDTA and citric acid. These isolates also promoted growth of wheat and peanut seeds sown in heavy metal contaminated soil. Effective root colonizing ability of these isolates was observed in wheat and peanut plants.

  12. Use of phytoremediation and biochar to remediate heavy metal polluted soils: a review

    NASA Astrophysics Data System (ADS)

    Paz-Ferreiro, J.; Lu, H.; Fu, S.; Méndez, A.; Gascó, G.

    2014-02-01

    Anthropogenic activities are resulting in an increase of the use and extraction of heavy metals. Heavy metals cannot be degraded and hence accumulate in the environment, having the potential to contaminate the food chain. This pollution threatens soil quality, plant survival and human health. The remediation of heavy metals deserves attention, but it is impaired by the cost of these processes. Phytoremediation and biochar are two sound environmental technologies which could be at the forefront to mitigate soil pollution. This review provides an overview of the state of the art of the scientific research on phytoremediation and biochar application to remediate heavy-metal-contaminated soils. Research to date has attempted only in a limited number of occasions to combine both techniques, however we discuss the potential advantages of combining both, and the potential mechanisms involved in the interaction between phytoremediators and biochar. We identified specific research needs to ensure a sustainable use of phytoremediation and biochar as remediation tools.

  13. Survey of heavy metal pollution in four chinese crude drugs and their cultivated soils.

    PubMed

    Wu, Jialun; Zou, Yaohua; Zhan, Xiuping; Chen, Shifei; Lu, Guangzhao; Lai, Fugen

    2008-12-01

    A two-year survey on the residues of heavy metals in four Chinese crude drugs and their cultivated soils was conducted. Targeted heavy metals were copper (Cu), arsenic (As), lead (Pb), nickel (Ni), and cadmium (Cd). Herbs surveyed include White Peony Root (Radix Paeoniae Alba), Turmeric Root Tuber (Radix Curcumae), Thunberg Fritillary Bulb (Bulbus Fritillariae Thumbergii), and Tuber of Dwarf Lilyturf (Radix Ophiopogonis). Concentrations of all heavy metals were under the permitted levels except cadmium, which exceeded the permitted level in some samples of Thunberg Fritillary Bulb, White Peony Root, and Turmeric Root Tuber. Concentration coefficients were less than 1.0 for all heavy metals except cadmium. The concentration coefficient of cadmium in Turmeric Root Tuber was 14.0. Lower pH and high Zn concentration in the soil may facilitate the transfer of cadmium from cultivated soil into the herbs.

  14. Application of stochastic models in identification and apportionment of heavy metal pollution sources in the surface soils of a large-scale region.

    PubMed

    Hu, Yuanan; Cheng, Hefa

    2013-04-16

    As heavy metals occur naturally in soils at measurable concentrations and their natural background contents have significant spatial variations, identification and apportionment of heavy metal pollution sources across large-scale regions is a challenging task. Stochastic models, including the recently developed conditional inference tree (CIT) and the finite mixture distribution model (FMDM), were applied to identify the sources of heavy metals found in the surface soils of the Pearl River Delta, China, and to apportion the contributions from natural background and human activities. Regression trees were successfully developed for the concentrations of Cd, Cu, Zn, Pb, Cr, Ni, As, and Hg in 227 soil samples from a region of over 7.2 × 10(4) km(2) based on seven specific predictors relevant to the source and behavior of heavy metals: land use, soil type, soil organic carbon content, population density, gross domestic product per capita, and the lengths and classes of the roads surrounding the sampling sites. The CIT and FMDM results consistently indicate that Cd, Zn, Cu, Pb, and Cr in the surface soils of the PRD were contributed largely by anthropogenic sources, whereas As, Ni, and Hg in the surface soils mostly originated from the soil parent materials.

  15. Comparison of heavy metals and uranium removal using adsorbent in soil

    NASA Astrophysics Data System (ADS)

    Choi, Jaeyoung; Yun, Hunsik

    2017-04-01

    This study investigates heavy metals (As, Ni, Zn, Cd, and Pb) and uranium removal onto geomaterials (limestone, black shale, and concrete) and biosorbents (Pseudomonas putida and starfish) from waste in soil. Geomaterials or biosorbents with a high capacity for heavy metals and uranium can be obtained and employed of with little cost. For investigating the neutralization capacity, the change in pH, Eh, and EC as a function of time was quantified. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing heavy metals and uranium concentrations. Dead cells adsorbed the largest quantity of all heavy metals than lother sorbents. The adsorption capacity followed the order: U(VI) > Pb > Cd > Ni. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated soil.

  16. Distribution and source apportionment studies of heavy metals in soil of cotton/wheat fields.

    PubMed

    Rafique, Nazia; Tariq, Saadia R

    2016-05-01

    Heavy metals enriched agricultural soils have been the subject of great concern because these metals have potential to be transferred to the soil solution and afterward accumulated in food chain. To study the trace metal persistence in crop soil, 90 representative soil samples were collected and analyzed for heavy metal (As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn) and anions (chloride, nitrates, phosphates and sulfates). Cluster and factor analysis techniques were used for the source identification of these excessive heavy metal levels and ecological risk was determined with potential ecological risk assessment. The degree of enrichment of eight studied heavy metals in comparison with the corresponding background levels decreased in order: Cd > Pb > Fe > Ni > Mn > As > Cu ~ Zn. Arsenic and cadmium exhibited 1.30- and 1.64-fold exceeded levels than threshold limits set by National environment quality standards, respectively. Cd in cotton field's soil may lead to higher potential risk than other heavy metals. On overall basis, the cumulative mean potential ecological risk for the district (207.75) corresponded to moderate risk level with higher contributions from As and Pb especially from Cd. Cadmium formed strong positive correlation with phosphate content of soil at p < 0.01. Cluster analysis indicated that Cluster 1 (extremely polluted) probably originated from anthropogenic inputs of phosphate fertilizer and past usage of arsenical pesticides.

  17. Heavy metal concentrations in roadside soils and correlation with urban traffic in Beijing, China.

    PubMed

    Chen, Xi; Xia, Xinghui; Zhao, Ye; Zhang, Ping

    2010-09-15

    A detailed investigation was conducted to study the heavy metal concentrations in roadside soils of Beijing. The concentrations of Cd, Cu, Pb and Zn showed a decreasing trend with increasing distance from the road while such trend was not identified in As, Cr and Ni. In addition, the concentrations of Cd, Cu, Pb and Zn significantly positively correlated with black carbon (BC) and TOC (p<0.01). The soil samples from West 2nd Ring Road with the highest traffic volume had the highest heavy metal concentrations of the 10 roads, and Pb concentration was significantly positively correlated with traffic volumes (p<0.05). According to the soil guideline values of China, Cd was considered to have considerable contamination in roadside soils, while Cu, Pb and Zn less, but As, Ni, Cr none. The concentrations of heavy metals in roadside soils of Beijing were considered medium or low in comparison with those in other cities; this may be due to the windy and dry climate in Beijing. The heavy metals could move with wind along the wind direction and the soil samples had higher heavy metal concentrations at the downwind direction. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Effects of biochars on the availability of heavy metals to ryegrass in an alkaline contaminated soil.

    PubMed

    Zhang, Guixiang; Guo, Xiaofang; Zhao, Zhihua; He, Qiusheng; Wang, Shuifeng; Zhu, Yuen; Yan, Yulong; Liu, Xitao; Sun, Ke; Zhao, Ye; Qian, Tianwei

    2016-11-01

    A pot experiment was conducted to investigate the effects of biochars on the availability of heavy metals (Cd, Cu, Mn, Ni, Pb, and Zn) to ryegrass in an alkaline contaminated soil. Biochars only slightly decreased or even increased the availability of heavy metals assesses by chemical extractant (a mixture of 0.05 mol L(-1) ethylenediaminetetraacetic acid disodium, 0.01 mol L(-1) CaCl2, and 0.1 mol L(-1) triethanolamine). The significantly positive correlation between most chemical-extractable heavy metals and the ash content in biochars indicated the positive role of ash in this extraction. Biochars significantly reduced the plant uptake of heavy metals, excluding Mn. The absence of a positive correlation between the chemical-extractable heavy metals and the plant uptake counterparts (except for Mn) indicates that chemical extractability is probably not a reliable indicator to predict the phytoavailability of most heavy metals in alkaline soils treated with biochars. The obviously negative correlation between the plant uptake of heavy metals (except for Mn) and the (O + N)/C and H/C indicates that biochars with more polar groups, which were produced at lower temperatures, had higher efficiency for reducing the phytoavailability of heavy metals. The significantly negative correlations between the plant uptake of Mn and ryegrass biomass indicated the "dilution effect" caused by the improvement of biomass. These observations will be helpful for designing biochars as soil amendments to reduce the availability of heavy metals to plants in soils, especially in alkaline soils. Copyright © 2016. Published by Elsevier Ltd.

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

    SciTech Connect

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

    1994-12-01

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

  20. Interaction of Soil Heavy Metal Pollution with Industrialisation and the Landscape Pattern in Taiyuan City, China

    PubMed Central

    Liu, Yong; Su, Chao; Zhang, Hong; Li, Xiaoting; Pei, Jingfei

    2014-01-01

    Many studies indicated that industrialization and urbanization caused serious soil heavy metal pollution from industrialized age. However, fewer previous studies have conducted a combined analysis of the landscape pattern, urbanization, industrialization, and heavy metal pollution. This paper was aimed at exploring the relationships of heavy metals in the soil (Pb, Cu, Ni, As, Cd, Cr, Hg, and Zn) with landscape pattern, industrialisation, urbanisation in Taiyuan city using multivariate analysis. The multivariate analysis included correlation analysis, analysis of variance (ANOVA), independent-sample T test, and principal component analysis (PCA). Geographic information system (GIS) was also applied to determine the spatial distribution of the heavy metals. The spatial distribution maps showed that the heavy metal pollution of the soil was more serious in the centre of the study area. The results of the multivariate analysis indicated that the correlations among heavy metals were significant, and industrialisation could significantly affect the concentrations of some heavy metals. Landscape diversity showed a significant negative correlation with the heavy metal concentrations. The PCA showed that a two-factor model for heavy metal pollution, industrialisation, and the landscape pattern could effectively demonstrate the relationships between these variables. The model explained 86.71% of the total variance of the data. Moreover, the first factor was mainly loaded with the comprehensive pollution index (P), and the second factor was primarily loaded with landscape diversity and dominance (H and D). An ordination of 80 samples could show the pollution pattern of all the samples. The results revealed that local industrialisation caused heavy metal pollution of the soil, but such pollution could respond negatively to the landscape pattern. The results of the study could provide a basis for agricultural, suburban, and urban planning. PMID:25251460

  1. Interaction of soil heavy metal pollution with industrialisation and the landscape pattern in Taiyuan city, China.

    PubMed

    Liu, Yong; Su, Chao; Zhang, Hong; Li, Xiaoting; Pei, Jingfei

    2014-01-01

    Many studies indicated that industrialization and urbanization caused serious soil heavy metal pollution from industrialized age. However, fewer previous studies have conducted a combined analysis of the landscape pattern, urbanization, industrialization, and heavy metal pollution. This paper was aimed at exploring the relationships of heavy metals in the soil (Pb, Cu, Ni, As, Cd, Cr, Hg, and Zn) with landscape pattern, industrialisation, urbanisation in Taiyuan city using multivariate analysis. The multivariate analysis included correlation analysis, analysis of variance (ANOVA), independent-sample T test, and principal component analysis (PCA). Geographic information system (GIS) was also applied to determine the spatial distribution of the heavy metals. The spatial distribution maps showed that the heavy metal pollution of the soil was more serious in the centre of the study area. The results of the multivariate analysis indicated that the correlations among heavy metals were significant, and industrialisation could significantly affect the concentrations of some heavy metals. Landscape diversity showed a significant negative correlation with the heavy metal concentrations. The PCA showed that a two-factor model for heavy metal pollution, industrialisation, and the landscape pattern could effectively demonstrate the relationships between these variables. The model explained 86.71% of the total variance of the data. Moreover, the first factor was mainly loaded with the comprehensive pollution index (P), and the second factor was primarily loaded with landscape diversity and dominance (H and D). An ordination of 80 samples could show the pollution pattern of all the samples. The results revealed that local industrialisation caused heavy metal pollution of the soil, but such pollution could respond negatively to the landscape pattern. The results of the study could provide a basis for agricultural, suburban, and urban planning.

  2. Phytomining of heavy metals from soil by Croton bonplandianum using phytoremediation technology

    NASA Astrophysics Data System (ADS)

    Panchal, K. J.; Dave, B. R.; Parmar, P. P.; Subramanian, R. B.

    2015-12-01

    Metal ions are not only valuable intermediates in metal extraction, but also important raw materials for technical applications. They possess some unique but, identical physical and chemical properties, which make them useful probes of low temperature geochemical reactions. Heavy metals are natural constituents of the earth's crust, but indiscriminate human activities have drastically altered their geochemical cycles and biochemical balance. Metal concentration in soil typically ranges from less than one to as high as 100,000 mg/kg. Heavy metal contaminations of land resources continue to be the focus of numerous environmental studies and attract a great deal of attention worldwide. This is attributed to no--biodegradability and persistence of heavy metals in soils. Prolonged exposure to heavy metals such as cadmium, copper, lead, nickel, and zinc can cause deleterious health effects in humans. Complexation, separation, and removal of metal ions have become increasingly attractive areas of research and have led to new technical developments like phytoremediation that has numerous biotechnological implications of understanding of plant metal accumulation. Croton bonplandianum is newly identified as a potential heavy metal hypreaccumulator. In this study Croton bonplandianum was subjected for in vitro heavy metal accumulation, to explore the accumulation pattern of four heavy metals viz Cadmium, Lead, Nickel and Zinc in various parts of Croton bonplandianum plant parts. It was found that the efficiency of Croton bonplandianum to accumulate heavy metals is Cd>Pb>Zn>Ni. The absorption of these heavy metals in plant parts revealed that the highest translocation of metals from ground to root was ground to be in the order of Pb (1.12) > Zn (0.26) > Ni (0.18) > Cd (0.15). The distribution of Cd in Croton bonplandianum followed the trend Root>Stem>Leaf; with Ni it was Root>Leaf>Stem, while Pb showed leaf>stem>root. Translocation of metals in Croton bonplandianum plant parts

  3. [Impact of heavy metals pollution on the community structure and spatial distribution of soil animals].

    PubMed

    Sun, Xian-Bin; Liu, Hong-Yu; Li, Yu-Cheng; Zhang, Xiao-Ping

    2007-09-01

    By sampling at 8 plots surrounding the coal-mining and coal-ash areas in Huannan City of Anhui Province, a total of 3859 individuals of soil macro-, meso-, and micro-fauna belonging to 22 groups, 9 classes and 4 phyla were collected. The dominant groups were Collembola, Acarina and Nematoda, accounting for 74% of the total, and the others were frequent and rare groups. Heavy metals pollution had powerful impact on soil animals. The individual numbers and groups of soil animals declined with the aggravation of heavy metals pollution from out of the dam site to the nearing site of coal-ash area in Luohe Power Plant, and showed an abnormal distribution or little change in vertical and disappeared in surface layer. The heavy metals pollution resulted in a decline in the diversity index, evenness and density-group index, but a rise in the dominance index of soil animals.

  4. Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil.

    PubMed

    Wang, Qing-Ren; Li, Yun-Cong; Klassen, Waldemar

    2003-11-01

    The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop

  5. REDOX manipulation to enhance chelant extraction of heavy metals from contaminated soils

    SciTech Connect

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

    1995-12-31

    J-Field on the Gunpowder Neck Peninsula at the Aberdeen Proving Ground has contamination resulting from past field activities at the facility. Disposal operations conducted in this region include: toxic burning pits, white phosphorus burning pits, riot control burning pits, South Beach, Demolition Ground, South Beach trench, Robins Point Demolition Ground, Robins Point Tower Site, and the Ruins Site. Argonne National Laboratory is conducting a Focused Feasibility Study (FFS) to identify and evaluate remedial technologies that may be implemented to address contamination at the Toxic Burning Pits (TBP) area at J-Field, Aberdeen Proving Ground, Maryland. As part of the FFS, several treatability studies were performed to collect additional data on potential technologies and determine their applicability on conditions specific to the TBP area. This paper summarizes the results soil washing and enhancements to soil washing portions of the study. On the basis of their concentrations in the untreated TBP soils and degree of environmental impact, the primary heavy metals of concern for the FFS were copper, lead, and zinc.

  6. Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana

    PubMed Central

    Bortey-Sam, Nesta; Nakayama, Shouta M. M.; Akoto, Osei; Ikenaka, Yoshinori; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-01-01

    Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (Cdeg) in some communities such as, Wangarakrom (11), Badukrom (13) and T–Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (Cif), Cdeg, monomial ecological risk (Eir) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role. PMID:26378563

  7. [Effect of Recycled Water Irrieation on Heavy Metal Pollution in Irrigation Soil].

    PubMed

    Zhou, Yi-qi; Liu, Yun-xia; Fu, Hui-min

    2016-01-15

    With acceleration of urbanization, water shortages will become a serious problem. Usage of reclaimed water for flushing and watering of the green areas will be common in the future. To study the heavy metal contamination of soils after green area irrigation using recycled wastewater from special industries, we selected sewage and laboratory wastewater as water source for integrated oxidation ditch treatment, and the effluent was used as irrigation water of the green area. The irrigation units included broad-leaved forest, bush and lawn. Six samples sites were selected, and 0-20 cm soil of them were collected. Analysis of the heavy metals including Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the soil showed no significant differences with heavy metals concentration in soil irrigated with tap water. The heavy metals in the soil irrigated with recycled water were mainly enriched in the surface layer, among which the contents of Cr, Ni, Cu, Zn and Pb were below the soil background values of Beijing. A slight pollution of As and Cd was found in the soil irrigated by recycled water, which needs to be noticed.

  8. Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana.

    PubMed

    Bortey-Sam, Nesta; Nakayama, Shouta M M; Akoto, Osei; Ikenaka, Yoshinori; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-09-11

    Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (C(deg)) in some communities such as, Wangarakrom (11), Badukrom (13) and T-Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (C(i)(f)), C(deg), monomial ecological risk (E(i)(r)) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role.

  9. Distribution, bioavailability, and leachability of heavy metals in soil particle size fractions of urban soils (northeastern China).

    PubMed

    Yutong, Zong; Qing, Xiao; Shenggao, Lu

    2016-07-01

    This study examines the distribution, mobility, and potential environmental risks of heavy metals in various particle size fractions of urban soils. Representative urban topsoils (ten) collected from Anshan, Liaoning (northeastern China), were separated into six particle size fractions and their heavy metal contents (Cr, Cu, Cd, Pb, and Zn) were determined. The bioaccessibility and leachability of heavy metals in particle size fractions were evaluated using the toxicity characteristic leaching procedure (TCLP) and ethylenediaminetetraacetic acid (EDTA) extraction, respectively. The results indicated that the contents of five heavy metals (Cd, Cr, Cu, Pb and Zn) in the size fractions increased with the decrease of particle size. The clay fraction of <2 μm had the highest content of heavy metals, indicating that the clay fraction was polluted by heavy metals more seriously than the other size fractions in urban topsoils. Cr also concentrated in the coarse fraction of 2000-1000 μm, indicating a lithogenic contribution. However, the dominant size fraction responsible for heavy metal accumulation appeared to belong to particle fraction of 50-2 μm. The lowest distribution factors (DFs) of heavy metals were recorded in the 2000- to 1000-μm size fraction, while the highest in the clay fraction. The DFs of heavy metals in the clay fraction followed Zn (3.22) > Cu (2.84) > Pb (2.61) > Cr (2.19) > Cd (2.05). The enrichment factor suggested that the enrichment degree of heavy metal increased with the decrease of the particle size, especially for Cd and Zn. The TCLP- and EDTA-extractable concentrations of heavy metals in the clay fraction were relatively higher than those in coarse particles. Cd bioavailability was higher in the clay fraction than in other fractions or whole soils. In contrast, Cr exhibits similar bioaccessibilities in the six size fractions of soils. The results suggested that fine particles were the main sources of potentially toxic

  10. Galena weathering under simulated calcareous soil conditions.

    PubMed

    Lara, René H; Briones, Roberto; Monroy, Marcos G; Mullet, Martine; Humbert, Bernard; Dossot, Manuel; Naja, Ghinwa M; Cruz, Roel

    2011-09-01

    Exploitation of polymetallic deposits from calcareous mining sites exposes galena and others sulfides to weathering factors. Galena weathering leads to the formation of lead phases (e.g., PbSO(4), PbCO(3)) with a higher bioaccessibility than galena, thus increasing the mobility and toxicity of lead. Despite the environmental impacts of these lead phases, the mechanisms of galena oxidation and the transformation of lead secondary phases, under neutral-alkaline carbonated conditions, have rarely been studied. In this work, an experimental approach, combining electrochemical and spectroscopic techniques, was developed to examine the interfacial processes involved in the galena weathering under simulated calcareous conditions. The results showed an initial oxidation stage with the formation of an anglesite-like phase leading to the partial mineral passivation. Under neutral-alkaline carbonated conditions, the stability of this phase was limited as it transformed into a cerussite-like one. Based on the surface characterization and the formation of secondary species, the weathering mechanisms of galena in calcareous soil and its environmental implications were suggested.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  12. Heavy metal speciation and risk assessment in dry land and paddy soils near mining areas at Southern China.

    PubMed

    Liu, Guannan; Wang, Juan; Zhang, Erxi; Hou, Jing; Liu, Xinhui

    2016-05-01

    Heavy metal contamination of soils has been a long-standing environmental problem in many parts of the world, and poses enormous threats to ecosystem and human health. Speciation of heavy metals in soils is crucial to assessing environmental risks from contaminated soils. In this study, total concentrations and speciation of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn were measured for agricultural soils near mines along the Diaojiang River in Guangxi Zhuang Autonomy Region, China. The sources of heavy metals in soils also were identified to assess their effect on speciation distribution of soil heavy metals. Furthermore, the speciation distribution of Cd and Zn, main soil heavy metal pollutants, in dry land and paddy soils were compared. Results showed that there were two severely polluted regions near mine area reaching alarming pollution level. As, Cd, Pb, and Zn were more affected by mining activities, showing very strong pollution level in soils. The mean percentage of exchangeable and carbonate fraction was highest and up to 46.8 % for Cd, indicating a high environmental risk. Greater bioavailable fractions of As, Cd, Cu, Mn, Pb, and Zn were found in soils heavily polluted by mining activities, whereas Cr and Ni as geogenic elements in the stable residual fraction. In addition, in the dry land soils, reducible fraction proportion of Cd was higher than that in the paddy soils, whereas exchangeable and carbonate fraction of Cd was lower than that in the paddy soils. Oxidizable fraction of Zn was higher in the paddy soils than that in the dry land soils. The results indicate that the sources of soil heavy metals and land types affect heavy metal speciation in the soil and are significant for environmental risk assessment of soil heavy metal pollutions.

  13. Soil-plant abstract of heavy metals in Pb-Zn mining sites from Alcudia Valley (South Spain)

    NASA Astrophysics Data System (ADS)

    López-Berdonces, Miguel; Higueras, Pablo; Esbrí, Jose Maria; González-Corrochano, Beatríz; García-Noguero, Eva Mª; Martínez-Coronado, Alba; Fernandez-Calderón, Sergio; García-Noguero, Carolina

    2013-04-01

    with R²= 95. Total metal contents in soils were analyzed by EDXRF (Energy Dispersion X Ray Fluorescence). We obtained RRL (Regional Reference Level), from La Bienvenida soil samples with values 20 Ni; 53 Cr; 38 Cu; 125 Zn; 128 Pb; 26 As, all in mg kg¯¹. Taking into account the values obtained in S.Quintin Pb 10127; Zn 2861; As 183; Cd 138; Cu 331; Ni 60 and Hg 893 mg kg¯¹, we can say that S.Quintin is a highly contaminated area; Bombita and Romanilla we would consider polluted areas where only Ni, As have values below RRL. We found differences in uptake patterns on the three areas due to heterogeneity in soil parameters and acid drainage, especially in S.Quintín mine where only measured uptake of Sb by plant has a good linear correlation with metal content extract with Ammonium Acetate. Romanilla has more homogeneous soil condition where we found an high soil-plant correlation Ag, As, Cd, Zn using EDTA and Acetate. Bombita has a similar characteristics, with high correlations between plants contents and soil in Cd, Cu, Pb, Zn with EDTA and Acetate. Total contents of heavy metal in a soil is not enough to evaluate the Toxicity Potential, it is necessary to know the bioavailable fraction present in the soil and the extractable fraction which proved to be the decisive factor in the content of heavy metal in plant of studied areas; the correlation in metals content soil-plant is higher in extractable content metals than in total content.

  14. Heavy metals in vegetables and respective soils irrigated by canal, municipal waste and tube well waters.

    PubMed

    Ismail, Amir; Riaz, Muhammad; Akhtar, Saeed; Ismail, Tariq; Amir, Mamoona; Zafar-ul-Hye, Muhammad

    2014-01-01

    Heavy metal contamination in the food chain is of serious concern due to the potential risks involved. The results of this study revealed the presence of maximum concentration of heavy metals in the canal followed by sewerage and tube well water. Similarly, the vegetables and respective soils irrigated with canal water were found to have higher heavy metal contamination followed by sewerage- and tube-well-watered samples. However, the heavy metal content of vegetables under study was below the limits as set by FAO/WHO, except for lead in canal-water-irrigated spinach (0.59 mg kg(-1)), radish pods (0.44 mg kg(-1)) and bitter gourd (0.33 mg kg(-1)). Estimated daily intakes of heavy metals by the consumption of selected vegetables were found to be well below the maximum limits. However, a complete estimation of daily intake requires the inclusion of other dietary and non-dietary exposure sources of heavy metals.

  15. Growth and survival of Halimione portulacoides stem cuttings in heavy metal contaminated soils.

    PubMed

    Andrades-Moreno, L; Cambrollé, J; Figueroa, M E; Mateos-Naranjo, E

    2013-10-15

    The halophytic shrub Halimione portulacoides demonstrates a high tolerance to heavy metal contamination and a capacity for accumulating metals within its tissues. On the Iberian Peninsula, this species has colonized habitats with high levels of metal pollution. The aim of this study is to analyze the response of H. portulacoides stem cuttings to this pollution. Growth, photosynthesis and metal uptake were examined in H. portulacoides through an experiment in which stem cuttings were replanted in metal-contaminated soil. This condition decreased growth and lowered both photosynthetic rate and stomatal conductance. Reduced photosynthetic performance was largely due to the reduced concentration of photosynthetic pigments. Despite these responses, there was some important evidence suggesting the phytoremediatory potential of Halimione stem cuttings. The results of our study indicate that this salt-marsh shrub may represent a biotool of value in the restoration of polluted areas. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Response of rhizosphere microbial community structure and diversity to heavy metal co-pollution in arable soil.

    PubMed

    Deng, Linjing; Zeng, Guangming; Fan, Changzheng; Lu, Lunhui; Chen, Xunfeng; Chen, Ming; Wu, Haipeng; He, Xiaoxiao; He, Yan

    2015-10-01

    Due to the emerging environmental issues related to heavy metals, concern about the soil quality of farming lands near manufacturing district is increasing. Investigating the function of soil microorganisms exposed to long-term heavy metal contamination is meaningful and important for agricultural soil utilization. This article studied the potential influence of several heavy metals on microbial biomass, activity, abundance, and community composition in arable soil near industrial estate in Zhuzhou, Hunan province, China. The results showed that soil organic contents (SOC) were significantly positive correlated with heavy metals, whereas dehydrogenase activity (DHA) was greatly depressed by the heavy metal stress. Negative correlation was found between heavy metals and basal soil respiration (BSR), and no correlation was found between heavy metals and microbial biomass content (MBC). The quantitative PCR (QPCR) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis could suggest that heavy metal pollution has significantly decreased abundance of bacteria and fungi and also changed their community structure. The results could contribute to evaluate heavy metal pollution level in soil. By combining different environmental parameters, it would promote the better understanding of heavy metal effect on the size, structure, and activity of microbial community in arable soil.

  17. Earthworms (Eisenia fetida) demonstrate potential for use in soil bioremediation by increasing the degradation rates of heavy crude oil hydrocarbons.

    PubMed

    Martinkosky, Luke; Barkley, Jaimie; Sabadell, Gabriel; Gough, Heidi; Davidson, Seana

    2017-02-15

    Crude oil contamination widely impacts soil as a result of release during oil and gas exploration and production activities. The success of bioremediation methods to meet remediation goals often depends on the composition of the crude oil, the soil, and microbial community. Earthworms may enhance bioremediation by mixing and aerating the soil, and exposing soil microorganisms to conditions in the earthworm gut that lead to increased activity. In this study, the common composting earthworm Eisenia fetida was tested for utility to improve remediation of oil-impacted soil. E. fetida survival in soil contaminated with two distinct crude oils was tested in an artificial (lab-mixed) sandy loam soil, and survival compared to that in the clean soil. Crude oil with a high fraction of light-weight hydrocarbons was more toxic to earthworms than the crude oil with a high proportion of heavy polyaromatic and aliphatic hydrocarbons. The heavier crude oil was added to soil to create a 30,000mg/kg crude oil impacted soil, and degradation in the presence of added earthworms and feed, feed alone, or no additions was monitored over time and compared. Earthworm feed was spread on top to test effectiveness of no mixing. TPH degradation rate for the earthworm treatments was ~90mg/day slowing by 200days to ~20mg/day, producing two phases of degradation. With feed alone, the rate was ~40mg/day, with signs of slowing after 500days. Both treatments reached the same end point concentrations, and exhibited faster degradation of aliphatic hydrocarbons C21, decreased. During these experiments, soils were moderately toxic during the first three months, then earthworms survived well, were active and reproduced with petroleum hydrocarbons present. This study demonstrated that earthworms accelerate bioremediation of crude oil in soils, including the degradation of the heaviest polyaromatic fractions.

  18. Modeling the Impact of Soil Conditions on Global Water Balance

    NASA Astrophysics Data System (ADS)

    Wang, P. L.; Feddema, J. J.

    2016-12-01

    The amount of water the soil can hold for plant use, defined as soil water-holding capacity (WHC), has a large influence on the water cycle and climatic variables. Although soil properties vary widely worldwide, many climate modeling applications assume WHC to be spatially invariant. This study explores how a more realistic soil WHC estimate affects the global water balance relative to commonly assumed soil properties. We use a modified Thornthwaite water balance model combined with a newly developed soil WHC and soil thickness data at a 30 arc second resolution. The soil WHC data was obtained by integrating WHCs to a depth of 2 m and modified by the soil thickness data on a grid-by-grid basis, and then resampling to the 0.5 degree climatology data. We observed that down scaling soils data before modifying soil depths greatly increases global soil WHCs. This new dataset is compared to WHC information with a fixed 2-m soil depth, and a constant 150-mm soil WHC. Results indicate higher soil WHC results in increased soil moisture, decreased moisture surplus and deficits, and increased actual evapotranspiration (AE), and vice-versa. However, due to high variability in soil characteristics across climate gradients, this generalization does not hold true for regionally averaged outcomes. Compared to using a constant 150-mm WHC, more realistic soil WHC increases global averaged AE 1%, and decreases deficit 2% and surplus 3%. Most change is observed in areas with pronounced wet and dry seasons; using a constant 2-m soil depth doubles the differences. Regionally, Europe was most affected: AE increases 4%, and the deficit and surplus decrease 20% and 12%. Australia shows that regionally averaged results are not equivocal for moisture surplus and deficit; deficit decreases 0.4%, while surplus decreases 9%. This research highlights the importance of soil condition for climate modeling and how a better representation of soil moisture conditions affects global water balance

  19. A review of soil heavy metal pollution from mines in China: pollution and health risk assessment.

    PubMed

    Li, Zhiyuan; Ma, Zongwei; van der Kuijp, Tsering Jan; Yuan, Zengwei; Huang, Lei

    2014-01-15

    Heavy metal pollution has pervaded many parts of the world, especially developing countries such as China. This review summarizes available data in the literature (2005-2012) on heavy metal polluted soils originating from mining areas in China. Based on these obtained data, this paper then evaluates the soil pollution levels of these collected mines and quantifies the risks these pollutants pose to human health. To assess these potential threat levels, the geoaccumulation index was applied, along with the US Environmental Protection Agency (USEPA) recommended method for health risk assessment. The results demonstrate not only the severity of heavy metal pollution from the examined mines, but also the high carcinogenic and non-carcinogenic risks that soil heavy metal pollution poses to the public, especially to children and those living in the vicinity of heavily polluted mining areas. In order to provide key management targets for relevant government agencies, based on the results of the pollution and health risk assessments, Cd, Pb, Cu, Zn, Hg, As, and Ni are selected as the priority control heavy metals; tungsten, manganese, lead-zinc, and antimony mines are selected as the priority control mine categories; and southern provinces and Liaoning province are selected as the priority control provinces. This review, therefore, provides a comprehensive assessment of soil heavy metal pollution derived from mines in China, while identifying policy recommendations for pollution mitigation and environmental management of these mines.

  20. Phytoremediation strategies for soils contaminated with heavy metals: Modifications and future perspectives.

    PubMed

    Sarwar, Nadeem; Imran, Muhammad; Shaheen, Muhammad Rashid; Ishaque, Wajid; Kamran, Muhammad Asif; Matloob, Amar; Rehim, Abdur; Hussain, Saddam

    2017-03-01

    Presence of heavy metals in agricultural soils is of major environmental concern and a great threat to life on the earth. A number of human health risks are associated with heavy metals regarding their entry into food chain. Various physical, chemical and biological techniques are being used to remove heavy metals and metalloids from soils. Among them, phytoremediation is a good strategy to harvest heavy metals from soils and have been proven as an effective and economical technique. In present review, we discussed various sources and harmful effects of some important heavy metals and metalloids, traditional phytoremediation strategies, mechanisms involved in phytoremediation of these metals, limitations and some recent advances in phytoremediation approaches. Since traditional phytoremediation approach poses some limitations regarding their applications at large scale, so there is a dire need to modify this strategy using modern chemical, biological and genetic engineering tools. In view of above, the present manuscript brings both traditional and advanced phytoremediation techniques together in order to compare, understand and apply these strategies effectively to exclude heavy metals from soil keeping in view the economics and effectiveness of phytoremediation strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Common plants as alternative analytical tools to monitor heavy metals in soil

    PubMed Central

    2012-01-01

    Background Herbaceous plants are common vegetal species generally exposed, for a limited period of time, to bioavailable environmental pollutants. Heavy metals contamination is the most common form of environmental pollution. Herbaceous plants have never been used as natural bioindicators of environmental pollution, in particular to monitor the amount of heavy metals in soil. In this study, we aimed at assessing the usefulness of using three herbaceous plants (Plantago major L., Taraxacum officinale L. and Urtica dioica L.) and one leguminous (Trifolium pratense L.) as alternative indicators to evaluate soil pollution by heavy metals. Results We employed Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) to assess the concentration of selected heavy metals (Cu, Zn, Mn, Pb, Cr and Pd) in soil and plants and we employed statistical analyses to describe the linear correlation between the accumulation of some heavy metals and selected vegetal species. We found that the leaves of Taraxacum officinale L. and Trifolium pratense L. can accumulate Cu in a linearly dependent manner with Urtica dioica L. representing the vegetal species accumulating the highest fraction of Pb. Conclusions In this study we demonstrated that common plants can be used as an alternative analytical tool for monitoring selected heavy metals in soil. PMID:22594441

  2. Benefits of the Use of Sewage Sludge over EDTA to Remediate Soils Polluted with Heavy Metals.

    PubMed

    Hernández, Ana J; Gutiérrez-Ginés, María J; Pastor, Jesús

    2015-09-01

    Sewage sludges from urban wastewater treatment plants are often used to remediate degraded soils. However, the benefits of their use in metal-polluted soils remain unclear and need to be assessed in terms of factors besides soil fertility. This study examines the use of thermal-dried sewage sludge (TDS) as an amendment for heavy metal-polluted soil in terms of its effects on soil chemical properties, leachate composition, and the growth of native plant communities. To assess the response of the soil and its plant community to an increase in metal mobilization, the effects of TDS amendment were compared with those of the addition of a chelating agent (ethylenediaminetetraacetic acid [EDTA]). The experimental design was based on a real-case scenario in which soils from of an abandoned mine site were used in a greenhouse bioassay. Two doses of TDS and EDTA were applied to a soil containing high Pb, Zn, Cu, and Cd levels (4925, 5675, 404, and 25 mg kg, respectively). Soil pH was 6.4, and its organic matter content was 5.53%. The factors examined after soil amendment were soil fertility and heavy metal contents, leachate element losses, the plant community arising from the seed bank (plant cover, species richness and biodiversity, above/below ground biomass), and phytotoxic effects (chemical contents of abundant species). Thermal-dried sewage sludge emerged as a good phytostabilizer of Pb, Zn, Cu, and Cd given its capacity to reduce the plant uptake of metals and achieve rapid plant cover. This amendment also enhanced the retention of other elements in the plant root system and overall showed a better capacity to remediate soils polluted with several heavy metals. The addition of EDTA led to plant productivity losses and nutritional imbalances because it increased the mobility of several elements in the soil and its leachates.

  3. Effects of mycorrhizae and other soil microbes on revegetation of heavy metal contaminated mine spoil.

    PubMed

    Shetty, K G; Hetrick, B A; Figge, D A; Schwab, A P

    1994-01-01

    The effects of mycorrhizal fungi and other soil microorganisms on growth of two grasses, Andropogon gerardii Vitm. and Festuca arundinacea Schreb., in heavy metal-contaminated soil and mine tailings were investigated. A. gerardii is highly dependent on mycorrhizal fungi in native prairie, while F. arundinacea is a facultative mycotroph and relies on mycorrhizal symbiosis only in extremely infertile soils. Regardless of microbial amendments, neither plant species was able to establish and grow in the mine tailings. Both plant species grew in the moderately contaminated or non-contaminated soils, although A. gerardii grew in these soils only when mycorrhizal. Other soil microbes significantly improved growth of A. gerardii only in uncontaminated soil, but to a lesser extent than mycorrhizae. Although F. arundinacea was more highly colonized by mycorrhizal fungi than A. gerardii, neither microbial amendment affected growth of fescue in any soil. In several treatments mycorrhizal fungi adapted to uncontaminated soil stimulated plant growth more than mycorrhizae adapted to the moderately contaminated soil. However, mycorrhizal fungi adapted to contaminated soil did not increase the productivity of plant growth in contaminated soil more than fungi adapted to uncontaminated soil. A. gerardii plants inoculated with mycorrhizal fungi retained more Zn in roots than in shoots, confirming earlier reports that mycorrhizal fungi alter the translocation pattern of heavy metals in host plants. In contrast, mycorrhizae did not affect translocation patterns in F. arundinaceae, suggesting that the mycorrhizal dependence of a plant species is correlated with the retention of metals in roots. The correlation between mycorrhizal dependence of a plant species and mycorrhizal alteration of translocation pattern may also explain the inconsistent reports of mycorrhizal effects on translocation of heavy metals in plants. Plant response to mycorrhizal symbiosis may therefore provide a useful

  4. Ecological risk assessment of heavy metals in soils surrounding oil waste disposal areas.

    PubMed

    Xu, Jianling; Wang, Hanxi; Liu, Yuanyuan; Ma, Mengchao; Zhang, Tian; Zheng, Xiaoxue; Zong, Meihan

    2016-02-01

    More attention is being devoted to heavy metal pollution because heavy metals can concentrate in higher animals through the food chain, harm human health and threaten the stability of the ecological environment. In this study, the effects of heavy metals (Cu, Cr, Zn, Pb, Cd, Ni and Hg) emanating from oil waste disposal on surrounding soil in Jilin Province, China, were investigated. A potential ecological risk index was used to evaluate the damage of heavy metals and concluded that the degree of potential ecological damage of heavy metals can be ranked as follows: Hg > Cd > Pb > Cu > Ni > Cr > Zn. The average value of the potential ecological harm index (Ri) is 71.93, thereby indicating light pollution. In addition, this study researched the spatial distribution of soil heavy metals by means of ArcGIS (geographic information system) spatial analysis software. The results showed that the potential ecological risk index (R) of the large value was close to the distance from the oil waste disposal area; it is relatively between the degree of heavy metals in soil and the distance from the waste disposal area.

  5. Heavy metals in urban ambient PM10 and soil background in eight cities around China.

    PubMed

    Wang, Qiong; Bi, Xiao-Hui; Wu, Jian-Hui; Zhang, Yu-Fen; Feng, Yin-Chang

    2013-02-01

    The ambient PM(10) and background soil samples were collected and analyzed with ICP-AES in eight cities around China to investigate the levels of ten heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The mean concentrations of ten heavy metals in PM(10) of the eight cities of China followed the order of Zn > Pb > Mn > Cu > Ni > Cr > Co > V. The metals in the ambient PM(10) and soil were compared in each city to evaluate the heavy metal mass fraction from anthropogenic sources in ambient air. The CD values in these cities were all above 0.2, indicating that the ingredients spectrums of PM(10) and soil vary markedly. Most heavy metals were enriched in PM(10), except Fe and Ti. The results showed that almost all the cities suffer important heavy metal pollution from anthropogenic sources. The eight cities were also grouped according to their similarity in heavy metals of ambient PM(10) by cluster analysis to investigate the relationship between the heavy metals and the pollution sources of each city. The conclusion was that the eight cities were divided into three clusters which had similar industrial type and economy scale: the first cluster consisted of Shenzhen, Wuxi, and Guiyang; followed by Jinan and Zhengzhou as the second grouping; and the third group had Taiyuan, Urumqi, and Luoyang.

  6. Date palm waste biochars alter a soil respiration, microbial biomass carbon, and heavy metal mobility in contaminated mined soil.

    PubMed

    Al-Wabel, Mohammad I; Usman, Adel Rabie A; Al-Farraj, Abdullah S; Ok, Yong Sik; Abduljabbar, Adel; Al-Faraj, Abdulelah I; Sallam, Abdelazeem S

    2017-04-19

    A 30-day incubation experiment was conducted using a heavy metal-contaminated mined soil amended with date palm feedstock (FS) and its derivative biochars (BCs) at three pyrolysis temperatures of 300 (BC-300), 500 (BC-500), and 700 °C (BC-700) with different application rates (0.0, 5, 15, and 30 g kg(-1)) to investigate their short-term effects on soil respiration (CO2-C efflux), microbial biomass carbon (MBC), soil organic carbon (SOC), mobile fraction of heavy metals (Cd, Cu, Pb, Zn, Mn, and Fe), pH, and electrical conductivity (EC). The results showed that FS and BC-300 with increasing addition rate significantly reduced soil pH, whereas SOC, CO2-C efflux, and soil MBC were increased compared to the control. On the contrary, BC-500 and BC-700 increased soil pH at early stage of incubation and have small or no effects on SOC, CO2-C efflux, and MBC. Based on the results, the date palm biochars exhibited much lower cumulative CO2-C efflux than feedstock, even with low-temperature biochar, indicating that BCs have C sequestration potential. Applying BC-700 at 15 and 30 g kg(-1) significantly reduced cumulative CO2-C efflux by 21.8 and 45.4% compared to the control, respectively. The incorporation of FS into contaminated soil significantly increased the mobile content of Cd and Mn, but decreased the mobile content of Cu. However, BC-300 significantly reduced the mobile content of Cd, Cu, Pb, and Zn. It could be concluded that low-temperature biochar could be used as a soil amendment for reducing heavy metal mobility in mining contaminated soil in addition to minimize soil CO2-C efflux.

  7. Risk assessment of heavy metal contaminated soil in the vicinity of a lead/zinc mine.

    PubMed

    Li, Jing; Xie, Zheng-miao; Zhu, Yong-guan; Naidu, Ravi

    2005-01-01

    Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemical species and availability of lead, zinc, cadmium and copper in nine surface (0 to 20 cm) soils from near an abandoned lead/zinc mine tailings located in Shaoxing, Zhejiang, China. Total heavy metal contents ranged from 5271 to 16369 mg/kg for Pb, 387 to 1221 mg/kg for Zn, 3.0 to 9.3 mg/kg for Cd and 65 to 206 mg/kg for Cu. In general, all heavy metals exceeded China National Standards for Soil Environmental Quality of Heavy Metals by a factor of 3-65 times. Comparison of the heavy metal concentrations (Pb, Zn, Cd and Cu) with clay content revealed a strongly significant relationship while significant relationship (P < 0.001) was also obtained between Cd + Zn and Pb + Cu. Solid phase speciation of the soils using Tessier procedure showed that the heavy metals were distributed in the order: residual > organically complexed-Fe-Mn oxides occluded > carbonate bound > exchangeable > water soluble. In the organic matter fraction, the ratio of Pb (29.1%) to its total concentration in the soils was higher than those of Zn (4.70%), Cd (3.16%) and Cu (9.50%). The percentages of the water soluble and the exchangeable fractions of Pb (1.80%) and Cd (2.74%) were markedly greater than those of Zn (0.10%) and Cu (0.15%), suggesting that Pb and Cd are relatively more mobile and hence more toxic in the contaminated soils. Strongly significant relationships between H2O-Pb, H2O-Zn and H2O-Cu, strong positive correlations between H2O-Pb, H2O-Zn, H2O-Cu and organic matter in soil were found. The content of H2O-Pb, H2O-Zn, H2O-Cu was negatively correlated with pH values. The similar negative relationships between pH values and exchangeable heavy metals were also recorded. It is suggested that increasing soil pH or liming the soil could decrease bioavailability of heavy

  8. Nutrients, heavy metals and phthalate acid esters in solar greenhouse soils in Round-Bohai Bay-Region, China: impacts of cultivation year and biogeography.

    PubMed

    Chen, Zhiqun; Tian, Tian; Gao, Lihong; Tian, Yongqiang

    2016-07-01

    Solar greenhouse is a common facility type used for horticultural crop production in China. However, most solar greenhouse fields have been degraded due to continuous cropping and excessive fertilizer use. Therefore, we investigated solar greenhouse soils covering a wide range of cultivation years and environmental conditions in Round-Bohai Bay-Region to test the effects of cultivation year and biogeography on nutrients, heavy metals, and phthalate acid esters (PAEs). In general, soil pH decreased while soil electrical conductivity (EC), organic matter (OM), total nitrogen (TN), NO3 (-)-N, NH4 (+)-N, mineral nitrogen (MN), Olsen-P, and NH4OAc-K contents increased as time of cultivation increased. However, this trend was influenced by sampling sites. Among sampling sites, Jiangsu showed a relatively low soil pH and high Olsen-P content, while Hebei showed a relatively high soil EC value, NO3 (-)-N, NH4 (+)-N, MN, and NH4OAc-K contents. Liaoning was characterized by relatively high soil OM and TN contents. The nutrient level indexes in evaluation of soil quality on Olsen-P and NH4OAc-K exceeded the standard seriously. The maximum values of the heavy metals Cd, Cu, and Zn were 4.87, 2.78, and 1.15 times higher than the threshold values, respectively. There was a rising trend on the heavy metal contents with the increasing cultivation years, and this trend was significantly influenced by sampling sites. Both Cu and Zn had relative high heavy metal indexes in evaluation of soil pollution. The PAEs were not detected in almost all sampling soils. Overall, the excessive fertilizer application was an important cause of nutrient accumulation and heavy metal pollution, resulting in soil degradation in solar greenhouses.

  9. Pedogenesis, geochemical forms of heavy metals, and artifact weathering in an urban soil chronosequence, Detroit, Michigan.

    PubMed

    Howard, Jeffrey L; Olszewska, Dorota

    2011-03-01

    An urban soil chronosequence in downtown Detroit, MI was studied to determine the effects of time on pedogenesis and heavy metal sequestration. The soils developed in fill derived from mixed sandy and clayey diamicton parent materials on a level late Pleistocene lakebed plain under grass vegetation in a humid-temperate (mesic) climate. The chronosequence is comprised of soils in vacant lots (12 and 44 years old) and parks (96 and 120 years old), all located within 100 m of a roadway. An A-horizon 16 cm thick with 2% organic matter has developed after only 12 years of pedogenesis. The 12 year-old soil shows accelerated weathering of iron (e.g. nails) and cement artifacts attributed to corrosion by excess soluble salts of uncertain origin. Carbonate and Fe-oxide are immobilizing agents for heavy metals, hence it is recommended that drywall, plaster, cement and iron artifacts be left in soils at brownfield sites for their ameliorating effects.

  10. Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater, Akaki, Ethiopia

    NASA Astrophysics Data System (ADS)

    Fitamo, Daniel; Itana, Fisseha; Olsson, Mats

    2007-02-01

    The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0-20 and 30-50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0-20 cm; and Cr, Ni, Cu, Cd, and Zn at 30-50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction

  11. [Soil heavy metals concentration in different type plantations in Harbin City].

    PubMed

    Sun, Hui-zhen; Lu, Xiao-jing; Chen, Ming-yue; Cai, Chun-ju; Zhu, Ning

    2011-03-01

    In order to understand the soil heavy metals characteristics in different type plantations in Harbin City, 0-10 cm and 10-30 cm soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Pinus koraiensis + P. amurense + B. platyphylla) established in the Urban Forestry Demonstration Research Base of Northeast Forestry University in the 1950s to analyze the concentrations of Cu, Zn, Cd, Ni, Pb, and As, and the comprehensive pollution index was used to assess the soil heavy metals pollution in the plantations, based on the background values of black soil in the City. There existed significant differences in the heavy metals concentration in the same soil layers among different type plantations. In the test plantations, the concentrations of soil heavy metals except As and Ni tended to decrease with soil depth. In the same soil layers, Zn had the highest concentration (62.29-126.35 mg x kg(-1)), while Cd had the lowest one (0.06-0.47 mg x kg(-1)). The abundance and accumulation tendency of test heavy metals in the plantations was in the order of Zn>Pb>Cu(Ni)> Ni(Cu)>As>Cd, and Cd>Pb>Zn>Cu>Ni>As, respectively. There existed positive correlations among soil Cu, Zn, Pb, and Cd concentrations in the plantations except F. mandshurica, and the concentrations of these four heavy metals in the plantations except F. mandshurica and Q. mongolica were positively correlated with soil organic matter, N, P, and K. The concentrations of soil Cd, Pb, Zn, and Cu were higher than the background values, suggesting the anthropogenic inputs; while those of Ni and As were similar to or lower than the background values, suggesting the origin from soil materials. The soil comprehensive pollution index of the plantations

  12. Concentration and transportation of heavy metals in vegetables and risk assessment of human exposure to bioaccessible heavy metals in soil near a waste-incinerator site, South China.

    PubMed

    Li, Ning; Kang, Yuan; Pan, Weijian; Zeng, Lixuan; Zhang, Qiuyun; Luo, Jiwen

    2015-07-15

    There is limited study focusing on the bioaccumulation of heavy metals in vegetables and human exposure to bioaccessible heavy metals in soil. In the present study, heavy metal concentrations (Cr, Ni, Cu, Pb and Cd) were measured in five types of vegetables, soil, root, and settled air particle samples from two sites (at a domestic waste incinerator and at 20km away from the incinerator) in Guangzhou, South China. Heavy metal concentrations in soil were greater than those in aerial parts of vegetables and roots, which indicated that vegetables bioaccumulated low amount of heavy metals from soil. The similar pattern of heavy metal (Cr, Cd) was found in the settled air particle samples and aerial parts of vegetables from two sites, which may suggest that foliar uptake may be an important pathway of heavy metal from the environment to vegetables. The highest levels of heavy metals were found in leaf lettuce (125.52μg/g, dry weight) and bitter lettuce (71.2μg/g) for sites A and B, respectively, followed by bitter lettuce and leaf lettuce for sites A and B, respectively. Swamp morning glory accumulated the lowest amount of heavy metals (81.02μg/g for site A and 53.2μg/g for site B) at both sites. The bioaccessibility of heavy metals in soil ranged from Cr (2%) to Cu (71.78%). Risk assessment showed that Cd and Pb in soil samples resulted in the highest non-cancer risk and Cd would result in unacceptable cancer risk for children and risk. The non-dietary intake of soil was the most important exposure pathway, when the bioaccessibility of heavy metals was taken into account. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Impact of Soil Heavy Metal Pollution on Food Safety in China.

    PubMed

    Zhang, Xiuying; Zhong, Taiyang; Liu, Lei; Ouyang, Xiaoying

    2015-01-01

    Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had the lowest pollution rates at lower than 1%. The total pollution rate in Chinese farmland soil was 10.18%, mainly from Cd, Hg, Cu, and Ni. The human activities of mining and smelting, industry, irrigation by sewage, urban development, and fertilizer application released certain amounts of heavy metals into soil, which resulted in the farmland soil being polluted. Considering the spatial variations of grain production, about 13.86% of grain production was affected due to the heavy metal pollution in farmland soil. These results many provide valuable information for agricultural soil management and protection in China.

  14. A feasibility study on bioelectrokinetics for the removal of heavy metals from tailing soil.

    PubMed

    Lee, Keun-Young; Kim, Hyun-A; Lee, Byung-Tae; Kim, Soon-Oh; Kwon, Young-Ho; Kim, Kyoung-Woong

    2011-01-01

    The combination of bioremediation and electrokinetics, termed bioelectrokinetics, has been studied constantly to enhance the removal of organic and inorganic contaminants from soil. The use of the bioleaching process originating from Fe- and/or S-oxidizing bacteria may be a feasible technology for the remediation of heavy metal-contaminated soils. In this study, the bioleaching process driven by injection of S-oxidizing bacteria, Acidithiobacillus thiooxidans, was evaluated as a pre-treatment step. The bioleaching process was sequentially integrated with the electrokinetic soil process, and the final removal efficiency of the combined process was compared with those of individual processes. Tailing soil, heavily contaminated with Cd, Cu, Pb, Zn, Co, and As, was collected from an abandoned mine area in Korea. The results of geochemical studies supported that this tailing soil contains the reduced forms of sulfur that can be an energy source for A. thiooxidans. From the result of the combined process, we could conclude that the bioleaching process might be a good pre-treatment step to mobilize heavy metals in tailing soil. Additionally, the electrokinetic process can be an effective technology for the removal of heavy metals from tailing soil. For the sake of generalizing the proposed bioelectrokinetic process, however, the site-specific differences in soil should be taken into account in future studies.

  15. Impact of Soil Heavy Metal Pollution on Food Safety in China

    PubMed Central

    Zhang, Xiuying; Zhong, Taiyang; Liu, Lei; Ouyang, Xiaoying

    2015-01-01

    Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had the lowest pollution rates at lower than 1%. The total pollution rate in Chinese farmland soil was 10.18%, mainly from Cd, Hg, Cu, and Ni. The human activities of mining and smelting, industry, irrigation by sewage, urban development, and fertilizer application released certain amounts of heavy metals into soil, which resulted in the farmland soil being polluted. Considering the spatial variations of grain production, about 13.86% of grain production was affected due to the heavy metal pollution in farmland soil. These results many provide valuable information for agricultural soil management and protection in China. PMID:26252956

  16. Spatial distribution of heavy metals in the surface soil of source-control stormwater infiltration devices - Inter-site comparison.

    PubMed

    Tedoldi, Damien; Chebbo, Ghassan; Pierlot, Daniel; Branchu, Philippe; Kovacs, Yves; Gromaire, Marie-Christine

    2017-02-01

    Stormwater runoff infiltration brings about some concerns regarding its potential impact on both soil and groundwater quality; besides, the fate of contaminants in source-control devices somewhat suffers from a lack of documentation. The present study was dedicated to assessing the spatial distribution of three heavy metals (copper, lead, zinc) in the surface soil of ten small-scale infiltration facilities, along with several physical parameters (soil moisture, volatile matter, variable thickness of the upper horizon). High-resolution samplings and in-situ measurements were undertaken, followed by X-ray fluorescence analyses and spatial interpolation. Highest metal accumulation was found in a relatively narrow area near the water inflow zone, from which concentrations markedly decreased with increasing distance. Maximum enrichment ratios amounted to >20 in the most contaminated sites. Heavy metal patterns give a time-integrated vision of the non-uniform infiltration fluxes, sedimentation processes and surface flow pathways within the devices. This element indicates that the lateral extent of contamination is mainly controlled by hydraulics. The evidenced spatial structure of soil concentrations restricts the area where remediation measures would be necessary in these systems, and suggests possible optimization of their hydraulic functioning towards an easier maintenance. Heterogeneous upper boundary conditions should be taken into account when studying the fate of micropollutants in infiltration facilities with either mathematical modeling or soil coring field surveys.

  17. Indicators: Soil Chemistry

    EPA Pesticide Factsheets

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  18. Biotic contexts alter metal sequestration and AMF effects on plant growth in soils polluted with heavy metals.

    PubMed

    Glassman, Sydney I; Casper, Brenda B

    2012-07-01

    Investigating how arbuscular mycorrhizal fungi (AMF)-plant interactions vary with edaphic conditions provides an opportunity to test the context-dependency of interspecific interactions. The relationship between AMF and their host plants in the context of other soil microbes was studied along a gradient of heavy metal contamination originating at the site of zinc smelters that operated for a century. The site is currently under restoration. Native C3 grasses have reestablished, and C4 grasses native to the region but not the site were introduced. Interactions involving the native mycorrhizal fungi, non-mycorrhizal soil microbes, soil, one C3 grass (Deschampsia flexuosa), and one C4 grass (Sorghastrum nutans) were investigated using soils from the two extremes of the contamination gradient in a full factorial greenhouse experiment. After 12 weeks, plant biomass and root colonization by AMF and non-mycorrhizal microbes were measured. Plants from both species grew much larger in soil from low-contaminated (LC) origin than high-contaminated (HC) origin. For S. nutans, the addition of a non-AMF soil microbial wash of either origin increased the efficacy of AMF from LC soils but decreased the efficacy of AMF from HC soils in promoting plant growth. Furthermore, there was high mortality of S. nutans in HC soil, where plants with AMF from HC died sooner. For D. flexuosa, plant biomass did not vary with AMF source or the microbial wash treatment or their interaction. While AMF origin did not affect root colonization of D. flexuosa by AMF, the presence and origin of AMF did affect the number of non-mycorrhizal (NMF) morphotypes and NMF root colonization. Adding non-AMF soil biota reduced Zn concentrations in shoots of D. flexuosa. Thus the non-AMF biotic context affected heavy metal sequestration and associated NMF in D. flexuosa, and it interacted with AMF to affect plant biomass in S. nutans. Our results should be useful for improving our basic ecological understanding of

  19. Leaching of heavy metals (Cu, Ni and Zn) and organic matter after sewage sludge application to Mediterranean forest soils.

    PubMed

    Toribio, Montse; Romanyà, Joan

    2006-06-15

    In Mediterranean dry and semiarid areas, soil organic matter is often depleted due to ancient and intensive human activity. Under these conditions the use of sewage sludge as a land reclamation technique may be a means to revert desertification processes and to enhance soil function and nutrient cycling. However, applications of heavy metal-contaminated sewage sludges can significantly increase potentially toxic metal concentrations in soils and metal transfer to freshwater and plants. The aims of this study are 1) to investigate the leaching of Cu, Zn and Ni from three contrasted Mediterranean forest soils (a basic loam, a basic clay, and an acid loam) treated with sewage sludges and 2) to explore the relationships between metal mobility and soil properties and with the leaching of organic matter. The selected soils were incubated in columns (5 replicatesx3 soilsx3 treatments). Treatments were (a) soil application of low metal content sewage sludge (LMS), (b) soil application of metal-enriched sewage sludge (MES), and (c) control. The sewage sludge application represented a dose of 6 kg dry weight m-2. Soil columns were incubated at room temperature for 110 days and were irrigated weekly with deionised water to make a total of a 1130 mm. Leachates were collected and analysed for pH, EC, organic carbon Cu, Ni and Zn concentrations. The concentration of metals and organic matter in the leachates depended on the soil characteristics and on the type of sewage sludge added to the soil. Basic soils with a high amount of clay showed the highest metal retention capacity, while acid soils with low clay content showed the lowest. Of the three metals studied, Ni exhibited the greatest mobility. Zn mobility was also rather high, particularly in the acid soil. Despite the fact that basic soils showed greater OM content than the acid soil, organic carbon in leachates after sludge addition was of the same order of magnitude in all studied soils. OM mobility may enhance the

  20. Sequential extraction evaluation of heavy-metal-contaminated soil: How clean is clean?

    SciTech Connect

    Li, Wen; Peters, R.W.; Brewster, M.D.; Miller, G.A.

    1995-07-01

    As a result of industrial and military operations, large amounts of land have become contaminated with heavy metals. A growing public awareness of metal toxicity in soils and water has forced increased treatment and improved remediation techniques. To develop an adequate knowledge base to definitively judge the usefulness of the remediation technology requires some basic research in how the contaminants are bound in the soil. In this study, the classic five-step sequential extractions were performed on heavy-metal-contaminated soil from Aberdeen Proving Ground to determine the speciation of the metal forms. This technique speciates the heavy metal distribution into an easily extractable (exchangeable) form, carbonates, reducible oxides, organically-bound forms, and residual forms. In order to compare the results of these fractionations with the amount of heavy metals extracted by chelating agents, multi-stage extractions with EDTA were also performed. The results were used to determine the feasibility of using soil washing and soil flushing techniques for remediating the Aberdeen metals-contaminated soils.

  1. Effects of Heavy, Tracked-Vehicle Disturbance on Forest Soil Properties at Fort Benning, Georgia

    SciTech Connect

    Garten, C.T.,JR.

    2004-05-20

    The purpose of this report is to describe the effects of heavy, tracked-vehicle disturbance on various measures of soil quality in training compartment K-11 at Fort Benning, Georgia. Predisturbance soil sampling in April and October of 2002 indicated statistically significant differences in soil properties between upland and riparian sites. Soil density was less at riparian sites, but riparian soils had significantly greater C and N concentrations and stocks than upland soils. Most of the C stock in riparian soils was associated with mineral-associated organic matter (i.e., the silt + clay fraction physically separated from whole mineral soil). Topographic differences in soil N availability were highly dependent on the time of sampling. Riparian soils had higher concentrations of extractable inorganic N than upland soils and also exhibited significantly greater soil N availability during the spring sampling. The disturbance experiment was performed in May 2003 by driving a D7 bulldozer through the mixed pine/hardwood forest. Post-disturbance sampling was limited to upland sites because training with heavy, tracked vehicles at Fort Benning is generally confined to upland soils. Soil sampling approximately one month after the experiment indicated that effects of the bulldozer were limited primarily to the forest floor (O-horizon) and the surface (0-10 cm) mineral soil. O-horizon dry mass and C stocks were significantly reduced, relative to undisturbed sites, and there was an indication of reduced mineral soil C stocks in the disturbance zone. Differences in the surface (0-10 cm) mineral soil also indicated a significant increase in soil density as a result of disturbance by the bulldozer. Although there was some tendency for greater soil N availability in disturbed soils, the changes were not significantly different from undisturbed controls. It is expected that repeated soil disturbance over time, which will normally occur in a military training area, would simply

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

    PubMed

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

    2010-01-15

    While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of "calcite or carbonate" (CaCO(3)) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

  3. Effect of soil and cover conditions on soil-water relationships

    Treesearch

    George R., Jr. Trimble; Charles E. Hale; H. Spencer Potter

    1951-01-01

    People who make flood-control surveys for the U.S. Department of Agriculture are concerned with the physical condition of the soils in the watersheds. The condition of the soil determines how fast water moves into and through the soil, and how much water is held in storage. The condition of the soil has a great influence on stream flow, erosion, floods and water supply...

  4. Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

    PubMed Central

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

    2014-01-01

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

  5. Residual impact of aged nZVI on heavy metal-polluted soils.

    PubMed

    Fajardo, C; Gil-Díaz, M; Costa, G; Alonso, J; Guerrero, A M; Nande, M; Lobo, M C; Martín, M

    2015-12-01

    In the present study, the residual toxicity and impact of aged nZVI after a leaching experiment on heavy metal (Pb, Zn) polluted soils was evaluated. No negative effects on physico-chemical soil properties were observed after aged nZVI exposure. The application of nZVI to soil produced a significant increase in Fe availability. The impact on soil biodiversity was assessed by fluorescence in situ hybridization (FISH). A significant effect of nZVI application on microbial structure has been recorded in the Pb-polluted soil nZVI-treated. Soil bacteria molecular response, evaluated by RT-qPCR using exposure biomarkers (pykA, katB) showed a decrease in the cellular activity (pykA) due to enhanced intracellular oxidative stress (katB). Moreover, ecotoxicological standardised test on Caenorhabditis elegans (C. elegans) showed a decrease in the growth endpoint in the Pb-polluted soil, and particularly in the nZVI-treated. A different pattern has been observed in Zn-polluted soils: no changes in soil biodiversity, an increase in biological activity and a significant decrease of Zn toxicity on C. elegans growth were observed after aged nZVI exposure. The results reported indicated that the pollutant and its nZVI interaction should be considered to design soil nanoremediation strategies to immobilise heavy metals.

  6. Metabolic and bacterial diversity in soils historically contaminated by heavy metals and hydrocarbons.

    PubMed

    Vivas, Astrid; Moreno, Beatriz; del Val, Coral; Macci, Cristina; Masciandaro, Grazia; Benitez, Emilio

    2008-11-01

    The aim of this study was to characterize soils contaminated by different levels of heavy metals and hydrocarbons (Madonna Dell'Acqua, Pisa, Italy). The soils were chemically and biochemically analysed by measuring the standard chemical properties and some enzyme activities related to microbial activity (dehydrogenase activity) and the soil carbon cycle (total and extracellular beta-glucosidase activities). The metabolic capacities of soil microorganisms to degrade hydrocarbons through catechol 2,3-dioxygenase were also described. The microbial diversity of contaminated and uncontaminated soils was estimated by denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA sequences. The PCR/single-strand conformation polymorphism (PCR/SSCP) method was used to estimate the genetic diversity of PAH-degrading genes in both contaminated and uncontaminated soils. A greater bacterial diversity and lower catechol 2,3-dioxygenase activity was detected in unpolluted soils. The complexity of the microbial community (Shannon and Simpson indices) as well as the dehydrogenase soil activity negatively correlated with contamination levels. The greatest PAH-degrading gene diversity and the most intense catechol 2,3-dioxygenase activity were found in the soils with the highest levels of hydrocarbons. Heavy metals and hydrocarbon pollution has caused a genetic and metabolic alteration in microbial communities, corresponding to a reduction in microbial activity. A multi-technique approach combining traditional biochemical methods with molecular-based techniques, along with some methodological improvements, may represent an important tool to expand our knowledge of the role of microbial diversity in contaminated soil.

  7. [Effects of applying sewage sludge on chemical form distribution and bioavailability of heavy metals in soil].

    PubMed

    Song, Lin-Lin; Tie, Mei; Zhang, Zhao-Hong; Hui, Xiu-Juan; Jing, Kui; Chen, Zhong-Lin; Zhang, Ying

    2012-10-01

    A pot experiment was conducted to study the effects of applying sewage sludge on the chemical form distribution of heavy metals (Cd, Pb, Cu and Zn) in soil and the transfer and accumulation of the heavy metals in soil-plant (ryegrass) system. With the application of sewage sludge, the contents of bioavailable Cd and Zn in soil increased significantly but that of bioavailable Pb in soil had a significant decrease, and the content of residual form Pb in soil increased by 33.3% -74.5%, compared with CK. When the application rate of sewage sludge was 50% (M/M) of soil, the contents of exchangeable and reducible Cu in soil only occupied 0.7% and 0.2% of the total Cu respectively. The application of sewage sludge promoted the Cd, Cu and Zn absorption while inhibited the Pb absorption by ryegrass. Multiple linear regression analysis showed that the Cd, Zn and Cu contents in ryegrass were positively correlated with the reducible Cd and Zn and oxidizable Cu contents in soil, respectively, and Pb content in ryegrass was highly correlated with the soil exchangeable and oxidizable Pb contents. After planting ryegrass, the oxidizable Cd and Cu in rhizosphere soil were transformed into exchangeable Cd and residual form Cu, respectively, the exchangeable and reducible Zn transformed into oxidizable Zn, whereas the bioavailability of Pb was less affected.

  8. Geospatial Distribution of Heavy Metals in an Urban Soil, El Paso, Texas, USA

    NASA Astrophysics Data System (ADS)

    Amaya, M. A.; Elkekli, A. R.; Clague, J. W.; Grimida, S. E.; Pingitore, N. E., Jr.

    2014-12-01

    Some 500 city blocks were selected randomly via population-based stratification. Equal volumes of soil collected from the public space (where present) in front of each house on a block yielded a composite sample. Composites provide neighborhood level "smoothing" relative to sampling many individual houses, and greatly decrease laboratory effort/cost. In the laboratory 10 g of soil were comminuted in a ceramic ball mill, mixed with cellulose/ paraffin binder, and pressed (20 tons) into a pellet. A Panalytical Epsilon5 EDS-XRF, using 8 sequential secondary target conditions and 12 NIST and USGS multi-element rock standards provided analyses. The concentration of Pb ranged from 11 to 420 ppm; Cr, 4.3 - 52 ppm; Cu, 6.5 - 390 ppm; Zn, 17 - 480 ppm; Cd, 0.4 - 12 ppm; and Sb, 2.9 - 20 ppm. High levels of all metals characterize the urban core area of El Paso, which dates to the late 19th Century. This area hosts both commercial and old residential structures, as well as major highways and a large railroad yard. There currently is, and was in the past, considerable light industry in the area. Two highly traveled highway and one railroad border crossing over the Rio Grande into contiguous Cd. Juarez (population close to 2 million) add to current and past contamination. A century-old Pb-Cu-Zn smelter, recently demolished, forms the western boundary of the urban core. Heavy metal pollution from the smelter is recognized near the former site. Its effect on the rest of the urban core is uncertain due to the current and former presence of other heavy metal sources. Aggressive post-World War II growth and expansion of El Paso into the surrounding desert, as is common in the US Southwest, placed newer housing onto more pristine land surfaces. This is reflected in generally low-to-background levels of heavy metals in these newer areas of the city. Thus there is a strong contamination and heavy metals exposure risk gradient between older and newer neighborhoods within a single city

  9. Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants

    PubMed Central

    Al-Wabel, Mohammad I.; Usman, Adel R.A.; El-Naggar, Ahmed H.; Aly, Anwar A.; Ibrahim, Hesham M.; Elmaghraby, Salem; Al-Omran, Abdulrasoul

    2014-01-01

    The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5–102% at 75% FC and 133–266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity. PMID:26150758

  10. Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants.

    PubMed

    Al-Wabel, Mohammad I; Usman, Adel R A; El-Naggar, Ahmed H; Aly, Anwar A; Ibrahim, Hesham M; Elmaghraby, Salem; Al-Omran, Abdulrasoul

    2015-07-01

    The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5-102% at 75% FC and 133-266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity.

  11. [Distribution Characteristics and Potential Ecological Hazards Assessment of Soil Heavy Metals in Typical Soil Profiles in Southeast Suburb of Beijing].

    PubMed

    Zhao, Qian; Ma, Lin; Liu, Yi-fei; He, Jiang-tao; Li, Guang-he

    2016-05-15

    To investigate the distribution characteristics and the potential ecology risk of different types of heavy metals, soil samples were collected from various stratigraphic sections in the southeastern suburb of Beijing, where soil heavy metal (Cu, Pb, Cr, As) contents were measured and analyzed using multivariate statistical analysis and the potential ecological risk index method. The results showed that the concentrations of the four heavy metals followed the order of Cr > Cu > As > Pb with variable coefficients ranging from 59.60% to 159.33% at 3-6 m stratum, which all displayed a high degree of variability. The concentrations of Cu and Pb were positively correlated with soil organic matter (SOM), cation exchange capacity (CEC), etc, with higher eigenvalues in Factor 1 and 2, demonstrating the impact of organic colloid on the occurrence of heavy metals. The risk level of the specific heavy metal followed the order of As > Cu > Pb > Cr, where As already showed a medium potential ecological risk in the studied area.

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

    PubMed

    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.

  13. Soil heavy metal contamination and risk assessment around the Fenhe Reservoir, China.

    PubMed

    Zhang, Hong; Liu, Guanglei; Shi, Wei; Li, Jinchang

    2014-08-01

    Heavy metal contamination in the soil around a water source is a particularly serious issue, because these heavy metals can be transferred into the water source and can pose significant human health risks through the contamination of drinking water or farmland irrigation water. In this paper, we collected surface soil samples from the area surrounding the Fenhe Reservoir. The concentrations of As, Cd, Cr, Cu, Hg, Ni, and Zn were determined and the potential ecological risks posed by the heavy metals were quantitatively evaluated. The primary inputs for As, Ni, and Zn were natural sources, whereas the other elements were derived from mainly anthropogenic sources. Hg displays more serious environmental impacts than the other heavy metals. The upper reaches of the reservoir, located in the northwest, display a higher potential ecological risk.

  14. The Extent and Prediction of Heavy Metal Pollution in Soils of Shahrood and Damghan, Iran.

    PubMed

    Sakizadeh, Mohamad; Mirzaei, Rouhollah; Ghorbani, Hadi

    2015-12-01

    The levels of 12 heavy metals (Ag, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Tl, V, Zn) were considered in 229 soil samples in Semnan Province, Iran. To discriminate between natural and anthropogenic inputs of heavy metals, factor analysis was used. Seven factors accounting for 90.5 % of the total variance were extracted. The mining and agricultural activities along with geogenic sources have been attributed as the main causes of the levels of heavy metals in the study area. The partial least squares regression was utilized to predict the level of soil pollution index (SPI) considering the concentrations of 12 heavy metals. The eigenvectors from the first three PLS represented more than 98 % of the overall variance. The correlation coefficient between the observed and predicted SPI was 0.99 indicating the high efficiency of this method. The resultant coefficient of determination for three PLS components was 0.984 confirming the predictive ability of this method.

  15. Soil contamination by heavy metals in the city: a case study of Petach-Tikva, Israel

    NASA Astrophysics Data System (ADS)

    Sarah, Pariente; Zhevelev, Helena; Ido-Lichtman, Orna

    2017-04-01

    Heavy metals are among the most important pollutants which are affected by human activities. These pollutants impact both the natural and urban ecosystems. In the latter they are associated with the human health of the residents. The general aim of the study is to investigate the spatial variability of soil heavy metals in the city of Petach-Tikva. We asked if and to what extent the urban structure determines the spatial pattern of soil contamination. Urban structure in this study refers to the morphology of neighborhoods (density and height of buildings), the industrial area location and the roads system. It includes three main and industrial areas in the margins of the city. The city is also subjected to heavy traffic and contains different types of neighborhood morphology. To promote the above aim a preliminary study was conducted in 2016. Soil sampling was carried out along a strip, running from the Northwest industrial region of the city to the residential region in the center. Soil samples were randomly taken, from 0-5 cm, from industrial, near high traffic roads and between buildings areas. Each was analyzed for three heavy metals (Pb, Zn, Cu) commonly associated with industry and traffic emissions. Primary results show that for all the city studied areas the range values of Cu Zn and Pb concentrations were 1800, 1270 and 150 ppm, respectively, meaning high spatial variability of the heavy metals. In the soil of the industrial area the averages and the maximum values of Pb, Zn, and Cu concentrations were 76, 353 and 500 ppm and 153, 1286 and 1847 ppm, respectively. In the soil between buildings the averages were 20, 78 and 13 ppm and the maximum values reached 38, 165 and 37 ppm for Pb, Zn, and Cu, respectively. In the soil near roads the averages were 39, 120 and 214 ppm, and the maximum values were 153, 477 and 74 ppm for Pb, Zn, and Cu, respectively. These results indicate that the city industry has the greatest effect on soil pollution. Within the city

  16. Contamination and Spatial Variation of Heavy Metals in the Soil-Rice System in Nanxun County, Southeastern China

    PubMed Central

    Zhao, Keli; Fu, Weijun; Ye, Zhengqian; Zhang, Chaosheng

    2015-01-01

    There is an increasing concern about heavy metal contamination in farmland in China and worldwide. In order to reveal the spatial features of heavy metals in the soil-rice system, soil and rice samples were collected from Nanxun, Southeastern China. Compared with the guideline values, elevated concentrations of heavy metals in soils were observed, while heavy metals in rice still remained at a safe level. Heavy metals in soils and rice had moderate to strong spatial dependence (nugget/sill ratios: 13.2% to 49.9%). The spatial distribution of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in soils illustrated that their high concentrations were located in the southeast part. The high concentrations of cadmium (Cd) in soils were observed in the northeast part. The accumulation of all the studied metals is related to the long-term application of agrochemicals and industrial activities. Heavy metals in rice showed different spatial distribution patterns. Cross-correlograms were produced to quantitatively determine the spatial correlation between soil properties and heavy metals composition in rice. The pH and soil organic matter had significant spatial correlations with the concentration of heavy metals in rice. Most of the selected variables had clear spatial correlation ranges for heavy metals in rice, which could be further applied to divide agricultural management zones. PMID:25635917

  17. Contamination and spatial variation of heavy metals in the soil-rice system in Nanxun County, Southeastern China.

    PubMed

    Zhao, Keli; Fu, Weijun; Ye, Zhengqian; Zhang, Chaosheng

    2015-01-28

    There is an increasing concern about heavy metal contamination in farmland in China and worldwide. In order to reveal the spatial features of heavy metals in the soil-rice system, soil and rice samples were collected from Nanxun, Southeastern China. Compared with the guideline values, elevated concentrations of heavy metals in soils were observed, while heavy metals in rice still remained at a safe level. Heavy metals in soils and rice had moderate to strong spatial dependence (nugget/sill ratios: 13.2% to 49.9%). The spatial distribution of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in soils illustrated that their high concentrations were located in the southeast part. The high concentrations of cadmium (Cd) in soils were observed in the northeast part. The accumulation of all the studied metals is related to the long-term application of agrochemicals and industrial activities. Heavy metals in rice showed different spatial distribution patterns. Cross-correlograms were produced to quantitatively determine the spatial correlation between soil properties and heavy metals composition in rice. The pH and soil organic matter had significant spatial correlations with the concentration of heavy metals in rice. Most of the selected variables had clear spatial correlation ranges for heavy metals in rice, which could be further applied to divide agricultural management zones.

  18. Uptake of certain heavy metals from contaminated soil by mushroom--Galerina vittiformis.

    PubMed

    Damodaran, Dilna; Vidya Shetty, K; Raj Mohan, B

    2014-06-01

    Remediation of soil contaminated with heavy metals has received considerable attention in recent years. In this study, the heavy metal uptake potential of the mushroom, Galerina vittiformis, was studied in soil artificially contaminated with Cu (II), Cd (II), Cr (VI), Pb (II) and Zn (II) at concentrations of 50 and 100mg/kg. G. vittiformis was found to be effective in removing the metals from soil within 30 days. The bioaccumulation factor (BAF) for both mycelia and fruiting bodies with respect to these heavy metals at 50mg/kg concentrations were found to be greater than one, indicating hyper accumulating nature by the mushroom. The metal removal rates by G. vittiformis was analyzed using different kinetic rate constants and found to follow the second order kinetic rate equation except for Cd (II), which followed the first order rate kinetics. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

  20. Heavy metals in soils along unpaved roads in south west Cameroon: Contamination levels and health risks.

    PubMed

    Ngole-Jeme, Veronica M

    2016-04-01

    Soils enriched with heavy metals from vehicular emission present a significant exposure route of heavy metals to individuals using unpaved roads. This study assessed the extent of Cd, Cr, Co, Cu, Ni, Pb and Zn contamination of soils along unpaved roads in Cameroon, and the health risks presented by incidental ingestion and dermal contact with the soils using metal contamination factor (CF) pollution load index, hazard quotients (HQ) and chronic hazard index (CHI). CF values obtained (0.9-12.2) indicate moderate to high contamination levels. HQ values for Cr, Cd and Pb exceeded the reference doses. Moderate health hazard exists for road users in the areas with intense anthropogenic activities and high average daily traffic (ADT) volume according to CHI values (1-4) obtained. The economy and quality of life in cities with unpaved roads could be threatened by health challenges resulting from long-term exposure to heavy metal derived from high ADT volumes.

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

    PubMed

    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.

  2. [Health risk assessment of soil heavy metals in residential communities built on brownfields].

    PubMed

    Chen, Xing; Ma, Jian-Hua; Li, Xin-Ning; Liu, De-Xin; Li, Yi-Meng

    2014-03-01

    Nine residential communities which were built on different brownfields in a city of Henan Province were chosen to investigate the health risks of heavy metals (As, Hg, Cd, and Pb) in surface soils. Concentrations of soil heavy metals were measured according to the methods described in the national standard. Based on the health risk models recommended by the U. S. Environmental Protection Agency (US EPA), non-carcinogenic and carcinogenic health risks of soil heavy metals were assessed. The results showed that compared with the original brownfields, the heavy metal concentrations in soils and their health risks in residential communities built on brownfields were significantly improved, and the concentrations and health risks of soil heavy metals in these communities were all higher than those in non-brownfield residential communities. The HQ and HI values of soil heavy metals in all the residential communities were lower than 1, which indicated that there was no non-carcinogenic risk in these communities. Meanwhile, the values of CR and TCR were slightly higher than the standard suggested by the US EPA, indicating that slight carcinogenic risks in the communities, but these values were lower than the lenient standard proposed by some experts. The HI value of the four metals for children was exactly seven times higher than that for adults. The contribution rate of HQ(As) to HI was about 75%, CR(AS) to TCR was about 80%, and therefore arsenic was the crucial factor for carcinogenic and non-carcinogenic risk in the residential communities of the city.

  3. Germination and Persistence of Rangeland Grasses on Heavy Metal Soils

    USDA-ARS?s Scientific Manuscript database

    Many of acres of Western rangeland have been degraded by mining and other land disturbances which often result in soil with elevated salinity, increased acidity, high levels of sodium, metals, and decreased nutrient availability. Chemical amendment of degraded soils followed by reseeding has result...

  4. Germination and Persistence of Rangeland Grasses on Heavy Metal Soils

    USDA-ARS?s Scientific Manuscript database

    Many acres of Western rangeland have been degraded by mining and other land disturbances which often results in soil with elevated salinity, increased acidity, high levels of sodium, metals, and decreased nutrient availability. Chemical amendment of degraded soils followed by reseeding has resulted...

  5. Release and bioavailability of zinc and heavy metals in fly ash amended soil and mine spoil

    SciTech Connect

    Elmosly, W.A.

    1990-01-01

    Heavy metals concentrations were estimated in an acid Zn deficient soil (Clymer) and a pyritic acid mine spoil (Lenox) treated with three fly ashes at rates of 0, 33, and 66% after incubation at field capacity, saturation, and cycles of wetting, leaching, and drying. Metals were extracted with DTPA, HCl, Mehlich 3, MgCl[sub 2], ammonium acetate, and H[sub 2]O. Incorporation of alkaline fly ashes into both soils significantly increased soil pH. Extractability of all metals depended on pH of the soil-ash mixtures, characteristics of soils and ashes, and nature of the extractant. Moisture only affected extractability of Cr, Fe, and Mn. Zinc levels were increased in the Clymer soil but decreased in the Lenox spoil. Water solubility of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn was determined on three alkaline fly ashes. A greenhouse study with two successive corn crops was conducted to determine yield, plant availability of Zn, and uptake of heavy metals in the plant tops grown on Clymer and Lenox soils treated with three fly ashes at rates of 0, 33, 66%. Fly ash addition usually caused: (a) corn tops yield depression, especially for the second crop, (b) increase in plant Zn concentration on Zn-deficient Clymer soil, (c) decrease in Mn toxicity on Lenox spoil, and (d) increase in Cd, Co, Cr, Cu, Ni, and Pb plants. The high concentrations of these metals in corn tissues may have been due to stunted growth. Quality of the soil environment by heavy fly ash additions has been shown to be improved with respect to plant nutrition of Zn and Mn, but may have deteriorated by increase in heavy metals.

  6. Chelant extraction of heavy metals from contaminated soils using new selective EDTA derivatives.

    PubMed

    Zhang, Tao; Liu, Jun-Min; Huang, Xiong-Fei; Xia, Bing; Su, Cheng-Yong; Luo, Guo-Fan; Xu, Yao-Wei; Wu, Ying-Xin; Mao, Zong-Wan; Qiu, Rong-Liang

    2013-11-15

    Soil washing is one of the few permanent treatment alternatives for removing metal contaminants. Ethylenediaminetetraacetic acid (EDTA) and its salts can substantially increase heavy metal removal from contaminated soils and have been extensively studied for soil washing. However, EDTA has a poor utilization ratio due to its low selectivity resulting from the competition between soil major cations and trace metal ions for chelation. The present study evaluated the potential for soil washing using EDTA and three of its derivatives: CDTA (trans-1,2-cyclohexanediaminetetraacetic acid), BDTA (benzyldiaminetetraacetic acid), and PDTA (phenyldiaminetetraacetic acid), which contain a cylcohexane ring, a benzyl group, and a phenyl group, respectively. Titration results showed that PDTA had the highest stability constants for Cu(2+) and Ni(2+) and the highest overall selectivity for trace metals over major cations. Equilibrium batch experiments were conducted to evaluate the efficacy of the EDTA derivatives at extracting Cu(2+), Zn(2+), Ni(2+), Pb(2+), Ca(2+), and Fe(3+) from a contaminated soil. At pH 7.0, PDTA extracted 1.5 times more Cu(2+) than did EDTA, but only 75% as much Ca(2+). Although CDTA was a strong chelator of heavy metal ions, its overall selectivity was lower and comparable to that of EDTA. BDTA was the least effective extractant because its stability constants with heavy metals were low. PDTA is potentially a practical washing agent for soils contaminated with trace metals. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Decomposer animal communities in forest soil along heavy metal pollution gradient.

    PubMed

    Haimi, J; Siira-Pietikäinen, A

    1996-03-01

    Responses of soil decomposer animals to heavy metal contamination and to concomitant changes in organic matter quality and quantity and in soil microbial biomasses have been studied along a pollution gradient from a Cu-Ni smelter. Samples have been taken separately for nematodes, enchytraeids and microarthropods 0.5, 2 and 8 km from the smelter. Special attention has been paid to the changes in the collembolan fauna. The sampling sites have been located in homogeneous Scots pine ( Pinus sylvestris) forests with podsolic soil profiles. In addition, an experiment has been carried out in which intact soil cores have been transferred in mesh baskets between the sites 2 and 8 km from the smelter (control samples have been transferred within the sites). Although most soil animals seemed to be quite resistant to direct and indirect effects of heavy metals, results indicate that certain soil animals like enchytraeids can be useful and easy to monitor when the effects of heavy metals on soil decomposition systems are assessed.

  8. Bioleaching of heavy metals from a contaminated soil using indigenous Penicillium chrysogenum strain F1.

    PubMed

    Deng, Xinhui; Chai, Liyuan; Yang, Zhihui; Tang, Chongjian; Tong, Haixia; Yuan, Pingfu

    2012-09-30

    Bioleaching of heavy metals from contaminated soil using Penicillium chrysogenum strain F1 was investigated. Batch experiments were performed to compare leaching efficiencies of heavy metals between one-step and two-step processes and to determine the transformation of heavy metal fractions before and after bioleaching. The results showed that two-step process had higher leaching efficiencies of heavy metals than one-step process. When the mass ratio of soil to culture medium containing P. chrysogenum strain F1 was 5% (w/v), 50%, 35%, 9% and 40% of Cd, Cu, Pb and Zn were removed in one-step process, respectively. The two-step process had higher removals of 63% Cd, 56% Cu, 14% Pb and 54% Zn as compared with one-step process. The results of the sequential extraction showed that the metals remaining in the soil were mainly bonded in stable fractions after bioleaching. The results of TEM and SEM showed that during bioleaching process, although the mycelium of P. chrysogenum was broken into fragments, no damage was obviously observed on the surface of the living cell except for thinner cell wall, smaller vacuoles and concentrated cytoplasm. The result implied that P. chrysogenum strain F1 can be used to remove heavy metals from polluted soil.

  9. Paddy soil — A suitable target for monitoring heavy metal pollution by magnetic proxies

    NASA Astrophysics Data System (ADS)

    Yan, H. T.; Hu, S. Y.; Blaha, U.; Rösler, W.; Duan, X. M.; Appel, E.

    2011-10-01

    A preliminary magnetic study around Meishan steel mill in Nanjing (SE China) was carried out combining geochemical analysis with scanning electron microscopy (SEM) to prove that paddy soil can be a suitable target for environmental study on heavy metal pollution. Magnetic background investigation showed a strong variation in this area due to different land uses and soil types. Magnetic susceptibilities (MS) measured on forest soils are much higher than in paddy fields, and values below 20 cm of the soil surface in forest with parent material of Xiashu loess are several times higher than in paddy soil with parent material of fluvisol. Measurements on vertical profiles show that paddy soil has a very low and stable magnetic background with mass-specific MS around 15 × 10 - 8 m 3 kg - 1 . A strong enhancement of MS values is found in the upper ~ 20 cm of paddy soil predominated by multidomain and pseudo single domain magnetite. However, relatively low S-ratios (0.57 to 0.85) reveal a significant contribution of imperfect anti-ferromagnetic minerals. Detailed research on a paddy soil core at site C719 near the steel mill indicates strong correlation between magnetic mineral concentration-related parameters (χ, ARM, SIRM) and heavy metal concentrations of Cu, Pb and Zn. In addition, typical anthropogenic Fe-spherules are detected in top paddy soil by means of SEM, which indicates that the increase of susceptibility in upper soil is mainly caused by steel mill emission. Mapping of MS in paddy fields across the steel mill area shows a decrease of MS with the distance to the major emission zone. Positive correlation between χ and Zn is found by measuring surface soil samples around the steel mill. Because of low background and high homogeneity of the ~ 20 cm uppermost mixing layer paddy fields are especially suitable for magnetic surface mapping of heavy metal pollution.

  10. [Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

    PubMed

    Deng, Hong-xia; Yang, Ya-li; Li, Zhen; Xu, Yan; Li, Rong-hua; Meng, Zhao-fu; Yang, Ya-ti

    2015-04-01

    In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

  11. Review in Strengthening Technology for Phytoremediation of Soil Contaminated by Heavy Metals

    NASA Astrophysics Data System (ADS)

    Wu, Chishan; Zhang, Xingfeng; Deng, Yang

    2017-07-01

    In view of current problems of phytoremediation technology, this paper summarizes research progress for phytoremediation technology of heavy metal contaminated soil. When the efficiency of phytoremediation may not meet the demand in practice of contaminated soil or water. Effective measures should be taken to improve the plant uptake and translocation. This paper focuses on strengthening technology mechanism, which can not only increase the biomass of plant and hyperaccumulators, but also enhance the tolerance and resistance to heavy metals, and application effect of phytoremediation, including agronomic methods, earthworm bioremediation and chemical induction technology. In the end of paper, deficiencies of each methods also be discussed, methods of strengthening technology for phytoremediation need further research.

  12. Effects of heavy metals on the litter consumption by the earthworm Lumbricus rubellus in field soils

    USGS Publications Warehouse

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

    2006-01-01

    Aim of this study was to determine effects of heavy metals on litter consumption by the earthworm Lumbricus rubellus in National Park the "Brabantsche Biesbosch", the Netherlands. Adult L. rubellus were collected from 12 polluted and from one unpolluted field site. Earthworms collected at the unpolluted site were kept in their native soil and in soil from each of the 12 Biesbosch sites. Earthworms collected in the Biesbosch were kept in their native soils. Non-polluted poplar (Populus sp.) litter was offered as a food source and litter consumption and earthworm biomass were determined after 54 days. Cd, Cu and Zn concentrations were determined in soil, pore water and 0.01 M CaCl2 extracts of the soil and in earthworms. In spite of low available metal concentrations in the polluted soils, Cd, Cu and Zn concentrations in L. rubellus were increased. The litter consumption rate per biomass was positively related to internal Cd and Zn concentrations of earthworms collected from the Biesbosch and kept in native soil. A possible explanation is an increased demand for energy, needed for the regulation and detoxification of heavy metals. Litter consumption per biomass of earthworms from the reference site and kept in the polluted Biesbosch soils, was not related to any of the determined soil characteristics and metal concentrations. ?? 2005 Elsevier GmbH. All rights reserved.

  13. Response of microbial activities to heavy metals in a neutral loamy soil treated with biosolid.

    PubMed

    Kao, Po-Hsu; Huang, Cheng-Chieh; Hseu, Zeng-Yei

    2006-06-01

    Application of biosolid on land has been widespread in numerous countries for last several decades. This study performed incubation experiments by mixing a neutral loamy soil and biosolid enriched in Cu, Pb and Zn to explore how heavy metal affects soil mineralization and microbial biomass. The experimental results indicated that large nutrient, microorganism and C sources from biosolid were beneficial to microbial respiration. However, compared to the biosolid alone treatment, the supplemented Cu, Pb and Zn in biosolid reduced the mineralized C by roughly 36%. This phenomenon was probably caused by a portion of the Cu, Pb and Zn being complexed with organic matter to prevent decomposition of organic carbon by microorganisms. Equally, soil treated with biosolid increased the quantity of mineralized N by approximately five-fold and accelerated the rate of N mineralization by about one-fold compared to untreated soil. Notably, addition of heavy metals impaired the mineralization process, particularly when Pb reached about 64%. The reduced N mineralization occurred for similar reasons to the microbial respiration. The addition of biosolid in soil considerably increased the amount of mineralizable N; however, the increase was lower in biosolid-treated soil spiked by heavy metals. The addition of heavy metals in the soil-biosolid mixture clearly reduced the microbial biomasses C (MBC) and N (MBN), indicating that the microbial activities had been disrupted by the heavy metals. The microbial biomass C/N ratio had changed initially from 8 to 13 at the end of incubation period, owing to various groups of microbes expressing different mechanisms of metabolism, indicating that the microbial population had changed from bacteria to fungi, which had higher metal tolerance.

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

    PubMed

    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.

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

    PubMed

    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.

  16. [Concentrations of soil heavy metals and their spatial distribution in the surrounding area of Fenhe Reservoir].

    PubMed

    Li, Jin-Chang; Zhang, Hong; Shi, Wei

    2013-01-01

    Based on the concentrations of heavy metals from 95 topsoil samples, the spatial distribution characteristics and sources of the heavy metals in soil of the surrounding area of Fenhe Reservoir were analyzed with a method combining multivariate statistics and geo-statistics. The results showed that the average concentrations of the Cr, Cu, Ni, Pb, and Zn in soil of study area were 38.45, 19.09, 24.02, 11.98 and 55.01 mg x kg(-1), respectively, and all were lower than the first class standard of the national soil environment and the background values of soil in Shanxi Province. For all heavy metals, there were some samples with concentrations higher than the background values of soil in Shanxi Province, especially for Pb, Cr, and Cu, exceeding by 28%, 14%, and 13%, respectively. The results of correlation analysis and factor analysis showed that the sources of the excess of these heavy metals could be divided into three categories, Cu, Ni and Zn as one class, Cr and Pb as the other two classes. Spatial structure analysis showed the excess of Cu, Ni, and Zn came mainly from daily life and production activities, and the excess of Cr and Pb came mainly from agricultural activities and transportation.

  17. Remediation of heavy metal-contaminated forest soil using recycled organic matter and native woody plants.

    PubMed

    Helmisaari, H-S; Salemaa, M; Derome, J; Kiikkilä, O; Uhlig, C; Nieminen, T M

    2007-01-01

    The main aim of this study was to determine how the application of a mulch cover (a mixture of household biocompost and woodchips) onto heavy metal-polluted forest soil affects (i) long-term survival and growth of planted dwarf shrubs and tree seedlings and (ii) natural revegetation. Native woody plants (Pinus sylvestris, Betula pubescens, Empetrum nigrum, and Arctostaphylos uva-ursi) were planted in mulch pockets on mulch-covered and uncovered plots in summer 1996 in a highly polluted Scots pine stand in southwest Finland. Spreading a mulch layer on the soil surface was essential for the recolonization of natural vegetation and increased dwarf shrub survival, partly through protection against drought. Despite initial mortality, transplant establishment was relatively successful during the following 10 yr. Tree species had higher survival rates, but the dwarf shrubs covered a larger area of the soil surface during the experiment. Especially E. nigrum and P. sylvestris proved to be suitable for revegetating heavy metal-polluted and degraded forests. Natural recolonization of pioneer species (e.g., Epilobium angustifolium, Taraxacum coll., and grasses) and tree seedlings (P. sylvestris, Betula sp., and Salix sp.) was strongly enhanced on the mulched plots, whereas there was no natural vegetation on the untreated plots. These results indicate that a heavy metal-polluted site can be ecologically remediated without having to remove the soil. Household compost and woodchips are low-cost mulching materials that are suitable for restoring heavy metal-polluted soil.

  18. [Analysis of heavy metals distribution characteristics and pollution assessment in agricultural region soils of Huaihe basin].

    PubMed

    Xiao, Xue; Zhao, Nan-Jing; Yuan, Jing; Ma, Ming-Jun; Fang, Li; Wang, Yin; Meng, De-Shuo; Yu, Yang; Tang, Jie; Zhang, Xiao-Ling; Dai, Yuan; Zhang, Yu-Jun; Liu, Jian-Guo; Liu, Wen-Qing

    2014-07-01

    By means of field sampling and laboratory analysis, the content distribution characteristics of Cd, Cr, Cu, Ni, Pb and Zn in agricultural region soils of Huaihe basin in Anhui province were analyzed. Assessment of heavy metal pollutions was conducted using enrichment factor, geoaccumulation index and potential ecological risk index. The results showed that the average mass fraction of Cd and Cu was 0.113 5 and 22.09 mg x kg(-1) respectively in the study area soil, which were above the background values 0.097 and 20.4 mg x kg(-1) in Anhui Province. The average mass fraction of other four heavy metals did not exceed the average values of Anhui Province. The results of the evaluations from geoaccumulation index and ecological risk assessment discovered that Cd is the strongest pollution metal among six heavy metals in the study area soil. For some samples of the study soil, Cd was slight risk for the ecosystem. The ecosystem risks caused by the other five heavy metals were not obviously for the sampling points. The entire study area soils were mid integrated potential ecological risk.

  19. The use of volcanic soil as mineral landfill liner--III. Heavy metals retention capacity.

    PubMed

    Navia, Rodrigo; Fuentes, Bárbara; Diez, María C; Lorber, Karl E

    2005-06-01

    The volcanic soil of Southern Chile was tested for its heavy metal retention capacity. The maximum uptakes for CrO4(2-) (CrVI), Cu(2+), Zn(2+) and Pb(2+) were determined to be 2.74, 5.32, 5.86 and 7.44 mg g(-1), respectively. At a slightly alkaline pH value (7.5), it seems that a precipitation-adsorption process was responsible for the Cu(2+) and Zn(2+) uptake onto volcanic soil. All the determined values are of the same order of magnitude as natural zeolites heavy metals adsorption capacities. In addition, the heavy metals diffusion model through a 1 m volcanic soil mineral liner shows breakthrough times of 21.6, 10.2 and 8.9 years, for Pb(2+), Zn(2+) and Cu(2+), respectively, confirming the trend obtained in the adsorption isotherms. The natural volcanic soil of Southern Chile is an interesting material for possible use as landfill mineral basal sealing. It has an appropriate sealing potential (average Kf value of 5.85 x 10(-9) m s(-1)) and a heavy metals retention capacity comparable with natural zeolites. About two-thirds of the agricultural land in Chile (approximately 0.4 million km2) is derived from volcanic ash, suggesting an important soil volume for future landfill projects, that could be obtained in sufficient quantities from urban building activities.

  20. Impact of overland traffic on heavy metal levels in highway dust and soils of Istanbul, Turkey.

    PubMed

    Guney, Mert; Onay, Turgut T; Copty, Nadim K

    2010-05-01

    The purpose of this study was to investigate the impact of overland traffic on the spatial distribution of heavy metals in urban soils (Istanbul, Turkey). Road dust, surface, and subsurface soil samples were collected from a total of 41 locations along highways with dense traffic and secondary roads with lower traffic and analyzed for lead (Pb), zinc (Zn), and copper (Cu) concentrations. Statistical evaluation of the heavy metal concentrations observed along highways and along the secondary roads showed that the data were bimodally distributed. The maximum observed Pb, Zn, and Cu concentrations were 1,573, 522 and 136 mg/kg, respectively, in surface soils along highways and 99.3, 156, and 38.1 mg/kg along secondary roads. Correlation analysis of the metal concentrations in road dust, surface and 20-cm depth soils suggests the presence of a common pollution source. However, metal concentrations in the deeper soils were substantially lower than those observed at the surface, indicating low mobility of heavy metals, especially for Pb and Zn. A modified kriging approach that honors the bimodality of the data was used to estimate the spatial distribution of the surface concentrations of metals, and to identify hotspots. Results indicate that despite the presence of some industrial zones within the study area, traffic is the main heavy metal pollution source.

  1. Effect of Heavy Metals Pollution on Soil Microbial Diversity and Bermudagrass Genetic Variation

    PubMed Central

    Xie, Yan; Fan, Jibiao; Zhu, Weixi; Amombo, Erick; Lou, Yanhong; Chen, Liang; Fu, Jinmin

    2016-01-01

    Heavy metal pollution is a serious global environmental problem as it adversely affects plant growth and genetic variation. It also alters the composition and activity of soil microbial communities. The objectives of this study were to determine the soil microbial diversity, bermudagrass genetic variation in Cd contaminated or uncontaminated soils from Hunan province of China, and to evaluate Cd-tolerance of bermudagrass at different soils. The Biolog method, hydroponic experiments and simple sequence repeat markers were used to assess the functional diversity of microorganisms, Cd-tolerance and the genetic diversity of bermudagrass, respectively. Four of the sampling sites were heavily contaminated with heavy metals. The total bioactivity, richness, and microbial diversity decreased with increasing concentration of heavy metal. The hydroponic experiment revealed that bermudagrass populations collected from polluted sites have evolved, encompassing the feature of a higher resistance to Cd toxicity. Higher genetic diversity was observed to be more in contaminated populations than in uncontaminated populations. Heavy metal pollution can result in adverse effects on plant growth, soil microbial diversity and activity, and apparently has a stronger impact on the genetic structure. The results of this study provide new insights and a background to produce a genetic description of populations in a species that is suitable for use in phytoremediation practices. PMID:27303431

  2. Effect of Heavy Metals Pollution on Soil Microbial Diversity and Bermudagrass Genetic Variation.

    PubMed

    Xie, Yan; Fan, Jibiao; Zhu, Weixi; Amombo, Erick; Lou, Yanhong; Chen, Liang; Fu, Jinmin

    2016-01-01

    Heavy metal pollution is a serious global environmental problem as it adversely affects plant growth and genetic variation. It also alters the composition and activity of soil microbial communities. The objectives of this study were to determine the soil microbial diversity, bermudagrass genetic variation in Cd contaminated or uncontaminated soils from Hunan province of China, and to evaluate Cd-tolerance of bermudagrass at different soils. The Biolog method, hydroponic experiments and simple sequence repeat markers were used to assess the functional diversity of microorganisms, Cd-tolerance and the genetic diversity of bermudagrass, respectively. Four of the sampling sites were heavily contaminated with heavy metals. The total bioactivity, richness, and microbial diversity decreased with increasing concentration of heavy metal. The hydroponic experiment revealed that bermudagrass populations collected from polluted sites have evolved, encompassing the feature of a higher resistance to Cd toxicity. Higher genetic diversity was observed to be more in contaminated populations than in uncontaminated populations. Heavy metal pollution can result in adverse effects on plant growth, soil microbial diversity and activity, and apparently has a stronger impact on the genetic structure. The results of this study provide new insights and a background to produce a genetic description of populations in a species that is suitable for use in phytoremediation practices.

  3. Qualitative evaluation of heavy metals in soils using portable XRF instruments

    SciTech Connect

    McCain, R.G.

    1993-10-01

    Portable isotope-source energy dispersive x-ray fluorescence (XRF) analyzers can provide rapid on site screening for heavy metals in soils. Their use generally involves empirical calibration to a suite of representative soil samples spiked with a range of concentrations of the analytes of interest. In most cases, only a limited number of analytes can be measured with this approach, because of constraints imposed by the operational software and costs associated with preparing the calibration suite. A simple approach is described that provides a qualitative indication of anomalous concentrations of heavy metals based on numeric comparison of gross count rates to background values. This approach can rapidly identify contaminated soils and does not depend on a suite of calibration samples. Direct measurements can be made to rapidly map soil contamination without sample collection, and the method can also be applied to other surfaces such as concrete.

  4. Microbially supported phytoremediation of heavy metal contaminated soils: strategies and applications.

    PubMed

    Phieler, René; Voit, Annekatrin; Kothe, Erika

    2014-01-01

    Heavy metal contamination of soil as a result of, for example, mining operations, evokes worldwide concern. The use of selected metal-accumulating plants to clean up heavy metal contaminated sites represents a sustainable and inexpensive method for remediation approaches and, at the same time, avoids destruction of soil function. Within this scenario, phytoremediation is the use of plants (directly or indirectly) to reduce the risks of contaminants in soil to the environment and human health. Microbially assisted bioremediation strategies, such as phytoextraction or phytostabilization, may increase the beneficial aspects and can be viewed as potentially useful methods for application in remediation of low and heterogeneously contaminated soil. The plant-microbe interactions in phytoremediation strategies include mutually beneficial symbiotic associations such as mycorrhiza, plant growth promoting bacteria (PGPB), or endophytic bacteria that are discussed with respect to their impact on phytoremediation approaches.

  5. Detection of genotoxic effects of heavy metal contaminated soils with plant bioassays.

    PubMed

    Knasmüller, S; Gottmann, E; Steinkellner, H; Fomin, A; Pickl, C; Paschke, A; Göd, R; Kundi, M

    1998-12-03

    Aim of the present study was the development of a bioassay which enables the detection of genotoxic effects of heavy metal contaminated soils. In the first part of the present study, the data base on metal effects in plant bioassays was extended. Four metal salts, namely Cr(VI)O3, Cr(III)Cl3, Ni(II)Cl2 and Sb(III)Cl3 were tested comparatively in MN tests with pollen tetrad cells of Tradescantia clone #4430 and in meristematic root tip cells of Vicia faba. With Cr6+ and Ni2+, clear-cut dose-effects were observed in a range between 0.75 and 10.0 mM, whereas this was not the case with Cr3+ (range tested 1.25-10 mM) and Sb3+ (range 0.30-5.25 mM). In Vicia, negative results were obtained with the four metal salts under all conditions of test. To compare the mutagenic potencies of the metals, the increases of the regression curves (k-values) were calculated, they indicate the number of MN induced per mM in 100 tetrad cells. The corresponding values for Cr6+ and Ni2+ are 0.87 and 1.05, respectively. It appears that the Tradescantia system is in particular sensitive towards those metal species which cause DNA damage in animals and man such as Cr6+, Cd2+, Ni2+, and Zn2+, whereas no clear positive results were obtained with less harmful metal ions such as Cu2+, Cr3+ or Sb3+. In the second part of the study, the mutagenic effects of four metal contaminated soils and two types of standardized leachates (pH 4.0 and pH 7.0) of these soils were tested in Tradescantia and in Vicia. In addition, chemical analyses were carried out to determine the metal concentrations in the soils and in the extracts. Two of the samples contained highly elevated levels of a number of metals (Zn, Pb, Cu, Cd, Sb, As), one soil came from the Central Austrian Alps and contained high As levels only. Direct exposure of the Tradescantia plants in the soils resulted in a drastic increase of the MN frequencies over the background. The lowest effect was seen with the Slovakian soil which contained in

  6. Effect of fly ash application on soil microbial response and heavy metal accumulation in soil and rice plant.

    PubMed

    Nayak, A K; Raja, R; Rao, K S; Shukla, A K; Mohanty, Sangita; Shahid, Mohammad; Tripathi, R; Panda, B B; Bhattacharyya, P; Kumar, Anjani; Lal, B; Sethi, S K; Puri, C; Nayak, D; Swain, C K

    2015-04-01

    Fly ash (FA), a byproduct of coal combustion in thermal power plants, has been considered as a problematic solid waste and its safe disposal is a cause of concern. Several studies proposed that FA can be used as a soil additive; however its effect on microbial response, soil enzymatic activities and heavy metal accumulation in soil and grain of rice (cv. Naveen) to fly ash (FA) application was studied in a pot experiment during dry season 2011 in an Inceptisol. Fly ash was applied at a rate of zero per cent (FS), five per cent (FA5), ten per cent (FA10), twenty per cent (FA20), 40 per cent (FA40) and 100 per cent (FA100) on soil volume basis with nitrogen (N), phosphorus (P) and potassium (K) (40:20:20mg N:P:Kkg(-1) soil) with six replications. Heavy metals contents in soil and plant parts were analysed after harvest of crop. On the other hand, microbial population and soil enzymatic activities were analysed at panicle initiation stage (PI, 65 days after transplanting) of rice. There was no significant change in the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), cadmium (Cd) and chromium (Cr) with application of fly ash up to FA10. However, at FA100 there was significant increase of all metals concentration in soil than other treatments. Microorganisms differed in their response to the rate of FA application. Population of both fungi and actinomycetes decreased with the application of fly ash, while aerobic heterotrophic bacterial population did not change significantly up to FA40. On the other hand, total microbial activity measured in terms of Fluorescein diacetate (FDA) assay, and denitrifiers showed an increased trend up to FA40. However, activities of both alkaline and acid phosphatase were decreased with the application of FA. Application of FA at lower levels (ten to twenty per cent on soil volume basis) in soil enhanced micronutrients content, microbial activities and crop yield.

  7. Effect of heavy metal-solubilizing microorganisms on zinc and cadmium extractions from heavy metal contaminated soil with Tricholoma lobynsis.

    PubMed

    Ji, Ling-yun; Zhang, Wei-wei; Yu, Dong; Cao, Yan-ru; Xu, Heng

    2012-01-01

    The macrofungus, Tricholoma lobynsis, was chosen to remedy Zn-Cd-Pb contaminated soil. To enhance its metal-extracting efficiency, two heavy metal resistant microbes M6 and K1 were applied owing to their excellent abilities to solubilize heavy metal salts. The two isolated microbial strains could also produce indole acetic acid (IAA), siderophore and solubilize inorganic phosphate, but neither of them showed 1-aminocyclopropane-1-carboxylate deaminase activity. The strains M6 and K1 were identified as Serratia marcescens and Rhodotorula mucilaginosa based on 16S rDNA and ITS sequence analysis respectively. Pot experiment showed that spraying to T. lobynsis-inoculated soil with M6 and K1 respectively could increase total Cd accumulations of this mushroom by 216 and 61%, and Zn by 153 and 49% compared to the uninoculated control. Pb accumulation however, was too low (<1 mg kg(-1)) to be determined. The results illustrated that special microbes and macrofungi can work together to remedy polluted soil as plant and plant growth promoting microbes do, probably because of excellent metal-accumulating abilities of macrofungi and IAA-siderophore production, phosphate solubilization abilities of the assisted-microbes. This kind of macrofungi-microbe interaction can be developed into a novel bioremediation strategy.

  8. Facilitated Immobilization of Heavy Metals in Soil by Manipulation with Plant Byproducts

    DTIC Science & Technology

    2005-01-01

    al (8). These responses were compared with pyro-GCMS analyses of purified components such as microcrystalline cellulose (Sigma), indulin AT, and...M. Fan and Richard M. Higashi Acronyms HS – humic substances; AFRPA - Air Force Real Property Agency; Cel – cellulose ; LS – lignosulfonate...to heavy metal ion leaching by conducting soil ageing experiments with McClellan AFRPA soils. Different organic bulk materials including cellulose

  9. Multivariate analysis combined with GIS to source identification of heavy metals in soils around an abandoned industrial area, Eastern China.

    PubMed

    Zhou, Jie; Feng, Ke; Pei, Zongping; Meng, Fang; Sun, Jian

    2016-03-01

    Heavy metals in soils polluted by industrial production are a meaningful topic worldwide. The purpose of this study is to understand the pollution status and spatial distribution of heavy metals in soils. The result can help decision-makers apportion possible soil heavy metals sources and formulate effective pollution control policies. In this paper, 155 soil samples (0-20 cm) were collected and analyzed for eight heavy metals (Cd, Hg, As, Cu, Pb, Cr, Zn, and Ni) from an abandoned industrial area of Tong County, located in Jiangsu Province of Eastern China. The multivariate analysis (including I(geo), Ei/RI, EF, PCA, and CA) and geostatistics (GIS) were used to assess the enrichment level and pollution level of soil heavy metals and identify their sources. The results indicated that eight heavy metals in soils had moderate variations, with CVs ranging from 19.63 to 63.34%. The pollution level of I(geo) of soil heavy metals decreased in the order of Cd~Zn > Cu > Hg~As~Pb~Cr~Ni. The enrichment level of soil heavy metals decreased in the order of Cd > Zn > Hg > Cu > Pb > Ni > As > Cr. According to the Ei, except Cd and Hg were in the significant and moderate ecological risk levels respectively, other soil heavy metals were in the clean or light ecological risk levels, the level of potential ecological risk (RI) of the whole industrial area was moderate. Finally, the source identification of soil heavy metals indicated that Cd and Zn were primarily controlled by human activities, and Hg and Cu were controlled by natural and anthropogenic sources, and As, Pb, Cr, and Ni were mainly controlled by soil parent materials.

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

    PubMed Central

    Greve, Klaus; Atiemo, Sampson M.

    2016-01-01

    Objectives This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. Methods A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (Cdeg), we analyzed the individual contribution of each heavy metal contamination and the overall Cdeg. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. Results Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall Cdeg. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. Conclusions Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and Cdeg, indicating soil contamination in AEPS with the nine heavy metals studied. PMID:26987962

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

    PubMed

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

    2016-01-01

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

  12. Chemical fraction, leachability, and bioaccessibility of heavy metals in contaminated soils, Northeast China.

    PubMed

    Yutong, Zong; Qing, Xiao; Shenggao, Lu

    2016-12-01

    Heavy metals in urban soils may pose risks to both urban environment and human health. However, only a fraction of heavy metals in soil is mobile and/or bioavailable for plant uptake and human ingestion. This study evaluates the chemical fraction and potential mobility and bioaccessibility of heavy metals (Cd, Cr, Cu, Pb, and Zn) in the contaminated urban topsoils from steel-industrial city (Anshan), Northeastern China. Chemical forms of heavy metals in soils are determined using Tessier sequential extraction technique. The toxicity characteristic leaching procedure (TCLP), ethylenediaminetetraacetic acid (EDTA), and US Pharmacopeia methodology (USPM) are used to determine the operationally defined potentially mobile and bioaccessible metal fractions, respectively. Sequential extraction results show that Cd has the highest percentage of exchangeable form, whereas Cr primarily exists in residual form. The non-residual fraction of heavy metals increases in the order of Cr < Cu < Pb < Zn < Cd. The leachability of heavy metals evaluated by TCLP test indicates that Cd, Zn, Cu, and Pb have much higher mobile than Cr. The bioavailability of heavy metals determined by EDTA extraction decreases in the order of Pb > Cu ≅ Zn > Cd > Cr. The order of bioaccessibility determined by USPM extraction is Pb = Cu > Zn > Cd > Cr. The Cr exhibits the lowest leachability and bioaccessibility among the investigated metals. The Pb has the highest bioaccessibility, indicating higher potential hazard for the human health. There are significant relationships between the EDTA- and USPM-extractable metals (Cd, Cu, Pb, and Zn) and the sum of first three steps of sequential extraction. Highly significant correlation is found between amounts of EDTA-extractable Cd, Cu, Pb, and Zn and USPM-extractable metals. The result suggests that EDTA extraction can be helpful to estimate the bioaccessibility of heavy metals for human ingestion. Introduction of mobile and human bioaccessible concentrations

  13. Heavy metal uptake and leaching from polluted soil using permeable barrier in DTPA-assisted phytoextraction.

    PubMed

    Zhao, Shulan; Shen, Zhiping; Duo, Lian

    2015-04-01

    Application of sewage sludge (SS) in agriculture is an alternative technique of disposing this waste. But unreasonable application of SS leads to excessive accumulation of heavy metals in soils. A column experiment was conducted to test the availability of heavy metals to Lolium perenne grown in SS-treated soils following diethylene triamine penta acetic acid (DTPA) application at rates of 0, 10 and 20 mmol kg(-1) soil. In order to prevent metal leaching in DTPA-assisted phytoextraction process, a horizontal permeable barrier was placed below the treated soil, and its effectiveness was also assessed. Results showed that DTPA addition significantly increased metal uptake by L. perenne shoots and metal leaching. Permeable barriers increased metal concentrations in plant shoots and effectively decreased metal leaching from the treated soil. Heavy metals in SS-treated soils could be gradually removed by harvesting L. perenne many times in 1 year and adding low dosage of DTPA days before each harvest.

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

    PubMed

    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.

  15. Phytoavailability of heavy metals in tidal flat soils after fresh water leaching.

    PubMed

    Li, QuSheng; Chen, XiaoJiao; Luo, Xuan; Cui, ZhiHong; Shi, Lei; Wang, LiLi; Liu, YaNan

    2012-05-01

    The phytoavailability of Cd, Pb, Cr, Zn, Cu, and Ni, retained in tidal flat soil after fresh water leaching during reclamation was investigated. Two salt-tolerant varieties of tomato (Lycopersicon esculentum) and edible amaranth (Amaranthus mangostanus L.) were planted in soils having eight different desalination levels (from 6.7 to 1.4 g kg(-1) salinity) using pot experiments. Soil leaching significantly decreased the uptake of all metals by crop roots except for Ni. The reduction of soil salinity and exchangeable fraction content of Cd and Pb after leaching contributed to the decrease of uptake of metals by roots. All heavy metal concentrations in the edible parts of both crops in the two lowest salinity level treatments were lower than their maximum allowable levels in food. Results suggest that reclamation of tidal flats can reduce the phytoavailability of the heavy metals retained in soil. But the soil heavy metals may still pose health risks in the cultivation of root food crops. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Potential use of lateritic and marine clay soils as landfill liners to retain heavy metals.

    PubMed

    Chalermyanont, Tanit; Arrykul, Surapon; Charoenthaisong, Nanthanit

    2009-01-01

    The potential of a lateritic soil and a marine clay, typical of those found in hot and humid climatic regions, was assessed for use as a landfill liner material. A series of tests were conducted - physical and chemical, batch adsorption, column, hydraulic conductivity, etc., - to evaluate the heavy metal sorption capacity, chemical compatibility of hydraulic conductivity, and transport parameters of the soils. Experimental results showed that the marine clay had better adsorption capacity than that of the lateritic soil and that its hydraulic conductivity was an order of magnitude lower. In addition, the hydraulic conductivities of both soils when permeated with low concentration heavy metal solutions were below 1x10(-7)cm/s. When permeated with Cr, Pb, Cd, Zn, and Ni solutions, the retardation factors of the lateritic soil and the marine clay ranged from 10 to 98 and 37 to 165, respectively, while the diffusion coefficients ranged from 1.0x10(-5) to 7.5x10(-6) and 3.0 to 9.14x10(-7)cm2/s, respectively. For both soils, Cr and Pb were retained relatively well, while Cd, Zn, and Ni were more mobile. The marine clay had higher retardation factors and lower diffusion coefficients, and its hydraulic conductivity was more compatible with Cr solution, than that of the lateritic soil. In general, the properties of the marine clay indicate that it has significant advantages over the lateritic soil as landfill liner material.

  17. Analysis of Spatial Variations and Sources of Heavy Metals in Farmland Soils of Beijing Suburbs

    PubMed Central

    Zou, Jianmei; Dai, Wei; Gong, Shengxuan; Ma, Zeyu

    2015-01-01

    To understand the effect of intense human activities in suburbs on environmental quality, we obtained 758 measurements of the heavy metals in certain farmland soils of the Beijing suburbs. Multivariate statistical analysis and geostatistical analysis were used to conduct a basic analysis of the heavy metal concentrations, the distribution characteristics and the sources of pollution of the farmland soils in these suburbs. The results showed the presence of eight heavy metals in the agricultural soils at levels exceeding the background values for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. In particular, all the measured Cr concentrations exceeded the background value, while As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were present at 1.13, 1.68, 1.95, 1.43, 1.63, 0.79, 0.92 and 1.36 times their background values, respectively. The results of correlation, factor and spatial structure analyses showed that Cd, Cu, Pb and Zn were strongly homologous, whereas Cr and Hg showed a degree of heterogeneity. The analysis further indicated that in addition to natural factors, Cd, Cu, Pb and Zn in the soil were mainly associated with distribution from road traffic and land use status. Different agricultural production measures in the various areas were also important factors that affected the spatial distribution of the soil Cr concentration. The major sources of Hg pollution were landfills for industrial waste and urban domestic garbage, while the spatial distribution of As was more likely to be a result of composite pollution. The regional distribution of the heavy metals indicated that except for Cr and Hg, the high heavy metal levels occurred in districts and counties with higher organic matter concentrations, such as the northwestern and southeastern suburbs of Beijing. There was no significant Ni pollution in the agricultural soils of the Beijing suburbs. PMID:25658749

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

    NASA Astrophysics Data System (ADS)

    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

  19. Concentrations of heavy metals in soil, Zimapan, México

    NASA Astrophysics Data System (ADS)

    Ongley, L. K.; Armienta, A.; Mango, H.

    2003-05-01

    Pb-Zn-Ag mining and ore pocessing have occurred continuously in Zimapán, México since at least 1632 and possibly since 1576 [1, 2]. This has resulted in the development of significant slag and tailings piles. Dissolution of ore and tailings has resulted in arsenic contamination of much of the water in the valley raising the possibility of arsenicosis of the residents [3, 4, 5]. INAA and ICP analysis of more than 175 sediment, soil and tailings samples demonstrate significant metal and arsenic contamination of these unconsolidated materials. As, Cu, Pb, and Zn were among the measured elements. Metal concentrations in soils and sediments were highest within 1000 m of tailings or slag piles. Some of the highest soil metal concentrations were measured in a developing soil on top of a slag pile: As-14 700 mg/kg, Cu 8 638 mg/kg, Pb 41444 mg/kg, and Zn 16 976 mg/kg. Soils more than 4 000 m from the tailings and slag generally had less than 40 mg As/kg with Cu < 30 mg/kg, Pb < 64 mg/kg, and Zn < 200 mg/kg. Some rocks ftum the area also show elevated metal concentrations. For example, the As concentrations in dikes and ores from Zimapàn averaged 1 242 and 30 800 mg/kg respectively. Average shale As concentrations (74 mg/kg) match published data for shales that indicate “normal” As concentrations range from 3-490 mg/kg are found world-wide [6]. Some of the soil contamination is natural, the result of the geologic processes responsible for the Pb-Zn ores. However, particularly near the tailings and slag piles, the soils are also contaminated by anthropogenic means: by dry particulate deposition from smelters, by windblown tailings, and possibly by ore and rock dust from the ore transport trucks.

  20. Pyrolytic Treatment and Fertility Enhancement of Soils Contaminated with Heavy Hydrocarbons.

    PubMed

    Vidonish, Julia E; Zygourakis, Kyriacos; Masiello, Caroline A; Gao, Xiaodong; Mathieu, Jacques; Alvarez, Pedro J J

    2016-03-01

    Pyrolysis of contaminated soils at 420 °C converted recalcitrant heavy hydrocarbons into "char" (a carbonaceous material similar to petroleum coke) and enhanced soil fertility. Pyrolytic treatment reduced total petroleum hydrocarbons (TPH) to below regulatory standards (typically <1% by weight) within 3 h using only 40-60% of the energy required for incineration at 600-1200 °C. Formation of polycyclic aromatic hydrocarbons (PAHs) was not observed, with post-pyrolysis levels well below applicable standards. Plant growth studies showed a higher biomass production of Arabidopsis thaliana and Lactuca sativa (Simpson black-seeded lettuce) (80-900% heavier) in pyrolyzed soils than in contaminated or incinerated soils. Elemental analysis showed that pyrolyzed soils contained more carbon than incinerated soils (1.4-3.2% versus 0.3-0.4%). The stark color differences between pyrolyzed and incinerated soils suggest that the carbonaceous material produced via pyrolysis was dispersed in the form of a layer coating the soil particles. Overall, these results suggest that soil pyrolysis could be a viable thermal treatment to quickly remediate soils impacted by weathered oil while improving soil fertility, potentially enhancing revegetation.

  1. Accumulation of heavy metals in a long-term poultry waste-amended soil

    SciTech Connect

    Han, F.X.; Kingery, W.L.; Selim, H.M.; Gerard, P.D.

    2000-03-01

    Various metals are added to poultry diets to facilitate weight increase and disease prevention. The large amounts of poultry waste produced annually are dispersed intensively over relatively small areas of land, resulting in accumulations that pose potential environmental risks to the surface and groundwater. The focus of this study was to assess the distribution of heavy metals among various solid-phase fractions in soil profiles from a 25-year poultry waste-amended soil. Copper and Zn accumulated close to the soil surface where the total amounts of Cu and Zn in waste-amended soils were significantly higher than in nonamended soils. The total metal concentrations in amended soils were not critically high. Copper in the amended soil was present mostly in the organic matter (OM) fraction (46.9%), whereas Zn was found in the easily reducible oxide (ERO) fraction (47.3%). This suggests that the Cu and Zn in this long-term amended soil are potentially bioavailable and mobile. The authors observed the mobility of Zn through much of the soil profile of the long-term waste-amended soil. Zinc in this soil profile was found primarily in forms of the residual (RES) and crystalline iron oxide bound (CryFe) fractions, followed by the organic matter-bound and exchangeable (EXC) fractions.

  2. Deposition of heavy metals from particulate settleable matter in soils of an industrialized area

    NASA Astrophysics Data System (ADS)

    Sanfeliu, Teófilo

    2010-05-01

    Particulate air pollutants from industrial emissions and natural resource exploitation represent an important contribution to soil contamination. These atmospheric particles, usually settleable particulate matter form (which settle by gravity) are deposited on soil through both dry and wet. The most direct consequences on soil of air pollutants are acidification and salinization, not to mention the pollution that can cause heavy metals as components of suspended particulate matter. The main objective of this study was to evaluate the influence of air pollution in soil composition. For this purpose, has been conducted a study of the composition of heavy metals in the settleable particulate matter in two locations (Almazora and Vila-real) with high industrial density (mainly ceramic companies) located in the ceramic cluster of Castellón (Spain). Settleable air particles samples were collected with a PS Standard Britannic captor (MCV-PS2) for monthly periods between January 2007 and December 2009. We analyzed the following elements: Cd, Pb, Cu, Ni, Sb and Bi which are highly toxic and have the property of accumulating in living organisms. It has been determined the concentration of heavy metals in the soluble fraction of settleable air particles by ICP-MS. The annual variation of the results obtained in both populations shows a decline over the study period the concentrations of heavy metals analyzed. This fact is associated with the steady implementation of corrective measures in the main industrial sector in the area based on the treatment of mineral raw materials. Moreover, this decline is, in turn, a lower intake of heavy metals to the soil. REFERENCES Gómez E.T.; Sanfeliu T.; Rius J.; Jordán M.M. (2005) "Evolution, sources and distribution of mineral particles and amorphous phase of atmospheric aerosol in an industrial and Mediterranean coastal area" Water, air and Soil Pollution 167:311-330 Moral R., Gilkes R.J.; Jordán M.M. (2005) "Distribution of heavy

  3. Transformation of heavy metal fractions on soil urease and nitrate reductase activities in copper and selenium co-contaminated soil.

    PubMed

    Hu, Bin; Liang, Dongli; Liu, Juanjuan; Lei, Lingming; Yu, Dasong

    2014-12-01

    This study aims to explore the effects of the distribution, transformation and bioavailability of different fractions of copper (Cu) and selenium (Se) in co-contaminated soils on soil enzymes, providing references for the phytoremediation of contaminated areas and agriculture environmental protection. Pot experiments and laboratory analysis were used to investigate the transformation and bioavailability of additional Cu and Se for pakchoi (Brassica chinensis) in co-contaminated soil. In the uncontaminated soil, Cu mainly existed in residual form, whereas Se was present in residual form and in elemental and organic-sulfide matter-bound form. In the contaminated soil, Cu mainly bound to Fe-Mn oxidates, whereas Se was in exchangeable and carbonates forms. After a month of pakchoi growth, Cu tended to transfer into organic matter-bound fractions, whereas Se tended to bound to Fe-Mn oxidates. The IR (reduced partition index) value of Cu decreased as the concentrations of Cu and Se gradually increased, whereas the IR value of Se decreased as the concentration of Se increased. The IR value before pakchoi planting and after it was harvested was not affected by the concentration of exogenous Cu. Soil urease and nitrate reductase activities were inhibited by Cu and Se pollution either individually or combined in different degrees, following the order nitrate reductase>urease. The significant correlation between the IR value and soil enzyme activities suggests that this value could be used to evaluate the bioavailability of heavy metals in soil. Path analysis showed that the variations in exchangeable Cu and organic-sulfide matter-bound and elemental Se had direct effects on the activities of the two enzymes, suggesting their high bioavailability. Therefore, the IR value and the transformation of metals in soil could be used as indicators in evaluating the bioavailability of heavy metals. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Potential of plant growth promoting traits by bacteria isolated from heavy metal contaminated soils.

    PubMed

    Kumar, Vijay; Singh, Simranjeet; Singh, Joginder; Upadhyay, Niraj

    2015-06-01

    Rhizobacteria can enhance biomass production and heavy metal tolerance of plants under the stress environment. The aim of this study was to collect soil samples from different industrial sites followed by their heavy metal analysis. After performing the ICP-AES analysis of soil samples from seven different sites, bacterial strains were isolated from the soil samples of most polluted (heavy metal) site. Phylogenetic analysis of isolates based on 16S rDNA sequences showed that the isolates belonged to four species: Bacillus thuringiensis, Azotobacter chroococcum, Paenibacillus ehimensis and Pseudomonas pseudoalcaligenes. Plant growth promoting activities; siderophore production, indole acetic acid production, HCN production, and phosphate solubilisation were assayed in vitro, and statistically analysis done by using ANOVA analysis and Tukey's Honestly Significant Difference test (p ≤ 0.05). Plant growth-promoting characteristics of isolated strains were higher compared to the control Pseudomonas fluorescens (NICM 5096). In vitro study was performed to check resistance against two heavy metals of isolates. It was observed that isolated bacterial strains have higher heavy metal resistance as compared to control E. coli (NICM 2563). These isolates may cause pathogenic effects, so to avoid this risk, their antibacterial susceptibility was checked against eight antibiotics. Among the eight antibiotics, Ciprofloxacin-1 has shown higher inhibition against all the isolated bacterial strains.

  5. Heavy metals in soil at a waste electrical and electronic equipment processing area in China.

    PubMed

    Gu, Weihua; Bai, Jianfeng; Yao, Haiyan; Zhao, Jing; Zhuang, Xuning; Huang, Qing; Zhang, Chenglong; Wang, JingWei

    2017-08-01

    For the objective of evaluating the contamination degree of heavy metals and analysing its variation trend in soil at a waste electrical and electronic equipment processing area in Shanghai, China, evaluation methods, which include single factor index method, geo-accumulation index method, comprehensive pollution index method, and potential ecological risk index method, were adopted in this study. The results revealed that the soil at a waste electrical and electronic equipment processing area was polluted by arsenic, cadmium, copper, lead, zinc, and chromium. It also demonstrated that the concentrations of heavy metals were increased over time. Exceptionally, the average value of the metalloid (arsenic) was 73.31 mg kg(-1) in 2014, while it was 58.31 mg kg(-1) in the first half of 2015, and it was 2.93 times and 2.33 times higher than that of the Chinese Environmental Quality Standard for Soil in 2014 and the first half of 2015, respectively. The sequences of the contamination degree of heavy metals in 2014 and the first half of 2015 were cadmium > lead > copper > chromium > zinc and cadmium > lead > chromium > zinc > copper. From the analysis of the potential ecological risk index method, arsenic and cadmium had higher ecological risk than other heavy metals. The integrated ecological risk index of heavy metals (cadmium, copper, lead, zinc, and chromium) and metalloid (arsenic) was 394.10 in 2014, while it was 656.16 in the first half of 2015, thus documenting a strong ecological risk.

  6. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    NASA Astrophysics Data System (ADS)

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-02-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed.

  7. Distribution of Heavy Metals in Soil of Urban Ecosystems by the Example of the Oryol City

    NASA Astrophysics Data System (ADS)

    Vorobyov, S.; Kozlov, D.; Poturaeva, T.; Chernyaeva, I.

    2017-05-01

    The article deals with the impact of vehicle emissions on the distribution of heavy metals in the soils of urban ecotopes - land urban areas with similar parameters of the biosphere, the technosphere, demographic and urban development factors by the example of the Oryol city.

  8. The relationships between content of heavy metals in soil and in strawberries.

    PubMed

    Bystricka, Judita; Musilova, Janette; Trebichalsky, Pavol; Tomas, Jan; Stanovic, Radovan; Bajcan, Daniel; Kavalcova, Petra

    2016-01-01

    The work was aimed at assessment of quality of strawberry based on the contents of heavy metals as well as the possible correlations between selected heavy metals in soil and strawberries. The results revealed that from all observed metals in soil determined in aqua regia only in the case of cadmium the maximum permissible limit in comparison with the limit resulting from the Law No. 220/2004 as well as threshold values proposed by European Commission (EC) (2006) has been exceeded. In our paper the values of cadmium in the soil representing 1.86 to 2.41 times higher values than limit valid in the Slovak Republic (0.7 mg/kg) and 2.6 to 3.38 times higher in comparison to EC (0.5 mg/kg). In our study in 1 M NH4NO3 the values of lead ranged from 0.125 to 0.205 mg/kg representing values exceeded the limit valid in Slovak Republic (0.1 mg/kg) about 0.037-0.105 mg/kg. Despite exceeded values of heavy metals in soil, no values above the limit directly in strawberries when compared to Food Codex of Slovak Republic as well as to Commission Regulation 1881/2006 were recorded. Among the varieties statistically significant differences (P < 0.05) in intake of heavy metals were found.

  9. Soil Heavy Metal Pollution and Risk Assessment in Shenyang Industrial District, Northeast China

    PubMed Central

    Jiao, Xudong; Teng, Yanguo; Zhan, Yanhong; Wu, Jin; Lin, Xueyu

    2015-01-01

    To investigate the soil heavy metal pollution characteristics and ecological risk factors, 42 samples and six typical soil profiles were collected from the Shenyang industrial district in northeast China and were analyzed for contents of titanium (Ti), copper (Cu), lead (Pb), zinc (Zn), cobalt (Co), nickel (Ni), chromium (Cr) and arsenic (As). Through statistical analysis, it was found that the mean concentrations were higher than their background values (Ti = 4.77>3.8g/kg, Cu = 33.75>22.6 mg/kg, Pb = 45.95>26 mg/kg, Zn = 81.54>74.2 mg/kg, Co = 12.91>12.7 mg/kg, Ni = 32.26>26.9 mg/kg, Cr = 83.36>61 mg/kg and As = 13.69>11.2 mg/kg) but did not exceed their corresponding pollution limits for the Chinese Environmental Quality Standard for Soils (State Environmental Protection Administration of China, 1995). There were contamination hotspots that may be caused by human activities such as smelting plants and sewage irrigation. The Enrichment Factor and Ecological Risk Index were used to identify the anthropogenic contamination and ecological risks of heavy metals. Soil in the study area could be considered lightly or partially polluted by heavy metals. According to clustering analysis, distinct groups of heavy metals were discriminated between natural or anthropogenic sources. PMID:25997173

  10. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    PubMed Central

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-01-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed. PMID:26878770

  11. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil.

    PubMed

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-02-16

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed.

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

    PubMed

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

    2014-02-15

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

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

    EPA Science Inventory

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

  14. Influence of plow pan on the enrichment and depletion of heavy metals in the surface soils

    USDA-ARS?s Scientific Manuscript database

    Hydropedology is a new discipline that uses pedological information to understand the soil water movement, and thus the storage, transformation, and transportation of heavy metals (HMs). However, limited studies have investigated how the hydropedological feature, for example the water-restrictive so...

  15. Heavy metals in urban soils of East St. Louis, IL. Part II: Leaching characteristics and modeling.

    PubMed

    Kaminski, M D; Landsberger, S

    2000-09-01

    The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.

  16. Heavy Metals in Urban Soils of East St. Louis, IL Part II: Leaching Characteristics and Modeling.

    PubMed

    Kaminski, Michael D; Landsberger, Sheldon

    2000-09-01

    The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.

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

    EPA Science Inventory

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

  18. Roles of black carbon on the fate of heavy metals and agrochemicals in soil

    USDA-ARS?s Scientific Manuscript database

    Char(coal) and other black carbon materials can comprise up to 35% of total organic carbon in US agricultural soils, and are known to strongly and often irreversibly bind contaminants including heavy metals. Black carbon has received renewed interests in recent years as a solid co-product formed du...

  19. Soil heavy metal pollution and risk assessment in Shenyang industrial district, Northeast China.

    PubMed

    Jiao, Xudong; Teng, Yanguo; Zhan, Yanhong; Wu, Jin; Lin, Xueyu

    2015-01-01

    To investigate the soil heavy metal pollution characteristics and ecological risk factors, 42 samples and six typical soil profiles were collected from the Shenyang industrial district in northeast China and were analyzed for contents of titanium (Ti), copper (Cu), lead (Pb), zinc (Zn), cobalt (Co), nickel (Ni), chromium (Cr) and arsenic (As). Through statistical analysis, it was found that the mean concentrations were higher than their background values (Ti = 4.77>3.8g/kg, Cu = 33.75>22.6 mg/kg, Pb = 45.95>26 mg/kg, Zn = 81.54>74.2 mg/kg, Co = 12.91>12.7 mg/kg, Ni = 32.26>26.9 mg/kg, Cr = 83.36>61 mg/kg and As = 13.69>11.2 mg/kg) but did not exceed their corresponding pollution limits for the Chinese Environmental Quality Standard for Soils (State Environmental Protection Administration of China, 1995). There were contamination hotspots that may be caused by human activities such as smelting plants and sewage irrigation. The Enrichment Factor and Ecological Risk Index were used to identify the anthropogenic contamination and ecological risks of heavy metals. Soil in the study area could be considered lightly or partially polluted by heavy metals. According to clustering analysis, distinct groups of heavy metals were discriminated between natural or anthropogenic sources.

  20. Influence of pyrolysis temperature on biochar property and function as heavy metal sorbent in soil

    USDA-ARS?s Scientific Manuscript database

    While large-scale soil amendment of biochars continues to receive interests for enhancing crop yields and to remediate contaminated sites, systematic study is lacking on how biochar properties translate into purported functions such as the heavy metal sequestration. In this study, cottonseed hulls ...

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

    PubMed

    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

  2. [Application potential of siderophore-producing rhizobacteria in phytoremediation of heavy metals-contaminated soils: a review].

    PubMed

    Wang, Ying-Li; Lin, Qing-Qi; Li, Yu; Yang, Xiu-Hong; Wang, Shi-Zhong; Qiu, Rong-Liang

    2013-07-01

    Siderophore-producing rhizobacteria (SPR) are a group of plant growth-promoting rhizobacteria, being able to play an important role in assisting the phytoremediation of heavy metals-contaminated soils. Based on the comprehensive analysis of related researches at home and abroad, this paper elaborated the functions of SPR in alleviating the heavy metals stress and toxicity to plants and the mechanisms of SPR in improving the heavy metals bioavailability in soil, and indicated that SPR had good application potential in promoting the plant growth in heavy metals-contaminated soils and reinforcing the heavy metals accumulation in plants. The contradictory phenomena of SPR in increasing or decreasing heavy metals accumulation in plants, which existed in current researches, were also analyzed. Aiming at the deficiencies in current researches, it was suggested that in the future researches, the mechanisms of the interactions between SPR and plants, especially hyperaccumulators, should be further studied, the key factors affecting the heavy metals complexation and mobilization in soil by siderophores should also be further clarified, the effects of siderophores on the heavy metals bioavailability and its subsequent influence on the heavy metals uptake by plants should be comprehensively considered, and the measures for improving the colonization of SPR in heavy metals-contaminated soil should be explored.

  3. Quantitative relations between soil heavy metal contamination and landscape pattern in Wuxi, China

    NASA Astrophysics Data System (ADS)

    Zhu, Ming; Pu, Lijie; Xu, Yan

    2017-04-01

    Land use practices changed landscape pattern and meanwhile, brought forth numerous environmental problems including heavy metal contamination in soil. In this study, we investigated the quantitative relations between soil heavy metal contamination and its surrounding landscape pattern based on topsoil samples and land use map of Wuxi in 2009. The results of vector fitting with Redundancy analysis in R package vegan showed that Percent Coverage of build-up area (PCB) within 2500 m, Perimeter-Area Fractal Dimension (PAFD) within 2500 m, Edge Density (ED) within 2500 m, Patch Density (PD) within 200 m, Percent Coverage of wetland (PCW) within 2000 m and Patch Cohesion (PC) within 200 m significantly affected the contents of heavy metal elements. The results of Stepwise regression suggested that increase of build-up area and fragmentation would increase Cu and Zn, while increase of wetland would decrease the contents of As and Cu. PAFD was negative with Cd, Hg, Pb and Zn.

  4. Analysis of Soil Heavy Metal Pollution and Pattern in Central Transylvania

    PubMed Central

    Suciu, Ioan; Cosma, Constantin; Todică, Mihai; Bolboacă, Sorana D.; Jäntschi, Lorentz

    2008-01-01

    The concentration of five soil heavy metals (Pb, Co, Cr, Cu, Hg) was measured in forty sampling sites in central Transylvania, Romania, regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using the Inductively Coupled Plasma Spectrometry method. Data were verified by using the Neutron Activation Analysis method. In some locations, the concentration for the investigated heavy metals exceeds the concentration admitted by the Romanian guideline. The highest concentration of lead (1521.8 ppm) and copper (1197.6 ppm) was found in Zlatna. The highest concentration of chromium was found in Târnăveni (1080 ppm). The maximum admitted concentrations in the sensitive areas revealed to be exceed from five to forty times. PMID:19325760

  5. Heavy Metal Contents of Soils, Durum and Bread Wheats in Harran Plain, Southeast Turkey

    NASA Astrophysics Data System (ADS)

    Büyükkılıç Yanardaǧ, Asuman

    2013-04-01

    Soils are vital for regulating the biological effects and mobility of metals in nature. Iron and zinc are some of the essential nutrients for plants and animals, while other metals are potentially toxic such as lead and cadmium. Toxic heavy metals (HMs) can be taken up easily by organisms. HMs inputs to soil via the application of metal-contained fertilizers often exceed outputs in crops and drainage waters, thus toxic HMs content in many agricultural soils tends to be gradually increasing. Thus adverse human health effects due to soil-plant and plant-human transfer of HMs have been enhanced. HMs may cause harmful effects on human health due to the ingestion of food grain grown in soils. The objectives of this study were (1) to understand the chemistry of metals in soils for managing their agricultural and ecological impacts, (2) to identify metal uptakes of different genotypes of wheat. Concentrations of HMs (Cd, Zn, Ni, Mn, Cu, Mo, Pb) in wheat were investigated in different agricultural areas in Southeast, Turkey. The results showed that concentrations of HMs were in following order: Mn>Ni>Zn>Cu>Pb>Mo>Cd in surface and next to surface soil and Mn>Zn>Cu>Pb> Ni>Mo>Cd in wheat, respectively. HMs concentrations of several soil samples exceeded the permissible limits of Europe standard except for Ni and Mn. In addition, concentration of Cd, Zn, Cu, and Pb were higher in bread wheat than in durum wheat; however, concentration of Mn, Ni and Mo were higher in durum wheat than in bread wheat. Unusual amount of heavy metals found in some fertilizers used in the Southeast region of Turkey, it becomes an important subject to determine the amount of metals added to the soil every year. Heavy metals uptake by plants still remains to be an interest for researchers. As the heavy metals contents of plants were below the threshold levels, we conclude that the quality of wheat is high and it should receive attention in national and international markets. Keywords: Heavy Metals

  6. Sequential extraction of heavy metals in soils from a copper mine

    NASA Astrophysics Data System (ADS)

    Arenas, Daniel; Lago, Manoel; Vega, Flora; Andrade, Luisa

    2013-04-01

    Metal mining produces a large amount of waste materials where mine soils can be formed. They use to have important limitations for plant development like extreme pH and low organic matter among others. On metal mines they usually have problems of pollution by heavy metals (Asensio et al., 2013) generally concerning more than one metal. At Touro (Galicia, Spain) copper was mining from 1973 to 1988. Nowadays, there are soils formed on the tailings formed with waste and thick materials coming from copper extraction and on the settling pond since it is emerged and dry. They are partly exposed to weathering and the iron, copper, sulphides and H+ can be released causing acid mine drainage and heavy metal solubilization. Since heavy metals can adsorb onto the soil, runoff into rivers or lakes or leach in the groundwater (Mulligan et al., 2001) it is very important to study the soils mechanisms involved in both retention and solubility of heavy metals. The sequential extraction procedures allow to better understand them since the chosen extractions attempt to minimize solubilization of other soil fractions even none of them is completely specific (Mulligan et al., 2001). At Touro mine, five soils were sampled and analysed for those properties known as heavy metal retention determiners. The distribution of Cr, Cu, Mn, Ni, Pb and Zn among geochemical soil phases was analysed following the modified sequential extraction technique of Shuman (1979, 1985). The concentration in the extractions was analysed by ICP-OES. The results show that most of the heavy metal content is associated to the residual fraction in all soils Cr (85-92%), Cu (53-81%), Mn (80-98%), Ni (86-96%), Pb (47-81%) and Zn (85-95%). The high crystalline Fe-oxides content also plays an important role, specially for Cu (18-22% of the total Cu). The amount of heavy metals associated to soil organic matter is very low (Pb and Cu: <3%, Zn, Ni, Mn and Cr: <0.5%) and the same happens with the exchangeable form (Cu: 1

  7. Spatial distribution of heavy metals in soil, water, and vegetables of farms in Sanandaj, Kurdistan, Iran.

    PubMed

    Maleki, Afshin; Amini, Hassan; Nazmara, Shahrokh; Zandi, Shiva; Mahvi, Amir Hossein

    2014-01-01

    Heavy metals are ubiquitous elsewhere in nature and their measurement in environment is necessary to develop health management strategies. In this study, we aimed to find out concentrations and spatial patterns of heavy metals in main farms of Sanandaj in Kurdistan, Iran. Over May to October 2012, six farms were selected to analyze concentrations and spatial patterns of several heavy metals, namely aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in their soil, irrigation water, and edible vegetables. Overall, 36 samples of soil and water and 72 samples of vegetables including coriander (Coriandrum sativum), dill (Anethum graveolens), radish (Raphanus sativus) root and radish leaf were collected. The concentrations of metals were determined by inductively coupled plasma optical emission spectrometry. The spatial surfaces of heavy metals were created using geospatial information system. The order of metals in soil was Al > Zn > Ni > Cu > Cr > Pb > Co > As > Cd while in water it was Cr > Co > Zn > Pb > Cu > Ni > Al = As = Cd. The order of heavy metals in vegetables was Al > Zn > Cu > Cr > Ni > Pb > Co > As > Cd. Totally, the minimum concentrations of Al, Cu, Pb, and Zn were found in radish root while the maximum of Al, Co, Cr, and Ni were found in radish leaf. The minimum concentrations of Cd and Cr and maximum concentrations of Cu and Zn were also deciphered in dill. Noteworthy, coriander had the minimum concentrations of Co and Ni. The concentrations of Cr and Pb in vegetables were more than maximum allowable limits of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). In summary, albeit the concentrations of heavy metals in soil and water samples were below FAO and the WHO standards, vegetables were contaminated by chromium and lead.

  8. Equilibrium partitioning of heavy metals in Dutch field soils. 1: Relationship between metal partition coefficients and soil characteristics

    SciTech Connect

    Janssen, R.P.T.; Peijnenburg, W.J.G.M.; Posthuma, L.; Hoop, M.A.G.T. Van Den

    1997-12-01

    Twenty Dutch soils were sampled at sites that were expected to have elevated levels of heavy metals compared to background values. Field-based partition coefficients (K{sub p}) for As, Cd, Cr, Cu, Ni, Pb, and Zn were determined by calculating the ratio of the amount of metal extracted by concentrated HNO{sub 3} to the metal concentration in the pore water. K{sub p} values varied widely with metal and soil type and correlated well with soil pH. To a lesser extent amorphous Fe-content and dissolved organic carbon (DOC) also explained part of the variation in K{sub p} values. Thereupon, regression equations based on easily obtainable soil characteristics were derived. External validation of the regression equations showed that predicted log K{sub p} values were in agreement with measured values.

  9. Geochemical cartography as a tool for assessing the degree of soil contamination with heavy metals in Poland

    NASA Astrophysics Data System (ADS)

    Szymon Borkowski, Andrzej; Kwiatkowska-Malina, Jolanta

    2016-04-01

    Spatial disposition of chemical elements including heavy metals in the soil environment is a very important information during preparation of the thematic maps for the environmental protection and/or spatial planning. This knowledge is also essential for the earth's surface and soil's monitoring, designation of areas requiring improvement including remediation. The main source of anthropogenic pollution of soil with heavy metals are industry related to the mining coal and liquid fuels, mining and metallurgy, chemical industry, energy production, waste management, agriculture and transport. The geochemical maps as a kind of specific thematic maps made on the basis of datasets obtained from the Polish Geological Institute's resources allow to get to know the spatial distribution of different chemical elements including heavy metals in soil. The results of the research carried out by the Polish Geological Institute showed strong contamination in some regions in Poland mainly with arsenic, cadmium, lead and nickel. For this reason it was the point to prepare geochemical maps showing contamination of soil with heavy metals, and determine main sources of contamination and zones where heavy metals concentration was higher than acceptable contents. It was also presented a summary map of soil contamination with heavy metals. Additionally, location of highly contaminated zones was compiled with predominant in those areas types of arable soils and then results were thoroughly analyzed. This information can provide a base for further detailed studies on the soil contamination with heavy metals.

  10. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil.

    PubMed

    Grytsyuk, N; Arapis, G; Perepelyatnikova, L; Ivanova, T; Vynograds'ka, V

    2006-02-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

  11. Heavy metals and hydrocarbons contents in soils of urban areas of Yamal autonomous region (Russia)

    NASA Astrophysics Data System (ADS)

    Alekseev, Ivan; Abakumov, Evgeny; Shamilishvili, George

    2016-04-01

    This investigation is devoted to evaluation of heavy metals and hydrocarbons contents in soils of different functional localities within the Yamalo-Nenets autonomous region (YaNAR, North-Western Siberia, Russia). Geo-accumulation indices Igeo (Müller 1988) were calculated in order to assess soil contamination levels with heavy metals (Cu, Pb, Cd, Zn, Ni, As, Hg) in the studied settlements: Harsaim, Aksarka, Labytnangy, Harp and Salekhard. The degree of soil pollution was assessed according to seven contamination classes (Förstner et al. 1990) in order of increasing numerical value of the index. Cd's regional soil background concentrations of the Yamal peninsula (Moskovchenko 2010), Hg's Earth crust clarke (Greenwood & Earnshaw 2008) and concentrations of the rest trace elements in natural sandy soil from the Beliy island, YaNAR (Tomashunas & Abakumov, 2014) were used in calculations. In general terms, obtained Igeo values in all samples were under or slightly above the 0 level, indicating low to moderate pollution of the studied soils. However, considerable Igeo values of Zn, Pb and Ni were revealed in several samples, suggesting different soil pollution levels, namely: Zn Igeo in Harsaim soil sample of 2.22 - moderate polluted to highly polluted soil; Pb Igeo in Aksarka soil sample of 4.04 - highly polluted to extremely polluted soil; Ni Igeo in Harp soil sample of 4.34 - highly polluted to extremely polluted soil. Soil contamination level was additionally evaluated, comparing with the maximal permissible concentrations (MPCs) of the trace elements in soil (SANPIN 4266-87), established by the national legislation. Almost all samples exceeded the MPC for As in soils (2 mg•kg-1). Concentrations of Ni in several soil samples taken in Harp were 19 times higher than recommended level (20 mg•kg-1). Moderate excess of Zn, Pb and Cu MPCs was also noted. Data obtained will be used in further environmental researches and environmental management purposes in this key

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

    PubMed Central

    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

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

    PubMed

    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. Ecotoxicological and microbiological characterization of soils from heavy-metal- and hydrocarbon-contaminated sites.

    PubMed

    Płaza, Grazyna A; Nałecz-Jawecki, Grzegorz; Pinyakong, Onruthai; Illmer, Paul; Margesin, Rosa

    2010-04-01

    The aims of this study were to characterize soils from industrial sites by combining physicochemical, microbiological, and ecotoxicological parameters and to assess the suitability of these assays for evaluation of contaminated sites and ecological risk assessment. The soil samples were taken from long-term contaminated sites containing high amounts of heavy metals (sites 1 and 2) or petroleum hydrocarbons (site 3) located in the upper Silesia Industrial Region in southern Poland. Due to soil heterogeneity, large differences between all investigated parameters were measured. Microbiological properties revealed the presence of high numbers of viable hetrotrophic microorganisms. Soil enzyme activities were considerably reduced or could not be detected in contaminated soils. Activities involved in N turnover (N mineralization and nitrification) were significantly (P < 0.05) higher in samples from the metal-contaminated sites than in samples from the hydrocarbon-contaminated site, whereas the opposite was observed for phosphatase activity. The Microtox test system appeared to be the most appropriate to detect toxicity and significant differences in toxicity between the three sites. The Ostracodtoxkit test was the most appropriate test system to detect toxicity in the hydrocarbon-contaminated soil samples. Correlation analysis between principal components (obtained from factor analysis) determined for physicochemical, microbiological, and ecotoxicological soil properties demonstrated the impact of total and water-extractable contents of heavy metals on toxicity.

  15. Assessment of heavy metal pollution in soils and crops of industrial sites, Isfahan, Iran.

    PubMed

    Moradi, Anahita; Honarjoo, Naser; Fallahzade, Jaber; Najafi, Payam

    2013-01-15

    This study was planned to investigate the concentrations of heavy metal in soils and crops and estimate the potential health risks of metals to humans via consumption of crops grown at industrial sites (Zarrinshahr and Mobarakeh) and control site (Natanz) in Isfahan province, central Iran. The soils and food crops (wheat and rice grains and onion bulbs) were digested by acid digestion method and then were analyzed for Mn, Cu and Zn by atomic absorption spectrophotometer. The results showed that the concentration of Zn in the soils of Mobarakeh was higher than the soils of Zarrinshahr and Natanz. The concentrations of Mn in the soils of Natanz and Mobarakeh were higher than the soils of Zarrinshahr. The concentration of Zn in the wheat was significantly higher than that rice and onion crops. The concentrations of Zn and Cu were higher in wheat crop in Mobarakeh compared with other cases. Results of this study revealed that the concentrations of Zn, Cu and Mn in the soils of studied sites were below than the maximum allowable levels. The average concentration of Zn, Cu and Mn metals in rice, wheat and onion crops were below than the maximum allowable levels of WHO guideline. The estimated daily intakes of heavy metals from the crops of three sites were lower than the tolerable daily intake recommended by FAO/WHO. Consequently, these crops cannot be an important source of Zn, Cu and Mn for risk to human health.

  16. Toxicity and DNA damage in tobacco and potato plants growing on soil polluted with heavy metals.

    PubMed

    Gichner, Tomás; Patková, Zdenka; Száková, Jirina; Demnerová, Katerina

    2006-11-01

    Heterezygous tobacco (Nicotiana tabacum var. xanthi) and potato (Solanum tuberosum var. Korela) plants were cultivated on soil from the site Strimice which is highly polluted with heavy metals and on nonpolluted soil from the recreational site Jezerí, both in North Bohemia, Czech Republic. The total content, the content of bioavailable, easily mobile, and potentially mobile components of heavy metals (Cd, Cu, Pb, and Zn) in the tested soils, and the accumulation of these metals in the above-ground biomass and roots of tested plants were analyzed by flame atomic absorption spectrometry or flameless atomic absorption spectrometry. The average tobacco leaf area and potato plant height were significantly reduced in plants growing on the polluted soil. We have measured the DNA damage in nuclei of leaves of both plant species using the Comet assay. A small but significant increase in DNA damage was noted in plants growing on the polluted soil versus controls. As the tobacco and potato plants with increased DNA damage were severely injured (inhibited growth, distorted leaves), this increase may be associated with necrotic or apoptotic DNA fragmentation. No increase in the frequency of somatic mutation was detected in tobacco plants growing on the polluted soil. Thus, the polluted soil probably induced toxic but not genotoxic effects on tobacco and potato plants.

  17. Assessing heavy metal sources in sugarcane Brazilian soils: an approach using multivariate analysis.

    PubMed

    da Silva, Fernando Bruno Vieira; do Nascimento, Clístenes Williams Araújo; Araújo, Paula Renata Muniz; da Silva, Luiz Henrique Vieira; da Silva, Roberto Felipe

    2016-08-01

    Brazil is the world's largest sugarcane producer and soils in the northeastern part of the country have been cultivated with the crop for over 450 years. However, so far, there has been no study on the status of heavy metal accumulation in these long-history cultivated soils. To fill the gap, we collect soil samples from 60 sugarcane fields in order to determine the contents of Cd, Cr, Cu, Ni, Pb, and Zn. We used multivariate analysis to distinguish between natural and anthropogenic sources of these metals in soils. Analytical determinations were performed in ICP-OES after microwave acid solution digestion. Mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 1.9, 18.8, 6.4, 4.9, 11.2, and 16.2 mg kg(-1), respectively. The principal component one was associated with lithogenic origin and comprised the metals Cr, Cu, Ni, and Zn. Cluster analysis confirmed that 68 % of the evaluated sites have soil heavy metal concentrations close to the natural background. The Cd concentration (principal component two) was clearly associated with anthropogenic sources with P fertilization being the most likely source of Cd to soils. On the other hand, the third component (Pb concentration) indicates a mixed origin for this metal (natural and anthropogenic); hence, Pb concentrations are probably related not only to the soil parent material but also to industrial emissions and urbanization in the vicinity of the agricultural areas.

  18. Rapid detection of soils contaminated with heavy metals and oils by laser induced breakdown spectroscopy (LIBS).

    PubMed

    Kim, Gibaek; Kwak, Jihyun; Kim, Ki-Rak; Lee, Heesung; Kim, Kyoung-Woong; Yang, Hyeon; Park, Kihong

    2013-12-15

    A laser induced breakdown spectroscopy (LIBS) coupled with the chemometric method was applied to rapidly discriminate between soils contaminated with heavy metals or oils and clean soils. The effects of the water contents and grain sizes of soil samples on LIBS emissions were also investigated. The LIBS emission lines decreased by 59-75% when the water content increased from 1.2% to 7.8%, and soil samples with a grain size of 75 μm displayed higher LIBS emission lines with lower relative standard deviations than those with a 2mm grain size. The water content was found to have a more pronounced effect on the LIBS emission lines than the grain size. Pelletizing and sieving were conducted for all samples collected from abandoned mining areas and military camp to have similar water contents and grain sizes before being analyzed by the LIBS with the chemometric analysis. The data show that three types of soil samples were clearly discerned by using the first three principal components from the spectral data of soil samples. A blind test was conducted with a 100% correction rate for soil samples contaminated with heavy metals and oil residues. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Hydrogenic heavy metal pollution of alluvial soils in the city of Perm

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Vasil'Ev, A. A.; Vlasov, M. N.

    2008-11-01

    The differences in the sources and compositions of the pollutants among the alluvial soils within the city of Perm were revealed. Heavy metal pollution of hydrogenic origin is caused by unpurified sewage water. The main source of pollution of the urbanozems and replantozems of the city is the aerial input of heavy metals. The lead content in the alluvial soils of the city was twice lower and the mean Zn and Ni contents were 1.5 and 4.0 times higher than in the urbanozems and replantozems, respectively. The concentrations of Sr, Zn, Ni, Cu, and Cr did not correlate positively with the content of clay particles in the fine earth of the alluvial soils. The higher pollution of the light-textured soils showed that, nowadays, its main source was sewage water but not sludge. In the alluvial soils, small Fe-rohrensteins are formed. They serve as microgeochemical barriers for some part of the microelements. The Pb and Zn contents in the rohrensteins of the soils of the Las’va river basin reached 440 and 890 mg/kg, respectively. In the upper horizon of this soil, the contents of Pb and Zn in the rohrensteins were 42 and 17% of their concentration in the fine earth, respectively.

  20. Heavy metals, organics and radioactivity in soil of western Serbia.

    PubMed

    Dugalic, Goran; Krstic, Dragana; Jelic, Miodrag; Nikezic, Dragoslav; Milenkovic, Biljana; Pucarevic, Mira; Zeremski-Skoric, Tijana

    2010-05-15

    Western Serbia is a region well-known for potato production. Concentrations of selected metals, polycyclic aromatic hydrocarbons (PAHs) and radioactivity were measured in the soil in order to evaluate the quality and characteristics. The examined soils (Luvisol and Pseudogley) showed unsuitable agrochemical characteristics (acid reaction, low content of organic matter and potassium). Some samples contained Ni, Mn and Cr above the maximal permissible concentration (MPC). The average concentration of total PAHs was 1.92 mg/kg, which is larger than the maximal permissible concentration in Serbia but below the threshold values in the European Union for food production. The average radioactivity of (238)U, (226)Ra, (232)Th, (40)K and the fission product (137)Cs were 60.4+/-26.2, 33.2+/-13.4, 49.1+/-18.5, 379+/-108 and 36.4+/-23.3 Bq/kg. Enhanced radioactivity in the soils was found. The total absorbed dose rate in air above the soil at 1m height calculated for western Serbia was 73.4 nGy/h and the annual effective dose was 90 microSv, which are similar to earlier reports for the study region.

  1. Spatial distribution of heavy metals in surface soil, plant and mushroom beside high-frequency road

    NASA Astrophysics Data System (ADS)

    Krbić, Biljana Å.; Milovac, Snežana; Stošić, Dušan; Zorić, Miroslav; Matavulj, Milan

    2010-05-01

    One of the undesirable aspects of urbanization process is the introduction of potentially harmful pollutants into environment. Urban soils are often contaminated by metals deriving from industry, transportation and other human activities. In this study, concentration of heavy metals were investigated in roadside surface soil, linden tree bark (Tilia sp.), mushroom Schizophyllum commune and dust samples collected at different distances (0.2 - 200 m) from main high-frequency road. The samples were microwave digested in accordance to US EPA 3051 method and analyzed by flame (Cd, Cu, Co, Fe, Ni, Mn, Pb and Zn), graphite furnace (Cr) and cold vapor (Hg) atomic absorption spectrometry. The results of the analysis were used to determine major sources and distribution of heavy metals pollution. The obtained results showed significant decrease of traffic-related metals (Fe, Zn, Pb, Ni, Cu and Cd) in soil samples with increasing distance from road edge. In order to assess possible pollution, heavy metal contents in soil were compared with the National legislation and Netherlands soil quality standards. Also, elevated concentrations of traffic-related metals, especially Pb and Cr in analyzed tree bark, mushroom and dust samples, indicate the obvious roadside contamination whose primary contributors appear to be vehicular local traffic. In addition, Index of Bioaccumulation (IBA) was calculated in order to estimate plant and mushroom ability of heavy metals accumulation. Assessment of statistical differences among samples was performed by one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) test. Moreover, Principal Component Analysis (PCA) was performed on the heavy metals content allowed a meaningful classification of the samples according to the main sources of pollution.

  2. [Effects of heavy metals pollution on soil microbial communities metabolism and soil enzyme activities in coal mining area of Tongchuan, Shaanxi Province of Northwest China].

    PubMed

    Guo, Xing-Liang; Gu, Jie; Chen, Zhi-Xue; Gao, Hua; Qin, Qing-Jun; Sun, Wei; Zhang, Wei-Juan

    2012-03-01

    This paper studied the metabolism of soil microbes, functions of soil microbial communities, and activities of soil enzymes in a coal mining area of Tongchuan. In the coal mining area, the concentrations of soil Cu, Zn, Cd, and Pb were significantly higher than those in the non-mining area, of which, Cd contributed most to the heavy metals pollution. By adopting Biolog method combining with principal component analysis (PCA) and cluster analysis, it was found that the metabolic characteristics of different soil microbial communities varied significantly with increasing soil heavy metals pollution, and the variation was mainly manifested in the metabolic patterns of carbon sources such as saccharides and amino acids. In slightly and moderately polluted soils, the utilization of carbon sources by soil microbial communities was activated; while in heavily polluted soils, the carbon sources utilization was inhibited. The activities of soil urease, protease, alkaline phosphatase, and catalase all tended to decline with intensifying soil heavy metals pollution. The soil urease, protease, alkaline phosphatase, and catalase activities in the coal mining area were 50.5%-65.1%, 19.1%-57.1%, 87.2%-97.5%, and 77.3%-86.0% higher than those in the non-mining area, respectively. The activities of soil sucrase and cellulase were activated in slightly and moderately polluted soils, but inhibited in heavily polluted soils.

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

    PubMed

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

    2012-02-15

    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.

  4. Total and available heavy metal concentrations in soils of the Thriassio plain (Greece) and assessment of soil pollution indexes.

    PubMed

    Massas, Ioannis; Kalivas, Dionisios; Ehaliotis, Constantions; Gasparatos, Dionisios

    2013-08-01

    The Thriassio plain is located 25 km west of Athens city, the capital of Greece. Two major towns (Elefsina and Aspropyrgos), heavy industry plants, medium to large-scale manufacturing, logistics plants, and agriculture comprise the main land uses of the studied area. The aim of the present study was to measure the total and available concentrations of Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe in the top soils of the plain, and to asses soil contamination by these metals by using the geoaccumulation index (I geo), the enrichment factor (EF), and the availability ratio (AR) as soil pollution indexes. Soil samples were collected from 90 sampling sites, and aqua regia and DTPA extractions were carried out to determine total and available metal forms, respectively. Median total Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe concentrations were 78, 155, 81, 112, 24, 321, 834, 38, and 16 × 10(3) mg kg(-1), respectively. The available fractions showed much lower values with medians of 0.4, 5.6, 1.7, 6.9, 0.8, 5.7, 19.8, 2.1, and 2.9 mg kg(-1). Though median total metal concentrations are not considered as particularly high, the I geo and the EF values indicate moderate to heavy soil enrichment. For certain metals such as Cr, Ni, Cu, and Ba, the different distribution patterns between the EFs and the ARs suggest different origin of the total and the available metal forms. The evaluation of the EF and AR data sets for the soils of the two towns further supports the argument that the EFs can well demonstrate the long-term history of soil pollution and that the ARs can adequately portray the recent history of soil pollution.

  5. Short-Term Effects of Low-Level Heavy Metal Contamination on Soil Health Analyzed by Nematode Community Structure

    PubMed Central

    Park, Byeong-Yong; Lee, Jae-Kook; Ro, Hee-Myong; Kim, Young Ho

    2016-01-01

    The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, 1/42, 1/43, and 0] × maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4–5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2–5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals. PMID:27493608

  6. Short-Term Effects of Low-Level Heavy Metal Contamination on Soil Health Analyzed by Nematode Community Structure.

    PubMed

    Park, Byeong-Yong; Lee, Jae-Kook; Ro, Hee-Myong; Kim, Young Ho

    2016-08-01

    The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, 1/4(2), 1/4(3), and 0] × maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4-5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2-5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals.

  7. Soil and vegetables enrichment with heavy metals from geological sources in Gilgit, northern Pakistan.

    PubMed

    Khan, Sardar; Rehman, Shafiqur; Khan, Anwar Zeb; Khan, M Amjad; Shah, M Tahir

    2010-10-01

    This study was conducted to investigate the concentrations of heavy metals in soil and vegetables, and human health risks through ingestion of contaminated vegetables. Soil and vegetable samples were collected from different locations in Gilgit, northern Pakistan, and analyzed for Cd, Cu, Ni, Pb and Zn. Plant transfer factors (PTF), daily intake of metals (DIM) and health risk index (HRI) were also calculated. The concentrations of Cd, Cu and Zn exceeded their respective permissible limits in soil samples. The highest concentrations of Cu, Ni, Pb and Zn were observed in the edible parts of Malva neglecta, Brassica oleracea, Mintha sylvestris and Brassica campestris, respectively. PTF values were lower for all the selected heavy metals, except for Cd. Furthermore, the HRI values were within the safe limit (<1) except for Pb; therefore, the health risks of metals through ingestion of vegetables were of great concern in the study area. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Heavy Metals in Soil and Crops of an Intensively Farmed Area: A Case Study in Yucheng City, Shandong Province, China

    PubMed Central

    Jia, Lin; Wang, Wuyi; Li, Yonghua; Yang, Linsheng

    2010-01-01

    Yucheng City is located in northwestern Shandong Province, China, and is situated on the Huang-Huai-Hai Plain, the largest alluvial plain in China. In this study, 86 surface soil samples were collected in Yucheng City and analyzed for cation exchange capacity (CEC), soil organic matter (SOM), pH, available phosphorus (avail. P), phosphorus (P), aluminum (Al), and iron (Fe). These soils were also analyzed for ‘total’ chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb), together with 92 wheat samples and 37 corn samples. There was no obvious heavy metal contamination in the soil and irrigation water. But the long-term accumulation of heavy metals in soil has lead to an increase of Ni, As, Hg and Pb concentrations in some of wheat and corn samples and Cd in wheat samples. Because of the numerous sources of soil heavy metals and the lower level of heavy metal in irrigation water, there is no significant relation between soil heavy metal concentrations and irrigation water concentrations. Cr, Ni were mainly from the indigenous clay minerals according to multivariate analysis. Little contribution to soil heavy metal contents from agricultural fertilizer use was found and the local anomalies of As, Cd, Hg, Pb in wheat and corn grain are attributed to the interactive effects of irrigation and fertilizer used. Aerial Hg, however may also be the source of Hg for soil, wheat and corn. PMID:20616981

  9. Distribution of Heavy Metals in the Soils Associated with the Commonly Used Pesticides in Cotton Fields

    PubMed Central

    Shafiq, Musharaf; Chotana, Ghayoor Abbas

    2016-01-01

    Agricultural soils contain both heavy metals and pesticides originating from various agricultural practices. It is quite important to study the relationships between these two classes of compounds. To accomplish this, 52 soil samples were collected from cotton fields and analyzed for their metal contents (Ni, Cu, Co, Pb, Cr, and Cd) and levels of most commonly used pesticides (imidacloprid, acetamiprid, and emamectin). FAAS was used for metal estimation and the pesticides were determined by HPLC equipped with UV detector. The results of the study revealed slightly enhanced levels of Ni and Cd in these samples while the rest of the metals were present within tolerable range. Acetamiprid residues in soil were strongly positively correlated with Cu and negatively correlated with Cr. Similarly, imidacloprid in soil was negatively correlated with Ni. Thus it was evidenced that Cu stabilizes acetamiprid while Cr and Ni facilitate the degradation of acetamiprid and imidacloprid in the soil. PMID:27051560

  10. Distribution of Heavy Metals in the Soils Associated with the Commonly Used Pesticides in Cotton Fields.

    PubMed

    Tariq, Saadia Rashid; Shafiq, Musharaf; Chotana, Ghayoor Abbas

    2016-01-01

    Agricultural soils contain both heavy metals and pesticides originating from various agricultural practices. It is quite important to study the relationships between these two classes of compounds. To accomplish this, 52 soil samples were collected from cotton fields and analyzed for their metal contents (Ni, Cu, Co, Pb, Cr, and Cd) and levels of most commonly used pesticides (imidacloprid, acetamiprid, and emamectin). FAAS was used for metal estimation and the pesticides were determined by HPLC equipped with UV detector. The results of the study revealed slightly enhanced levels of Ni and Cd in these samples while the rest of the metals were present within tolerable range. Acetamiprid residues in soil were strongly positively correlated with Cu and negatively correlated with Cr. Similarly, imidacloprid in soil was negatively correlated with Ni. Thus it was evidenced that Cu stabilizes acetamiprid while Cr and Ni facilitate the degradation of acetamiprid and imidacloprid in the soil.

  11. Initial Effects of Heavy Vehicle Trafficking on Vegetated Soils

    DTIC Science & Technology

    2012-08-01

    ER D C/ CR R EL T R -1 2 -6 Optimal Allocation of Land for Training and Non-training Uses ( OPAL ) Initial Effects of Heavy Vehicle...the outdoor loam test section. Optimal Allocation of Land for Training and Non-training Uses ( OPAL ) ERDC/CRREL TR-12-6 August 2012 Initial...mal Allocation of Land for Training and Non-Training Uses ( OPAL ) Pro- gram. The work was conducted by Nicole Buck and Sally Shoop of the Force

  12. Faster extraction of heavy metals from soils using vacuum and ultrasonic energy.

    PubMed

    Pontes, Fernanda V M; Carneiro, Manuel C; de da Souza, Evelyn M F; da Silva, Lílian I D; Monteiro, Maria Inês C; Neto, Arnaldo A

    2013-01-01

    A fast vacuum- and ultrasound-assisted acid extraction of Co, Cu, Fe, Mn, Pb, and Zn from soils using a homemade system has been investigated. Preliminarily, a full factorial design with two levels and three variables (extracting agent, extraction temperature, and sonication time) was applied to optimize the extraction conditions (without vacuum) for some heavy metals (Cu, Mn, Pb, and Zn). The best results were obtained with a 3:1 HCI extraction solution, temperature of 80 degrees C, and time of 2 h. As this sonication time was too long, a vacuum pump was used to produce air bubbles in order to increase the contact between the sample and the extracting agent and to prevent the sample sedimentation. This improvement drastically reduced the sonication time to 2 min. Under these conditions, Co, Cu, Mn, and Zn were totally extracted (recoveries of 86-99%), while recoveries of 73-76 and 74% were obtained for Fe and Pb, respectively. The LOD values using flame atomic absorption spectrometry for determination of Co, Cu, Fe, Mn, Pb, and Zn were 3.2, 7.5, 37.5, 7.5, 22.5, and 3.8 micro glg, respectively. The RSDs were lower than 11% (n = 3).

  13. Lithological and land-use based assessment of heavy metal pollution in soils surrounding a cement plant in SW Europe.

    PubMed

    Cutillas-Barreiro, Laura; Pérez-Rodríguez, Paula; Gómez-Armesto, Antía; Fernández-Sanjurjo, María José; Álvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos

    2016-08-15

    We study the influence of phasing out a cement plant on the heavy metal (Hg, Pb and Cr) content in the surrounding soils, taking into account factors often neglected, such as contributions due to local lithology or land use. The range of total Hg was 10-144µg kg(-1), reaching up to 41 and 145mgkg(-1) for total contents of Pb and Cr, respectively. Forest soils showed higher concentration of Hg than prairie soils, indicating the importance of land use on the accumulation of volatile heavy metals in soils. In forest soils, total Hg showed a trend to decrease with soil depth, whereas in prairie soils the vertical pattern of heavy metal concentrations was quite homogeneous. In most cases, the distance to the cement plant was not a factor of influence in the soils content of the analyzed heavy metals. Total Pb and Cr contents in soils nearby the cement plant were quite similar to those found in the local lithology, resulting in enrichment factor values (EF's) below 2. This suggests that soil parent material is the main source of these heavy metals in the studied soils, while the contribution of the cement plant to Pb and Cr soil pollution was almost negligible. On the contrary, the soils surrounding the cement plant accumulate a significant amount of Hg, compared to the underlying lithology. This was especially noticeable in forest soils, where Hg EF achieved values up to 36. These results are of relevance, bearing in mind that Hg accumulation in soils may be an issue of environmental concern, particularly in prairie soils, where temporal flooding can favor Hg transformation to highly toxic methyl-Hg. In addition, the concurrence of acid soils and total-Cr concentrations in the range of those considered phytotoxic should be also stressed.

  14. Magnetic response of soils and vegetation to heavy metal pollution--a case study.

    PubMed

    Jordanova, Neli V; Jordanova, Diana V; Veneva, Ludmila; Yorova, Kitka; Petrovsky, Eduard

    2003-10-01

    Fast and cost-effective detection of industrial pollution can significantly promote its ecological, economic, and social assessment. A magnetometric method, used for qualitative determination of anthropogenic contamination, meets these requirements but needs further development in more quantitative terms. It could be used successfully in numerous cases when the heavy metals coexist with strongly magnetic iron oxide particles in the source dust. We present an integrated magnetic and geochemical study that examines the utility of magnetometric techniques for rapid, qualitative detection of metallic pollutants in soils and vegetation. The new aspect of our approach, in comparison with previously published articles on this subject, is the combined investigation (magnetic and geochemical) of both soils and vegetation, thus using an additional medium for employing the magnetometry as a pollution proxy at a site. The study area is a small (approximately 3 km2) region in the suburbs of Sofia (Bulgaria), with the main pollution source being a metallurgical factory. Soil samples have been taken from the topmost 20 cm from private gardens, located at different distances from the factory. Vegetation samples were taken from ryegrass (both leaves and roots) and leaves from two kinds of deciduous trees (maple and acacia). The results show that both vegetation and soils are characterized by enhanced magnetic properties, compared to background material, which is due to the presence of magnetite particles of anthropogenic origin accompanying heavy metal emissions. SEM images and microprobe analyses reveal the presence of a significant amount of particles, containing heavy metals (including iron) in vegetation samples taken close to the main pollution source. Correlation analyses show a statistically significant link (correlation coefficients ranging from 0.6 to 0.7) between magnetic susceptibility and the main heavy metals (Cu, Zn, Pb) in soil samples, indicating that the magnetic

  15. Heavy metal accumulation in wheat plant grown in soil amended with industrial sludge.

    PubMed

    Bose, Sutapa; Bhattacharyya, A K

    2008-01-01

    The concentrations of different forms of Zn, Cu, Mn, Ni, Cd, Cr, Pb and Fe metals were determined for the roadside sludge collected from pickling-rolling and electroplating industrial area. In sludge the relative abundance of total heavy metals were Fe>Mn>Cr>Ni>Cu>Pb>Zn>Cd and DTPA-extractable metals were in the order--Fe>Ni>Mn>Cr>Cu>Zn>Pb>Cd. Pot-culture experiment was conducted in soils amended with sludge (0%, 10%, 20%, 30%), pretreated with lime (0%, 0.5% and 1%). The soils were alkaline in nature (pH>8.3) with organic carbon contents were 0.34% and 0.72%. The most abundant total and bio-available metal was Fe. Two wheat seedlings were grown in each pot containing 3kg sludge-amended or control soil and the experiment was conducted till harvesting. Application of sludge increased both total and bio-available forms of metals in the soils, while lime application decreased the bioavailability of heavy metals in sludge-amended soils. The content of organic carbon showed positive correlation with all metals except Zn, Cr and Pb. CEC also showed a strong positive correlation (R2>0.7) with Fe, Mn, Cu, Ni and Cd. Though wheat plants are not accumulators, the translocation efficiency was appreciably high. The translocation factor from shoot to grain was found smaller than that of root to shoot of wheat plants. This makes an implication that the heavy metal accumulation was proportionally lesser in grain than in shoot. In, 10% sludge with 0.5% lime-amended soils; each of these toxic heavy metals was found to be within permissible range (USEPA). Hence, on the basis of present study, the best possible treatment may be recommended.

  16. Influence of pyrolysis temperature on biochar property and function as a heavy metal sorbent in soil.

    PubMed

    Uchimiya, Minori; Wartelle, Lynda H; Klasson, K Thomas; Fortier, Chanel A; Lima, Isabel M

    2011-03-23

    While a large-scale soil amendment of biochars continues to receive interest for enhancing crop yields and to remediate contaminated sites, systematic study is lacking in how biochar properties translate into purported functions such as heavy metal sequestration. In this study, cottonseed hulls were pyrolyzed at five temperatures (200, 350, 500, 650, and 800 °C) and characterized for the yield, moisture, ash, volatile matter, and fixed carbon contents, elemental composition (CHNSO), BET surface area, pH, pHpzc, and by ATR-FTIR. The characterization results were compared with the literature values for additional source materials: grass, wood, pine needle, and broiler litter-derived biochars with and without post-treatments. At respective pyrolysis temperatures, cottonseed hull chars had ash content in between grass and wood chars, and significantly lower BET surface area in comparison to other plant source materials considered. The N:C ratio reached a maximum between 300 and 400 °C for all biomass sources considered, while the following trend in N:C ratio was maintained at each pyrolysis temperature: wood≪cottonseed hull≈grass≈pine needle≪broiler litter. To examine how biochar properties translate into its function as a heavy metal (NiII, CuII, PbII, and CdII) sorbent, a soil amendment study was conducted for acidic sandy loam Norfolk soil previously shown to have low heavy metal retention capacity. The results suggest that the properties attributable to the surface functional groups of biochars (volatile matter and oxygen contents and pHpzc) control the heavy metal sequestration ability in Norfolk soil, and biochar selection for soil amendment must be made case-by-case based on the biochar characteristics, soil property, and the target function.

  17. Remote identification of soil conditions with ratioed multispectral data

    NASA Technical Reports Server (NTRS)

    Wagner, T. W.; Dillman, R.; Thomson, F.

    1973-01-01

    Some of the information concerning soils that a multispectral scanner system may provide is discussed, and a practical approach for realizing this potential is suggested. Some reflectance and emittance characteristics of soil surfaces are reviewed, and the feasibility of selectively enhancing contrasts associated with differing soil conditions is demonstrated. The simplicity of the proposed ratio technique, its relative economy, and the compatibility of the image output with conventional survey methods commends it for consideration as an operational method.

  18. Heavy metals in soils from Baia Mare mining impacted area (Romania) and their bioavailability

    NASA Astrophysics Data System (ADS)

    Roba, Carmen; Baciu, Calin; Rosu, Cristina; Pistea, Ioana; Ozunu, Alexandru

    2015-04-01

    Keywords: heavy metals, soil contamination, bioavailability, Romania The fate of various metals, including chromium, nickel, copper, manganese, mercury, cadmium, and lead, and metalloids, like arsenic, antimony, and selenium, in the natural environment is of great concern, particularly in the vicinity of former mining sites, dumps, tailings piles, and impoundments, but also in urban areas and industrial centres. Most of the studies focused on the heavy metal pollution in mining areas present only the total amounts of metals in soils. The bioavailable concentration of metals in soil may be a better predictor for environmental impact of historical and current dispersion of metals. Assessment of the metal bioavailability and bioaccessibility is critical in understanding the possible effects on soil biota. The bioavailability of metals in soil and their retention in the solid phase of soil is affected by different parameters like pH, metal amount, cation-exchange capacity, content of organic matter, or soil mineralogy. The main objectives of the present study were to determine the total fraction and the bioavailable fraction of Cu, Cd, Pb and Zn from soil in a well-known mining region in Romania, and to evaluate the influence of soil pH on the metal bioavailability in soil. The heavy metal contents and their bioavailability were monitored in a total of 50 soil samples, collected during June and July 2014 from private gardens of the inhabitants from Baia-Mare area. The main mining activities developed in the area consisted of non-ferrous sulphidic ores extraction and processing, aiming to obtain concentrates of lead, copper, zinc and precious metals. After 2006, the metallurgical industry has considerably reduced its activity by closing or diminishing its production capacity. The analysed soil samples proved to have high levels of Pb (50 - 830 mg/kg), Cu (40 - 600 mg/kg), Zn (100 - 700 mg/kg) and Cd (up to 10 mg/kg). The metal abundance in the total fraction is

  19. Special conditions for the hydrogenation of heavy hydrocarbons

    SciTech Connect

    Schliebener, C.; Wernicke, H.J.

    1982-04-13

    A procedure is claimed for thermally cracking heavy liquid hydrocarbons to produce gaseous olefins comprising a catalytic hydrogenating pretreatment; a separation of the hydrogenation product into a lighter fraction and a heavier fraction; passing the heavier fraction at least in part to a thermal cracking step to produce normally gaseous olefins; and withdrawing the lighter fraction, whereby said lighter fraction has a higher octane number.

  20. Accumulation of Heavy Metals in Vegetable Species Planted in Contaminated Soils and the Health Risk Assessment.

    PubMed

    Zhou, Hang; Yang, Wen-Tao; Zhou, Xin; Liu, Li; Gu, Jiao-Feng; Wang, Wen-Lei; Zou, Jia-Ling; Tian, Tao; Peng, Pei-Qin; Liao, Bo-Han

    2016-03-04

    The objectives of the present study were to investigate heavy metal accumulation in 22 vegetable species and to assess the human health risks of vegetable consumption. Six vegetable types were cultivated on farmland contaminated with heavy metals (Pb, Cd, Cu, Zn, and As). The target hazard quotient (THQ) method was used to assess the human health risks posed by heavy metals through vegetable consumption. Clear differences were found in the concentrations of heavy metals in edible parts of the different vegetables. The concentrations of heavy metals decreased in the sequence as leafy vegetables > stalk vegetables/root vegetables/solanaceous vegetables > legume vegetables/melon vegetables. The ability of leafy vegetables to uptake and accumulate heavy metals was the highest, and that of melon vegetables was the lowest. This indicated that the low accumulators (melon vegetables) were suitable for being planted on contaminated soil, while the high accumulators (leafy vegetables) were unsuitable. In Shizhuyuan area, China, the total THQ values of adults and children through consumption of vegetables were 4.12 and 5.41, respectively, suggesting that the residents may be facing health risks due to vegetable consumption, and that children were vulnerable to the adverse effects of heavy metal ingestion.

  1. Accumulation of Heavy Metals in Vegetable Species Planted in Contaminated Soils and the Health Risk Assessment

    PubMed Central

    Zhou, Hang; Yang, Wen-Tao; Zhou, Xin; Liu, Li; Gu, Jiao-Feng; Wang, Wen-Lei; Zou, Jia-Ling; Tian, Tao; Peng, Pei-Qin; Liao, Bo-Han

    2016-01-01

    The objectives of the present study were to investigate heavy metal accumulation in 22 vegetable species and to assess the human health risks of vegetable consumption. Six vegetable types were cultivated on farmland contaminated with heavy metals (Pb, Cd, Cu, Zn, and As). The target hazard quotient (THQ) method was used to assess the human health risks posed by heavy metals through vegetable consumption. Clear differences were found in the concentrations of heavy metals in edible parts of the different vegetables. The concentrations of heavy metals decreased in the sequence as leafy vegetables > stalk vegetables/root vegetables/solanaceous vegetables > legume vegetables/melon vegetables. The ability of leafy vegetables to uptake and accumulate heavy metals was the highest, and that of melon vegetables was the lowest. This indicated that the low accumulators (melon vegetables) were suitable for being planted on contaminated soil, while the high accumulators (leafy vegetables) were unsuitable. In Shizhuyuan area, China, the total THQ values of adults and children through consumption of vegetables were 4.12 and 5.41, respectively, suggesting that the residents may be facing health risks due to vegetable consumption, and that children were vulnerable to the adverse effects of heavy metal ingestion. PMID:26959043

  2. Electrokinetic remediation of fluorine-contaminated soil: conditioning of anolyte.

    PubMed

    Kim, Do-Hyung; Jeon, Chil-Sung; Baek, Kitae; Ko, Sung-Hwan; Yang, Jung-Seok

    2009-01-15

    The feasibility of anolyte conditioning on electrokinetic remediation of fluorine-contaminated soil was investigated with a field soil. The initial concentration of fluorine, pH and water content in the soil were 414mg/kg, 8.91 and 15%, respectively. Because the extraction of fluorine generally increased with the soil pH, the pH of the anode compartment was controlled by circulating strong alkaline solution to enhance the extraction of fluorine during electrokinetic remediation. The removal of fluorine increased with the concentration of the alkaline solution and applied current density and fluorine removed up to 75.6% within 14 days. Additionally, anolyte conditioning sharply increased the electro-osmotic flow, which enhanced the removal of fluorine in this study. In many respects, anolyte conditioning in electrokinetic remediation of fluorine-contaminated soil will be a promising technology.

  3. Influence of soil properties on heavy metal sequestration by biochar amendment: 1. Copper sorption isotherms and the release of cations.

    PubMed

    Uchimiya, Minori; Klasson, K Thomas; Wartelle, Lynda H; Lima, Isabel M

    2011-03-01

    The amendment of carbonaceous materials such as biochars and activated carbons is a promising in situ remediation strategy for both organic and inorganic contaminants in soils and sediments. Mechanistic understandings in sorption of heavy metals on amended soil are necessary for appropriate selection and application of carbonaceous materials for heavy metal sequestration in specific soil types. In this study, copper sorption isotherms were obtained for soils having distinct characteristics: clay-rich, alkaline San Joaquin soil with significant heavy metal sorption capacity, and eroded, acidic Norfolk sandy loam soil having low capacity to retain copper. The amendment of acidic pecan shell-derived activated carbon and basic broiler litter biochar lead to a greater enhancement of copper sorption in Norfolk soil than in San Joaquin soil. In Norfolk soil, the amendment of acidic activated carbon enhanced copper sorption primarily via cation exchange mechanism, i.e., release of proton, calcium, and aluminum, while acid dissolution of aluminum cannot be ruled out. For San Joaquin soil, enhanced copper retention by biochar amendment likely resulted from the following additional mechanisms: electrostatic interactions between copper and negatively charged soil and biochar surfaces, sorption on mineral (ash) components, complexation of copper by surface functional groups and delocalized π electrons of carbonaceous materials, and precipitation. Influence of biochar on the release of additional elements (e.g., Al, Ca) must be carefully considered when used as a soil amendment to sequester heavy metals.

  4. [Study on pollution evaluation of heavy metal in surface soil of the original site of Qingdao North Station].

    PubMed

    Zhu, Lei; Jia, Yong-gang; Pan, Yu-ying

    2013-09-01

    The determination of pollution extent and health risk assessment are the premise of heavy metal contaminated site remediation. The content of Cu, Cr, Pb, Cd, Zn, Ni in Qingdao North Station was detected, and the correlation of the 6 kinds of heavy metal content was analyzed. The pollution extent in excess of background values was characterized by anthropogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geoaccumulation index and a new method which connects geoaccumulation index with Nemero index. Finally, human health risk assessment was carried out with health risk assessment model for heavy metal content. The results showed that Qingdao North Station soil were polluted by heavy metals. Six heavy metal pollution levels were: Cd > Cu > Ni > Pb > Cr > Zn, and Cd had reached the severity pollution level, Cu and Ni followed by, Cr, Pb and Zn were in minor pollution level. The order of coefficient variation in all heavy metals was: Cd > Ni > Cr > Zn > Pb > Cu. Within the study area soil heavy metal distribution was different, but overall discrepancy was small. The order of non-cancer hazards of heavy metals in soil was Cr > Pb > Cu > Ni > Cd > Zn, and the order of carcinogen risks of heavy metals was Ni > Cd. The non-cancer hazard and carcinogen risks values of metals were both lower than that their threshold values. They were not the direct threats to human health.

  5. Migration, speciation and distribution of heavy metals in an oil-polluted soil affected by crude oil extraction processes.

    PubMed

    Fu, Xiaowen; Cui, Zhaojie; Zang, Guolong

    2014-07-01

    Heavy metals are among the major pollutants in the worldwide soil environment. In oilfields, the crude oil extraction process results in the simultaneous contamination of the soil with petroleum and heavy metals. In this work, we investigated the influence of oil extraction on the migration, speciation, and temporal distribution of heavy metals (Cu, Zn, Pb, Cd, Cr, Mn, Ni, V, and Mn) in soils of an oil region of Shengli Oilfield, China. The results showed that oil-polluted soils were contaminated with Cu, Zn, Cd and Ni, with mean concentrations of 27.63, 67.12, 0.185 and 33.80 mg kg(-1), respectively (greater than the background values of local surface soils). Compared with the control profile, the vertical distributions of Cu, Zn, Pb, Cd, Ni, and V were affected in oil-polluted soils, particularly those of Cd and Ni. The concentrations of Zn, Cd, Ni, V, and Mn in oil-polluted soils increased with the duration of oil well development, which indicated the levels of these metals in the oil field were enhanced by human activities. Fractionation analysis revealed that the mobility potential of heavy metals in oil polluted soil decreased in the sequence Cd > Mn > Zn > Ni > Pb > Cu > Cr > V. The most important proportion of Cd is ion exchangeable and acid soluble, which indicates that Cd is the most labile, available, and harmful heavy metal among the elements that damage the soil environment in oil-polluted soil.

  6. Characteristics of heavy metal transfer and their influencing factors in different soil-crop systems of the industrialization region, China.

    PubMed

    Chen, Hongyan; Yuan, Xuyin; Li, Tianyuan; Hu, Sun; Ji, Junfeng; Wang, Cheng

    2016-04-01

    Soil heavy metals and their bioaccumulation in agricultural products have attracted widespread concerns, yet the transfer and accumulation characteristics of heavy metals in different soil-crop systems was rarely investigated. Soil and crop samples were collected from the typical agricultural areas in the Yangtze River Delta region, China. The concentrations of Cu, Pb, Zn, Cd and Hg in the soils, roots and grains of rice (Oryza Sativa L.), wheat (Triticum L.) and canola (Brassica napus L.) were determined in this study. Transfer ability of heavy metals in soil-rice system was stronger than those in soil-wheat and soil-canola systems. The wheat showed a strong capacity to transfer Zn, Cu and Cd from root to the grain while canola presented a restricting effect to the intake of Cu and Cd. Soil pH and total organic matter were major factors influencing metal transfer from soil to rice, whereas soil Al2O3 contents presented a negative effect on heavy metal mobility in wheat and canola cultivation systems. The concentration of Zn and Cd in crop grains could well predicted according to the stepwise multiple linear regression models, which could help to quantitatively evaluate the ecologic risk of heavy metal accumulation in crops in the study area.

  7. Use of a general toxicity test to predict heavy metal concentrations in residential soils.

    PubMed

    Aelion, C Marjorie; Davis, Harley T

    2007-03-01

    Significant clusters of developmental delay and mental retardation (DD/MR) were identified in children born in South Carolina. Although it is difficult to identify one factor that causes DD/MR, environmental insult including exposure of pregnant women to heavy metals can induce DD/MR in their children. Because it is expensive to measure the concentrations of individual metals in large numbers of environmental samples, the general Microtox toxicity test was used to identify highly toxic soil samples. Approximately 100 soil samples were collected from residential areas and analyzed to determine an effective concentration (EC(50)) of soil required to inhibit 50% light emission of the luminescent bacterial test organism (Vibrio fischeri). The EC(50) values were then transformed to relative toxicity units (RTU). A subset of 56 high and low toxicity soil samples was