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

Risk assessment of mineral and heavy metal content of selected tea products from the Ghanaian market.

PubMed

Nkansah, Marian Asantewah; Opoku, Francis; Ackumey, Abiathar Abraham

2016-06-01

Food consumption is the most likely route of human exposure to metals. Tea (Camellia sinensis L.) is among the most widely consumed non-alcoholic beverages. Concentrations of heavy metals and minerals in tea from 15 different brands in Kumasi, Ghana were measured to assess the health risk associated with their consumption. The mineral and metal contents (Fe, Cu, Zn, Pb, As, Cd) were analyzed using atomic absorption spectrophotometer (Z-8100 polarized Zeeman). The results revealed that the mean concentrations were in the order: Ca > Fe > As > Cd > Zn > Pb. The average contents of Ca, Fe, Zn, Pb, Cd, and As in the samples were 94.08, 6.15, 0.20, 0.16, 0.36, and 1.66 mg/kg, respectively. All the minerals and heavy metals were below the maximum permissible limits stipulated by the World Health Organization (WHO) and US Pharmacopeia (USP). Metal-to-metal correlation indicated strong correlations between As/Zn, Cd/Zn, Cd/As, and Pb/As pairs. Factor analysis demonstrated a clear separation between minerals, grouped on one side, and heavy metals, clustered on another side. Both the target hazard quotient (THQ) and hazard index (HI) levels in green tea were far below 1, suggesting that consumption of green tea should pose no potential risk to human health. However, carcinogenic risk levels for arsenic were high; R > 10(-6). The results showed that residents in Kumasi consume tea could be at risk from exposure to these heavy metals and minerals.

Effect of vermicomposting on calcium, sulphur and some heavy metal content of different biodegradable organic wastes under liming and microbial inoculation.

PubMed

Das, Debabrata; Bhattacharyya, Pradip; Ghosh, B C; Banik, Pabitra

2012-01-01

A study was conducted to evaluate the changes in total calcium and sulphur and some heavy metal (Zn, Cu, and Pb) concentration of different organic wastes affected by liming and microorganism inoculation. Vermicomposting was an effective technology for disposal of organic substrates like municipal solid wastes (MSW), possessing comparatively higher concentration of heavy metals. The addition of lime in initial organic substrates significantly (P ≤ 0.05) increased total calcium and total sulphur content of vermicomposts. Inoculation of microorganisms significantly (P ≤ 0.05) reduced the heavy metal content of final products as compared to control. Fungal strains were comparatively more effective in detoxification of heavy metals than B. polymyxa.

Changes in fatty acid content and composition between wild type and CsHMA3 overexpressing Camelina sativa under heavy-metal stress.

PubMed

Park, Won; Feng, Yufeng; Kim, Hyojin; Suh, Mi Chung; Ahn, Sung-Ju

2015-09-01

Under heavy-metal stress, CsHMA3 overexpressing transgenic Camelina plants displayed not only a better quality, but also a higher quantity of unsaturated fatty acids in their seeds compared with wild type. Camelina sativa L. belongs to the Brassicaceae family and is frequently used as a natural vegetable oil source, as its seeds contain a high content of fatty acids. In this study, we observed that, when subjected to heavy metals (Cd, Co, Zn and Pb), the seeds of CsHMA3 (Heavy-Metal P1B-ATPase 3) transgenic lines retained their original golden yellow color and smooth outline, unlike wild-type seeds. Furthermore, we investigated the fatty acids content and composition of wild type and CsHMA3 transgenic lines after heavy metal treatments compared to the control. The results showed higher total fatty acid amounts in seeds of CsHMA3 transgenic lines compared with those in wild-type seeds under heavy-metal stresses. In addition, the compositions of unsaturated fatty acids-especially 18:1 (oleic acid), 18:2 (linoleic acid; only in case of Co treatment), 18:3 (linolenic acid) and 20:1 (eicosenoic acid)-in CsHMA3 overexpressing transgenic lines treated with heavy metals were higher than those of wild-type seeds under the same conditions. Furthermore, reactive oxygen species (ROS) contents in wild-type leaves and roots when treated with heavy metal were higher than in CsHMA3 overexpressing transgenic lines. These results indicate that overexpression of CsHMA3 affects fatty acid composition and content-factors that are responsible for the fuel properties of biodiesel-and can alleviate ROS accumulation caused by heavy-metal stresses in Camelina. Due to these factors, we propose that CsHMA3 transgenic Camelina can be used for phytoremediation of metal-contaminated soil as well as for oil production.

[Heavy metals contents and Hg adsorption characteristics of mosses in virgin forest of Gongga Mountain].

PubMed

Liang, Peng; Yang, Yong-Kui; He, Lei; Wang, Ding-Yong

2008-06-01

Seven main moss species in the Hailuogou virgin forest of Gongga Mountain were sampled to determine their heavy metals (Hg, Cr, Cd, Ni, Pb, Cu, Mn, Zn and Fe) content, and two widely distributed species, Pleurozium schreberi (Brid.) Mitt. and Racomitrium laetum Besch., were selected to study their Hg adsorption characteristics. The results showed that the heavy metals contents in the mosses were lower than the background values in Europe and America, except that the Cd had a comparable value, which indicated that the atmosphere in study area was not polluted by heavy metals and good in quality. The Hg adsorption by P. schreberi and R. laetum was an initiative and rapid process, with the equilibrium reached in about two hours, and could be well fitted by Freundlich and Langmuir equations. Based on Langmuir equation, the maximum Hg adsorption capacities of P. schreberi and R. laetum were 15.24 and 8.19 mg x g(-1), respectively, suggesting that the two mosses had a good capacity of Hg adsorption, and could be used as the bio-monitors of atmospheric Hg pollution.

[Beijing common green tree leaves' accumulation capacity for heavy metals].

PubMed

Li, Shao-Ning; Kong, Ling-Wei; Lu, Shao-Wei; Chen, Bo; Gao, Chen; Shi, Yuan

2014-05-01

Seasonal variation of heavy metal contents in leaves and their relationships with soil heavy metal pollution levels were studied through measuring and analyzing the leaves of the common tree species in Beijing and soil heavy metal contents, to detect heavy metal accumulation ability of plant leaves. The results showed that: (1) the contents of Cu, Pb, Zn in plant leaves first decreased and then increased, again declined with changing the seasons (from spring to winter). Cr concentration showed the trend of first increase and then decrease from spring to winter, and the highest in the autumn; the accumulation capacities of Cu for Babylonica and Japonica were higher in the spring, summer and autumn, while Tabuliformis was in winter; the higher accumulation capacities for Cr, Pb were Japonica and Platycladus, and in winter were Platycladus and Bungeana; the higher accumulation capacities for Zn were Babylonica and Bungeana, while Platycladus in winter; (2) the pollution degree of four kinds of heavy metals (Cu, Cr, Pb, Zn) from downtown to suburbs showed that: Jingshan (C =2.48, C is contamination factor) > Olympic (C = 1.27) > Songshan (C = 1.20) > Shuiguan (C = 1. 18); (3) the heavy metals concentration of same plant leaves in the water of the Great Wall changed larger, but those in the other three areas showed that: Jingshan > Olympic > Songshan; the ability of same species leaf to absorb different sorts of heavy metals showed that: Zn >Cu >Pb >Cr; the difference between Zn content and Cr content was significant (P <0.01); (4) the relationship between heavy metal content in plant leaves and soil heavy metal pollution levels presented a quadratic polynomial relation; the significant correlation was found between other three heavy metal contents of plant samples and soil samples, but they were not the case for the Cu, and the correlation coefficients were above 0. 9.

Stabilization of heavy metals in sludge ceramsite.

PubMed

Xu, G R; Zou, J L; Li, G B

2010-05-01

This paper attempts to investigate the stabilization behaviours of heavy metals in ceramsite made from wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS). Leaching tests were conducted to find out the effects of sintering temperature, (Fe(2)O(3) + CaO + MgO)/(SiO(2) + Al(2)O(3)) (defined as F/SA ratios), pH, and oxidative condition. Results show that sintering exhibits good binding capacity for Cd, Cr, Cu, and Pb in ceramsite and leaching contents of heavy metals will not change above 1000 degrees C. The main crystalline phases in ceramsite sintered at 1000 degrees C are kyanite, quartz, Na-Ca feldspars, sillimanite, and enstatite. The main compounds of heavy metals are crocoite, chrome oxide, cadmium silicate, and copper oxide. Leaching contents of Cd, Cu, and Pb increase as the F/SA ratios increase. Heavy metals in ceramsite with variation of F/SA ratios are also in same steady forms, which prove that stronger chemical bonds are formed between these heavy metals and the components. Leaching contents of heavy metals decrease as pH increases and increase as H(2)O(2) concentration increases. The results indicate that when subjected to rigorous leaching conditions, the crystalline structures still exhibit good chemical binding capacity for heavy metals. In conclusion, it is environmentally safe to use ceramsite in civil and construction fields. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Heavy metals content in acid mine drainage at abandoned and active mining area

NASA Astrophysics Data System (ADS)

Hatar, Hazirah; Rahim, Sahibin Abd; Razi, Wan Mohd; Sahrani, Fathul Karim

2013-11-01

This study was conducted at former Barite Mine, Tasik Chini and former iron mine Sungai Lembing in Pahang, and also active gold mine at Lubuk Mandi, Terengganu. This study was conducted to determine heavy metals content in acid mine drainage (AMD) at the study areas. Fourteen water sampling stations within the study area were chosen for this purpose. In situ water characteristic determinations were carried out for pH, electrical conductivity (EC), redox potential (ORP) and total dissolved solid (TDS) using multi parameter YSI 556. Water samples were collected and analysed in the laboratory for sulfate, total acidity and heavy metals which follow the standard methods of APHA (1999) and HACH (2003). Heavy metals in the water samples were determined directly using Inductive Coupled Plasma Mass Spectrometry (ICP-MS). Data obtained showed a highly acidic mean of pH values with pH ranged from 2.6 ± 0.3 to 3.2 ± 0.2. Mean of electrical conductivity ranged from 0.57 ± 0.25 to 1.01 ± 0.70 mS/cm. Redox potential mean ranged from 487.40 ± 13.68 to 579.9 ± 80.46 mV. Mean of total dissolved solids (TDS) in AMD ranged from 306.50 ± 125.16 to 608.14 ± 411.64 mg/L. Mean of sulfate concentration in AMD ranged from 32.33 ± 1.41 to 207.08 ± 85.06 mg/L, whereas the mean of total acidity ranged from 69.17 ± 5.89 to 205.12 ± 170.83 mgCaCO3/L. Heavy metals content in AMD is dominated by Fe, Cu, Mn and Zn with mean concentrations range from 2.16 ± 1.61 to 36.31 ± 41.02 mg/L, 0.17 ± 0.13 to 11.06 ± 2.85 mg/L, 1.12 ± 0.65 to 7.17 ± 6.05 mg/L and 0.62 ± 0.21 to 6.56 ± 4.11 mg/L, respectively. Mean concentrations of Ni, Co, As, Cd and Pb were less than 0.21, 0.51, 0.24, 0.05 and 0.45 mg/L, respectively. Significant correlation occurred between Fe and Mn, Cu, Zn, Co and Cd. Water pH correlated negatively with all the heavy metals, whereas total acidity, sulfate, total dissolved solid, and redox potential correlated positively. The concentration of heavy metals in the AMD

Enhancing the use of waste activated sludge as bio-fuel through selectively reducing its heavy metal content.

PubMed

Dewil, Raf; Baeyens, Jan; Appels, Lise

2007-06-18

Power plant or cement kiln co-incineration are important disposal routes for the large amounts of waste activated sludge (WAS) which are generated annually. The presence of significant amounts of heavy metals in the sludge however poses serious problems since they are partly emitted with the flue gases (and collected in the flue gas dedusting) and partly incorporated in the ashes of the incinerator: in both cases, the disposal or reuse of the fly ash and bottom ashes can be jeopardized since subsequent leaching in landfill disposal can occur, or their "pozzolanic" incorporation in cement cannot be applied. The present paper studies some physicochemical methods for reducing the heavy metal content of WAS. The used techniques include acid and alkaline thermal hydrolysis and Fenton's peroxidation. By degrading the extracellular polymeric substances, binding sites for a large amount of heavy metals, the latter are released into the sludge water. The behaviour of several heavy metals (Cd, Cr, Cu, Hg, Pb, Ni, Zn) was assessed in laboratory tests. Results of these show a significant reduction of most heavy metals.

Wide-scale utilization of MSWI fly ashes in cement production and its impact on average heavy metal contents in cements: The case of Austria.

PubMed

Lederer, Jakob; Trinkel, Verena; Fellner, Johann

2017-02-01

A number of studies present the utilization of fly ashes from municipal solid waste incineration (MSWI) in cement production as a recycling alternative to landfilling. While there is a lot of research on the impact of MSWI fly ashes utilization in cement production on the quality of concrete or the leaching of heavy metals, only a few studies have determined the resulting heavy metal content in cements caused by this MSWI fly ashes utilization. Making use of the case of Austria, this study (1) determines the total content of selected heavy metals in cements currently produced in the country, (2) designs a scenario and calculates the resulting heavy metal contents in cements assuming that all MSWI fly ashes from Austrian grate incinerators were used as secondary raw materials for Portland cement clinker production and (3) evaluates the legal recyclability of demolished concretes produced from MSWI fly ash amended cements based on their total heavy metal contents. To do so, data from literature and statistics are combined in a material flow analysis model to calculate the average total contents of heavy metals in cements and in the resulting concretes according to the above scenario. The resulting heavy metal contents are then compared (i) to their respective limit values for cements as defined in a new technical guideline in Austria (BMLFUW, 2016), and (ii) to their respective limit values for recycling materials from demolished concrete. Results show that MSWI fly ashes utilization increases the raw material input in cement production by only +0.9%, but the total contents of Cd by +310%, and Hg, Pb, and Zn by +70% to +170%. However these and other heavy metal contents are still below their respective limit values for Austrian cements. The same legal conformity counts for recycling material derived from concretes produced from the MSWI fly ash cements. However, if the MSWI fly ash ratio in all raw materials used for cement production were increased from 0.9% to 22

Heavy metal content (Cd, Ni, Cr and Pb) in soil amendment with a low polluted biosolid

NASA Astrophysics Data System (ADS)

Gomez Lucas, Ignacio; Lag Brotons, Alfonso; Navarro-Pedreño, Jose; Belén Almendro-Candel, Maria; Jordán, Manuel M.; Bech, Jaume; Roca, Nuria

2016-04-01

The progressively higher water quality standards in Europe has led to the generation of large quantities of sewage sludge derived from wastewater treatment (Fytili and Zabaniotou 2008). Composting is an effective method to minimize these risks, as pathogens are biodegraded and heavy metals are stabilized as a result of organic matter transformations (Barker and Bryson 2002; Noble and Roberts 2004). Most of the studies about sewage sludge pollution are centred in medium and high polluted wastes. However, the aim of this study was to assess the effects on soil heavy metal content of a low polluted sewage sludge compost in order to identify an optimal application rate based in heavy metal concentration under a period of cultivation of a Mediterranean horticultural plant (Cynara carducnculus). The experiment was done between January to June: rainfall was 71 mm, the volume of water supplied every week was 10.5 mm, mean air temperatures was 14.2, 20.4 (maximum), and 9.2◦C (minimum). The soil was a clay-loam anthrosol (WRB 2006). The experimental plot (60 m2) was divided into five subplots with five treatments corresponding to 0, 2, 4, 6, and 8 kg compost/m2. Three top-soil (first 20 cm) samples from each treatment were taken (January, April and June) and these parameters were analysed: pH, electrical conductivity, organic matter and total content of heavy metals (microwave acid digestion followed by AAS-spectrometry determination). The results show that sewage sludge compost treatments increase the organic matter content and salinity (electrical conductivity of the soils) and diminish the pH. Cd and Ni total content in top-soil was affected and both slightly reduce their concentration. Pb and Cr show minor changes. In general, the application of this low polluted compost may affect the mobility of Cd and Ni due to the pH modification and the water added by irrigation along time but Pb and Cr remain their content in the top-soil. References Barker, A.V., and G.M. Bryson

Red cabbage yield, heavy metal content, water use and soil chemical characteristics under wastewater irrigation.

PubMed

Tunc, Talip; Sahin, Ustun

2016-04-01

The objective of this 2-year field study was to evaluate the effects of drip irrigation with urban wastewaters reclaimed using primary (filtration) and secondary (filtration and aeration) processes on red cabbage growth and fresh yield, heavy metal content, water use and efficiency and soil chemical properties. Filtered wastewater (WW1), filtered and aerated wastewater (WW2), freshwater and filtered wastewater mix (1:1 by volume) (WW3) and freshwater (FW) were investigated as irrigation water treatments. Crop evapotranspiration decreased significantly, while water use efficiency increased under wastewater treatments compared to FW. WW1 treatment had the lowest value (474.2 mm), while FW treatments had the highest value (556.7 mm). The highest water use efficiency was found in the WW1 treatment as 8.41 kg m(-3), and there was a twofold increase with regard to the FW. Wastewater irrigation increased soil fertility and therefore red cabbage yield. WW2 treatment produced the highest total fresh yield (40.02 Mg ha(-1)). However, wastewater irrigation increased the heavy metal content in crops and soil. Cd content in red cabbage heads was above the safe limit, and WW1 treatment had the highest value (0.168 mg kg(-1)). WW3 treatment among wastewater treatments is less risky in terms of soil and crop heavy metal pollution and faecal coliform contamination. Therefore, WW3 wastewater irrigation for red cabbage could be recommended for higher yield and water efficiency with regard to freshwater irrigation.

Heavy metal concentrations in bovine tissues (muscle, liver and kidney) and their relationship with heavy metal contents in consumed feed.

PubMed

Hashemi, Majid

2018-06-15

Toxic (lead, cadmium and mercury) and essential trace (copper and zinc) metals were measured in muscle, liver and kidney samples of bovine and their relationships with heavy metal concentrations in consumed feed were studied. A total of 216 tissue samples from 72 cows and 216 feed samples from 18 farms were collected during four seasons and analyzed for heavy metals by inductively coupled plasma-optical emission spectrometry after wet digestion. The arithmetic mean concentrations (mg/Kg wet weight) of lead (Pb), cadmium (Cd) and mercury were respectively, 0.221, 0.028 and 0.003 in muscle, 0.273, 0.047 and 0.002 in liver and 0.244, 0.114 and 0.003 in kidney. All measured concentrations (with the exception of Pb in muscle) were below the European Union maximum residual limits (MRL). The Cd contents of the kidney were significantly higher than which observed in other tissues. Although, copper (Cu) and zinc (Zn) levels in all of samples were below MRL, but results showed that many cattles may be suffering from Cu and/or Zn deficiency. Significant and positive correlations between Pb (p < 0.05, r = 0.163) and Cd (p < 0.01, r = 0.303) concentrations in feed and studied organs were observed. As a considerable amount of metals above MRL were noticed in our study, continuous monitoring of these metals is recommended to avoid hazardous transfer to human through the food of animal origin. Copyright © 2018 Elsevier Inc. All rights reserved.

The impact of sewage sludge treatment on the content of selected heavy metals and their fractions.

PubMed

Ignatowicz, Katarzyna

2017-07-01

The aim of the study was to assess the physicochemical properties of compost made of municipal sewage sludge from selected Municipal Sewage Treatment Plant. Content of basic macroelements and heavy metals (Zn, Cu, Cr, Cd, Ni, Pb, Hg, Mg, Ca, N, P, K, Na) and their fractions was determined by means of BCR method. Based on the analyzes, it was found that the content of heavy metals in compost did not exceed the limits set by natural land management of sewage sludge; the compost is very abundant in biogenic elements - nitrogen and phosphorus - and it can be also considered a significant source of calcium and magnesium. The analysis of results obtained from the three-stage chemical extraction revealed that deposits subjected to aerobic stabilization and composting accumulate metals (in descending sequence) in fractions III and II, i.e. fractions virtually inaccessible to the ecosystem in optimal conditions of use. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Content of Heavy Metal in the Dust of Leisure Squares and Its Health Risk Assessment-A Case Study of Yanta District in Xi'an.

PubMed

Shao, Tianjie; Pan, Lihuan; Chen, Zhiqing; Wang, Ruiyuan; Li, Wenjing; Qin, Qing; He, Yuran

2018-02-25

Taking Yanta District in Xi'an as the research object, the present study measures the contents of Cadmium (Cd), Lead (Pb), Copper (Cu), Nickel (Ni), and Chromium (Cr) in dust samples and further assesses the health risk of heavy metals intake through dust based on the assessment method of human exposure risk proposed by U.S. EPA, with an aim to investigate the content of heavy metal in the dust of leisure squares and its exposure risk. As the results indicate, the average contents of five heavy metals are obviously higher than the soil background value in Shaanxi Province. Therefore, Cd, Ni, Cu, Pb, and Cr are obviously enriched in urban surface dust in Shaanxi Province, due to the influence of human activities. In addition, it can also be found that the non-carcinogen exposure risk in children is significantly higher than that in adults with the risk values of these five heavy metals all one order of magnitude higher than those of adults. Irrespective of whether addressing the results for children or adults, the non-carcinogen exposure doses of five heavy metals are sorted as Cr > Pb > Cu > Ni > Cd. According to the present situation, for a child, the total non-carcinogenic risk values of five heavy metals have exceeded the safety limit in 11 of the 20 leisure squares in Yanta District of Xi'an. That means the leisure squares are no longer suitable for physical and recreational activities. For the five heavy metals, the average non-carcinogenic risk value of Cr is largest, and causes the largest threat to health in Yanta District, Xi'an. The carcinogenic exposure doses of the heavy metals Cr, Cd, and Ni are very low in respiratory pathways and there is no carcinogenic health risk. In general, the Cr content in dust in domestic cities is higher than that of foreign cities; however, the Pb content is much lower.

[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

Functional Expression of a Bacterial Heavy Metal Transporter in Arabidopsis Enhances Resistance to and Decreases Uptake of Heavy Metals1[w

PubMed Central

Lee, Joohyun; Bae, Hyunju; Jeong, Jeeyon; Lee, Jae-Yun; Yang, Young-Yell; Hwang, Inhwan; Martinoia, Enrico; Lee, Youngsook

2003-01-01

Large parts of agricultural soil are contaminated with lead (Pb) and cadmium (Cd). Although most environments are not heavily contaminated, the low levels observed nonetheless pose a high risk of heavy metal accumulation in the food chain. Therefore, approaches to develop plants with reduced heavy metal uptake are important. Recently, many transgenic plants with increased heavy metal resistance and uptake of heavy metals were developed for the purpose of phytoremediation. However, to reduce heavy metal in the food chain, plants that transfer less heavy metals to the shoot are required. We tested whether an Escherichia coli gene, ZntA, which encodes a Pb(II)/Cd(II)/Zn(II) pump, could be useful for developing plants with reduced heavy metal content. Yeast cells transformed with this gene had improved resistance to Pb(II) and Cd(II). In Arabidopsis plants transformed with ZntA, ZntA was localized at the plasma membrane and improved the resistance of the plants to Pb(II) and Cd(II). The shoots of the transgenic plants had decreased Pb and Cd content. Moreover, the transgenic protoplasts showed lower accumulation of Cd and faster release of preloaded Cd than wild-type protoplasts. These results show that a bacterial transporter gene, ZntA, can be functionally expressed in plant cells, and that that it may be useful for the development of crop plants that are safe from heavy metal contamination. PMID:14512517

Contents of heavy metals in urban parks and university campuses

NASA Astrophysics Data System (ADS)

Zhang, Yong; Chen, Qian

2018-01-01

Because the city park has become an important place for people's daily leisure, and the university campus is one of the most densely populated areas of the city, their environmental pollution is critical for the health and safety of the residents. In this paper, two kinds of evaluation methods were used to evaluate the content of Cu, Zn, As and Pb in soils of city parks and university campus in Xiangtan. The results showed that only Juhuatang Park was a non-polluted area, and the other 7 sampling sites were lightly polluted; Analysis shows the heavy metal contents of soil in city parks are closely related to vehicle emissions, agriculture and irrigation, combustion of household waste, living area and commercial shops, the use of fossil fuels, industrial waste gas and waste residue and other human activities.

Feasibility analysis of EDXRF method to detect heavy metal pollution in ecological environment

NASA Astrophysics Data System (ADS)

Hao, Zhixu; Qin, Xulei

2018-02-01

The change of heavy metal content in water environment, soil and plant can reflect the change of heavy metal pollution in ecological environment, and it is important to monitor the trend of heavy metal pollution in eco-environment by using water environment, soil and heavy metal content in plant. However, the content of heavy metals in nature is very low, the background elements of water environment, soil and plant samples are complex, and there are many interfering factors in the EDXRF system that will affect the spectral analysis results and reduce the detection accuracy. Through the contrastive analysis of several heavy metal elements detection methods, it is concluded that the EDXRF method is superior to other chemical methods in testing accuracy and method feasibility when the heavy metal pollution in soil is tested in ecological environment.

Proximate Composition, Amino Acid, Mineral, and Heavy Metal Content of Dried Laver

PubMed Central

Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

2013-01-01

Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and γ-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals. PMID:24471123

Proximate composition, amino Acid, mineral, and heavy metal content of dried laver.

PubMed

Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

2013-06-01

Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and γ-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals.

The effect of low-temperature transformation of mixtures of sewage sludge and plant materials on content, leachability and toxicity of heavy metals.

PubMed

Gondek, Krzysztof; Baran, Agnieszka; Kopeć, Michał

2014-12-01

The aim of the study was to determine the influence of the process of low-temperature transformation and the addition of plant material to sewage sludge diversifying the content of mobile forms of heavy metals and their ecotoxicity. The experimental design included: sewage sludge+rape straw, sewage sludge+wheat straw, sewage sludge+sawdust, sewage sludge+bark and sewage sludge with no addition. The mixtures were subjected to thermal transformation in a chamber furnace, under conditions without air. The procedure consisted of two stages: the first stage (130°C for 40 min) focused on drying the material, whereas in the second stage (200°C for 30 min) proper thermal transformation of materials took place. Thermal transformation of the materials, caused an increase in total contents of heavy metals in comparison to the material before transformation. From among elements, the cadmium content changed the most in materials after thermal transformation. As a result of thermal transformation, the content of water soluble form of the heavy metals decreased significantly in all the prepared mixtures. Low toxicity of the extracts from materials for Vibrio fischeri and Lepidium sativum was found in the research, regardless of transformation process. L. sativum showed higher sensitivity to heavy metals occurring in the studied extracts from materials than V. fischeri, evidence of which are the positive significant correlations between the content of metals and the inhibition of root growth of L. sativum. Copyright © 2014 Elsevier Ltd. All rights reserved.

Heavy Metal Contents and Physical Parameters of Aegiceras corniculatum, Brassica juncea, and Litchi chinensis Honeys from Bangladesh

PubMed Central

Sarker, Nandita; Chowdhury, Muhammed Alamgir Zaman; Fakhruddin, Abu Naieum Muhammad; Fardous, Zeenath; Moniruzzaman, Mohammed; Gan, Siew Hua

2015-01-01

The present study was undertaken to determine the heavy metal levels and the physicochemical parameters (pH, electrical conductivity (EC), and ash, moisture, and total sugar content) of honeys from Bangladesh. Three different floral honeys were investigated, namely, khalsi (Aegiceras corniculatum), mustard (Brassica juncea), and litchi (Litchi chinensis) honeys. The heavy metals in the honeys were determined by using a High Temperature Dry Oxidation method followed by Atomic Absorption Spectroscopy. The mean pH, EC, and ash, moisture, and total sugar contents of the investigated honeys were 3.6, 0.51 mS/cm, 0.18%, 18.83%, and 68.30%, respectively. Iron was the most abundant among all the investigated heavy metals, ranging from 13.51 to 15.44 mg/kg. The mean concentrations of Mn and Zn in the investigated honeys were 0.28 mg/kg and 2.99 mg/kg, respectively. Cd was below the detection limit, and lead was found in some honey samples, but their contents were below the recommended Maximum Acceptable Level. Cr was also found in all of the samples, but its concentration was within the limit. The physicochemical analysis of the honey samples yielded levels within the limits set by the international honey legislation, indicating that the honey samples were of good quality and had acceptable values for maturity, purity, and freshness. PMID:26618176

Heavy Metal Contents and Physical Parameters of Aegiceras corniculatum, Brassica juncea, and Litchi chinensis Honeys from Bangladesh.

PubMed

Sarker, Nandita; Chowdhury, Muhammed Alamgir Zaman; Fakhruddin, Abu Naieum Muhammad; Fardous, Zeenath; Moniruzzaman, Mohammed; Gan, Siew Hua

2015-01-01

The present study was undertaken to determine the heavy metal levels and the physicochemical parameters (pH, electrical conductivity (EC), and ash, moisture, and total sugar content) of honeys from Bangladesh. Three different floral honeys were investigated, namely, khalsi (Aegiceras corniculatum), mustard (Brassica juncea), and litchi (Litchi chinensis) honeys. The heavy metals in the honeys were determined by using a High Temperature Dry Oxidation method followed by Atomic Absorption Spectroscopy. The mean pH, EC, and ash, moisture, and total sugar contents of the investigated honeys were 3.6, 0.51 mS/cm, 0.18%, 18.83%, and 68.30%, respectively. Iron was the most abundant among all the investigated heavy metals, ranging from 13.51 to 15.44 mg/kg. The mean concentrations of Mn and Zn in the investigated honeys were 0.28 mg/kg and 2.99 mg/kg, respectively. Cd was below the detection limit, and lead was found in some honey samples, but their contents were below the recommended Maximum Acceptable Level. Cr was also found in all of the samples, but its concentration was within the limit. The physicochemical analysis of the honey samples yielded levels within the limits set by the international honey legislation, indicating that the honey samples were of good quality and had acceptable values for maturity, purity, and freshness.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China.

PubMed

Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

2018-02-22

Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation ( p < 0.05) between traffic volume and concentration for three heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation ( p < 0.05) was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution.

Monitoring Heavy Metal Contents with Sphagnum Junghuhnianum Moss Bags in Relation to Traffic Volume in Wuxi, China

PubMed Central

Hu, Rong; Yan, Yun; Zhou, Xiaoli; Wang, Yanan; Fang, Yanming

2018-01-01

Despite its small size, a moss bag can reveal the different temporal and spatial deposition patterns of pollutants at a particular site; therefore, researchers can use moss bags to determine pollution sources and to put forward strategies for pollution control. Although the use of moss bags to monitor atmospheric pollution has been widely reported in Europe, there are few such empirical studies in China. Thus, in this study, bags containing the moss Sphagnum junghuhnianum were used to assess the concentrations of heavy metals (chromium (Cr), copper (Cu), lead (Pb), vanadium (V), and zinc (Zn)) at five sampling sites (four roads and a forest park) during the summer and winter of 2012. According to the relative accumulation factor (RAF) and contamination factor (CF) results, pollution in winter was heavier than that in summer, and Cr was found to be the most contaminating, having the highest mean CF. There was a significant positive correlation (p < 0.05) between traffic volume and concentration for three heavy metals (Cr, Cu, and V) in winter, whereas a significant positive correlation (p < 0.05) was observed between traffic volume and concentrations for four heavy metal elements (Cr, Pb, V, and Zn) in summer, indicating a close relationship between heavy metal contents and traffic volume. Although there was substantial variation in the concentrations of the five heavy metals in the moss bags, significant correlations between heavy metals suggested that the contaminants originated from a common source, namely vehicle emissions. The results demonstrated that the four roads were subject to different degrees of pollution depending on the volume of traffic using each road. Therefore, the results of this study suggest that traffic volume is a major reason for heavy metal pollution. PMID:29470433

Mineral and heavy metal contents of the outer and inner tissues of commonly used fruits.

PubMed

Özcan, Mehmet Musa; Harmankaya, Mustafa; Gezgin, Sait

2012-01-01

The rate of heavy metal pollution in some minor fruit samples growing at roadsides in Turkey were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The mineral contents of samples were found to be different depending on the several parts Citrus fruits. The highest minor and heavy metal levels for Citrus fruits were determined between 17.24 and 45.30 mg/kg boron, 2.08 and 15.05 mg/kg copper, 1.01 and 16.00 mg/kg iron and 2.35 and 9.87 mg/kg zinc. Boron content ranged from 16.54 mg/kg (Deveci pear inner pulp) to 89.89 mg/kg (Arjantin apple outer skin). The level of Fe ranged from 1.49 mg/kg (quince pulp) to 25.05 mg/kg (Ankara pear pulp). Cu content of fruits ranged between 2.52 mg/kg (Fuji apple skin) and 25.93 mg/kg quince skin). Zn content was found between 0.46 mg/kg (Golden apple pulp) and 14.34 mg/kg (quince skin). P contents ranged from 651 mg/kg (Golden apple pulp) to 1269 mg/kg (quince skin). Na was found between 500 mg/kg (Fuji apple skin) and 907 mg/kg (Arjantin apple skin).

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

PubMed

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

2017-08-21

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

Black water sludge reuse in agriculture: are heavy metals a problem?

PubMed

Tervahauta, Taina; Rani, Sonia; Hernández Leal, Lucía; Buisman, Cees J N; Zeeman, Grietje

2014-06-15

Heavy metal content of sewage sludge is currently the most significant factor limiting its reuse in agriculture within the European Union. In the Netherlands most of the produced sewage sludge is incinerated, mineralizing the organic carbon into the atmosphere rather than returning it back to the soil. Source-separation of black water (toilet water) excludes external heavy metal inputs, such as industrial effluents and surface run-offs, producing sludge with reduced heavy metal content that is a more favorable source for resource recovery. The results presented in this paper show that feces is the main contributor to the heavy metal loading of vacuum collected black water (52-84%), while in sewage the contribution of feces is less than 10%. To distinguish black water from sewage in the sludge reuse regulation, a control parameter should be implemented, such as the Hg and Pb content that is significantly higher in sewage sludge compared to black water sludge (from 50- to 200-fold). The heavy metals in feces and urine are primarily from dietary sources, and promotion of the soil application of black water sludge over livestock manure and artificial fertilizers could further reduce the heavy metal content in the soil/food cycle. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed

Li, Jianxin; Chen, Jinbo; Chen, Shan

2018-08-15

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

Multiple factors impact the contents of heavy metals in vegetables in high natural background area of China.

PubMed

Gan, Yandong; Wang, Lihong; Yang, Guiqiang; Dai, Jiulan; Wang, Renqing; Wang, Wenxing

2017-10-01

A field survey was conducted to investigate the concentrations of chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in vegetables, corresponding cultivated soils and irrigation waters from 36 open sites in high natural background area of Wuzhou, South China. Redundancy analysis, Spearman's rho correlation analysis and multiple regression analysis were adopted to evaluate the contributions of impacting factors on metal contents in the edible parts of vegetables. This study concluded that leafy and root vegetables had relatively higher metal concentrations and adjusted transfer factor values compared to fruiting vegetables according to nonparametric tests. Plant species, total soil metal content and soil pH value were affirmed as three critical factors with the highest contribution rate among all the influencing factors. The bivariate curve equation models for heavy metals in the edible vegetable tissues were well fitted to predict the metal concentrations in vegetables. The results from this case study also suggested that it could be one of efficient strategies for clean agricultural production and food safety in high natural background area to breed vegetable varieties with low heavy metal accumulation and to enlarge planting scale of these varieties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review: Nutritional ecology of heavy metals.

PubMed

Hejna, M; Gottardo, D; Baldi, A; Dell'Orto, V; Cheli, F; Zaninelli, M; Rossi, L

2018-01-08

The aim of this review is to focus the attention on the nutrition ecology of the heavy metals and on the major criticisms related to the heavy metals content in animal feeds, manure, soil and animal-origin products. Heavy metals are metallic elements that have a high density that have progressively accumulated in the food chain with negative effects for human health. Some metals are essential (Fe, I, Co, Zn, Cu, Mn, Mo, Se) to maintain various physiological functions and are usually added as nutritional additives in animal feed. Other metals (As, Cd, F, Pb, Hg) have no established biological functions and are considered as contaminants/undesirable substances. The European Union adopted several measures in order to control their presence in the environment, as a result of human activities such as: farming, industry or food processing and storage contamination. The control of the animal input could be an effective strategy to reduce human health risks related to the consumption of animal-origin products and the environmental pollution by manure. Different management of raw materials and feed, animal species as well as different legal limits can influence the spread of heavy metals. To set up effective strategies against heavy metals the complex interrelationships in rural processes, the widely variability of farming practices, the soil and climatic conditions must be considered. Innovative and sustainable approaches have discussed for the heavy metal nutrition ecology to control the environmental pollution from livestock-related activities.

Effects of heavy metals on soil microbial community

NASA Astrophysics Data System (ADS)

Chu, Dian

2018-02-01

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

Assessment of heavy metals in loose deposits in drinking water distribution system.

PubMed

Liu, Quanli; Han, Weiqiang; Han, Bingjun; Shu, Min; Shi, Baoyou

2018-06-09

Heavy metal accumulation and potential releases from loose deposits in drinking water distribution system (DWDS) can have critical impacts on drinking water safety, but the associated risks have not been sufficiently evaluated. In this work, the potential biological toxicity of heavy metals in loose deposits was calculated based on consensus-based sediment quality guidelines, and the effects of some of the main water quality parameters, such as the pH and bicarbonate and phosphate content, on the release behaviors of pre-accumulated heavy metals were investigated. The results showed that heavy metals (Cu, As, Cr, Pb, and Cd) significantly accumulated in all the samples, but the contents of the heavy metals were multiple magnitudes lower than the Fe and Mn contents. The potential biotoxicity of As and Cu was relatively high, but the biotoxicity of Cd was negligible. The water quality can significantly influence the release of heavy metals from loose deposits. As the pH increased from 7.0 to 9.0, the release of As and Cr obviously increased. The release of As, Cu, Pb, and Cr also accelerated with the addition of phosphate (from 1 to 5 mg/L). In contrast to the trends for the pH and phosphate, variations in the bicarbonate content did not have a significant influence on the release of As and Cr. The release ratios of heavy metals in the samples were very low, and there was not a correlation between the release rate of the heavy metals in the loose deposits and their potential biotoxicity.

Divergent biology of facultative heavy metal plants.

PubMed

Bothe, Hermann; Słomka, Aneta

2017-12-01

literature favours the idea that hyperaccumulation of heavy metals serves plants as deterrent against attack by feeding animals (termed elemental defense hypothesis). The capability to hyperaccumulate heavy metals in A. halleri and N. caerulescens is achieved by duplications and alterations of the cis-regulatory properties of genes coding for heavy metal transporting/excreting proteins. Several metallophytes have developed ecotypes with a varying content of such heavy metal transporters as an adaption to the specific toxicity of a heavy metal site. Copyright © 2017 Elsevier GmbH. All rights reserved.

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

Impact of highway traffic and the acoustic screen on the content and spatial distribution of heavy metals in soils.

PubMed

Różański, Szymon; Jaworska, Hanna; Matuszczak, Katarzyna; Nowak, Joanna; Hardy, Amber

2017-05-01

Recent years have witnessed intensification of road traffic and, with it, the amount of substances emitted by vehicles. Such emissions need to be monitored for public health purposes. The aim of this study was to evaluate the impact of the highway traffic on the total content and bioavailability of Zn, Cu, Ni, Cd, Cr and Pb in nearby soils as well as influence of an acoustic screen on spatial distribution of the metals. The material included 40 soil samples collected from 15 research points located 5, 10, 25 and 50 m away from the road acoustic screen and from 4 points between the screen and the highway. Additionally, 5 research points were located next to the metal barrier. Selected physicochemical properties of soils were determined: soil texture, soil pH, TOC and CaCO 3 content. The total content of heavy metals in the soils was determined by AAS after digestion in aqua regia and bioavailable forms in 1 M diethylenetriaminepentaacetic acid. The research found low impact of the highway traffic on the content of heavy metals in soils; however, due to a very short period of this potential impact (5 years), the moderately polluted category of geo-accumulation index of cadmium and high bioavailability of lead indicate the need of repeating the research within the next several years. Furthermore, the road acoustic screen significantly influenced spatial distribution of the metals in soils.

Heavy metals in hair of residents in an e-waste recycling area, south China: contents and assessment of bodily state.

PubMed

Zheng, Jing; Luo, Xiao-Jun; Yuan, Jian-Gang; He, Luo-Yiyi; Zhou, Yi-Hui; Luo, Yong; Chen, She-Jun; Mai, Bi-Xian; Yang, Zhong-Yi

2011-11-01

Heavy metals were measured in hair from occupationally and nonoccupationally exposed populations in an e-waste recycling area and from residents from a control rural town. The levels of five heavy metals were in the following order of Zn > Pb, Cu > Cd > Ni, with the highest levels found in the occupationally exposed workers. The levels of Cd, Pb, and Cu were significantly higher in residents from the e-waste recycling area than in the control area. Elevated Cd, Pb, and Cu contents along with significant positive correlations between them in hair from the e-waste recycling area indicated that these metals were likely to have originated from the e-waste recycling activities. The similarity in heavy metal pattern between children and occupationally exposed workers indicated that children are particularly vulnerable to heavy metal pollution caused by e-waste recycling activities. The increased Cu exposure might be a benefit for the insufficient intake of Cu in the studied area. However, the elevated hair Cd and Pb levels implied that the residents in the e-waste area might be at high risk of toxic metal, especially for children and occupationally exposed workers.

One-century sedimentary record of heavy metal pollution in western Taihu Lake, China.

PubMed

Li, Yan; Zhou, Shenglu; Zhu, Qing; Li, Baojie; Wang, Junxiao; Wang, Chunhui; Chen, Lian; Wu, Shaohua

2018-05-16

Long-term trends of sediment compositions are important for assessing the impact of human activities on the sediment and protecting the sediment environment. In this study, based on the contents of heavy metals and the Pb isotope ratios in lake sediments, atmospheric dustfall and soil in Yixing, China, the representative heavy metals (Zn, Pb, Cr and Cd) in lake sediments from western Taihu Lake were studied. The evolution history of heavy metals in the local environment was constructed for the past 100 years. From 1892 to the 1990s, the anthropogenic fluxes of the representative heavy metals were negligible, indicating minimal anthropogenic emissions of heavy metals. Since the 1990s, anthropogenic fluxes of the representative heavy metals began to increase, concurrent with the economic growth and development in the western Taihu Lake Basin after the Chinese economic reform. The maximum flux percentage of the heavy metals in the sediments, caused by human activities, is 23.0% for Zn, 31.6% for Pb, 39.5% for Cr and 85.3% for Cd, indicating that most of the Cd comes from human activities. The Cd content in the western Taihu Lake Basin was significantly higher than that in the other areas, and the rapid development of the industry in the western Taihu Lake Basin and ceramics in Yixing led to the enrichment of heavy metals in local sediments. Since the 21st century, measures have been taken to control the pollution of heavy metals, including the increase in local government attention and the deployment of environmental monitoring technology. However, heavy metal content remains high, and the Pb content is still increasing. The ratios of Pb isotopes show that the main sources of heavy metals in the western Taihu Lake sediments, the local soil of Yixing and the atmospheric dustfall are coal combustion, leaded gasoline combustion, industrial wastewater and domestic sewage. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Relationship between Bulk and Mobile Forms of Heavy Metals in Soils of Kursk

NASA Astrophysics Data System (ADS)

Nevedrov, N. P.; Protsenko, E. P.; Glebova, I. V.

2018-01-01

The contamination of Kursk urboecotopes by heavy metals (Pb, Cd, Zn, Cu, Ni) is considered. The relationships between the contents of bulk and mobile forms of heavy metal ions have been examined. The results of monitoring studies attest to a tendency for the accumulation of both bulk and mobile forms of heavy metals in the humus-accumulative horizon, except for bulk cadmium and mobile nickel. Linear and nonlinear regression models of the bulk contents of Pb, Cd, Zn, and Ni as dependent on the contents of their mobile forms have been developed. These models allow us to calculate the bulk content of heavy metal ions in the soils of urboecotopes using simpler methods of the extraction and laboratory determination of their mobile forms.

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

[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.

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

PubMed Central

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

2007-01-01

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

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

PubMed

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

2007-01-01

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

Heavy metal contents and transfer capacities of Phragmites australis and Suaeda salsa in the Yellow River Delta, China

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Bai, Junhong; Wang, Wei; Huang, Laibing; Zhang, Guangliang; Wang, Dawei

2018-04-01

Plant samples including roots, stems and leaves of Phragmites australis and Suaeda salsa were collected in the short-term flooding and tidal flooding wetlands of the Yellow River Delta of China. Six heavy metals (e.g., As, Cd, Cr, Cu, Pb, and Zn) were measured in roots, stems and leaves of each plant species using inductively coupled plasma atomic absorption spectrometry (ICP-AAS) to investigate the levels, and transfer capabilities of heavy metals in these two plant species. Our results showed that in the tidal flooding wetlands, the contents of As, Cr and Cd in roots of Phragmites australis and Suaeda salsa were higher than those in their stems and leaves. Suaeda salsa showed higher contents of Pb and Zn in leaves than those in roots and stems, whereas lower levels of Pb and Zn were observed in Phragmites australis. In the short-term flooding wetlands, heavy metal contents exhibited a big difference between different tissues of Phragmites australis and Suaeda salsa, and both plant species showed higher levels of Pb and Zn in leaves. Suaeda salsa roots enriched more As and Cd, whereas higher enrichment levels were observed in Phragmites australis leaves, which indicated different transfer capacities of these two wetland plants. The transfer factors for stems and leaves of Phragmites australis in the tidal flooding wetlands significantly differed from those in the short-term flooding wetlands, however, no significant differences in transfer factors for stems and leaves of Suaeda salsa were observed between these two types of wetlands.

Heavy metal solubility in podzolic soils exposed to the alkalizing effect of air pollutants.

PubMed

Haapala, H; Goltsova, N; Lodenius, M

2001-01-01

The heavy metal content of pine forest soil was studied near the boundary between Russia and Estonia, an area characterized by large amounts of acidic and basic air pollutants, mainly sulfur dioxide and calcium. Alkalization dominates the processes in soil, since sulfur is adsorbed only in small quantities, and calcium is much better adsorbed. In addition to Ca, great amounts of Al, Fe, K, and Mg are accumulated in the humus layer due to air pollution. The heavy metal content has increased. The exchangeable content of heavy metals was in many cases much higher in polluted alkaline soils than in non-polluted acidic soils, even the ratio of exchangeable to total metal content being higher in alkaline plots. To avoid a dangerous increase in soluble heavy metal content, it is important to decrease not only the large sulfur emissions of local pollutant sources, but also the alkaline pollutants. A similar concern must be taken into account when liming of acidic forest soils is planned.

Effects of different cleaning treatments on heavy metal removal of Panax notoginseng (Burk) F. H. Chen.

PubMed

Dahui, Liu; Na, Xu; Li, Wang; Xiuming, Cui; Lanping, Guo; Zhihui, Zhang; Jiajin, Wang; Ye, Yang

2014-01-01

The quality and safety of Panax notoginseng products has become a focus of concern in recent years. Contamination with heavy metals is one of the important factors as to P. notoginseng safety. Cleaning treatments can remove dust, soil, impurities or even heavy metals and pesticide residues on agricultural products. But effects of cleaning treatments on the heavy metal content of P. notoginseng roots have still not been studied. In order to elucidate this issue, the effects of five different cleaning treatments (CK, no treatment; T1, warm water (50°C) washing; T2, tap water (10°C) washing; T3, drying followed by polishing; and T4, drying followed by tap water (10°C) washing) on P. notoginseng roots' heavy metal (Cu, Pb, Cd, As and Hg) contents were studied. The results showed that heavy metal (all five) content in the three parts all followed the order of hair root > rhizome > root tuber under the same treatment. Heavy metal removals were in the order of Hg > As > Pb > Cu > Cd. Removal efficiencies of the four treatments were in the order of T2 > T1 > T3 > T4. Treatments (T1-T4) could decrease the contents of heavy metal in P. notoginseng root significantly. Compared with the requirements of WM/T2-2004, P. notoginseng roots' heavy metal contents of Cu, Pb, As and Hg were safe under treatments T1 and T2. In conclusion, the cleaning process after production was necessary and could reduce the content of heavy metals significantly. Fresh P. notoginseng root washed with warm water (T2) was the most efficient treatment to remove heavy metal and should be applied in production.

[Health risk assessment of heavy metals in atmospheric dust of Qingdao City].

PubMed

Zhang, Chun-Rong; Wu, Zheng-Long; Yao, Chun-Hui; Gao, Zong-Jun

2014-07-01

Based on the 89 atmospheric dust samples and soil samples that were collected around Qingdao, we tested and analyzed the contents of Cd, Cr, Cu, Hg, Ni, Pb, Zn. Based on these analysis results, the risk of heavy metals in atmospheric dusts to human health were assessed by using the US EPA Health Risk Assessment Model. Analysis showed that the average contents of Cd, Cr, Cu, Hg, Pb, Zn in the atmospheric dust of Shinan, Shibei and Laoshan districts were the highest. Therefore, the air pollution of these districts was more serious than the districts of Licang, Chengyang and Huangdao. Comparing the average contents of heavy metals in atmospheric dust with those in soil, we found that only the content of Hg in atmospheric dust collected from the districts of Shinan, Shibei and Laoshan was lower than that in the corresponding soil. All the contents of other heavy metals in atmospheric dust were higher than those in corresponding soil. As a whole, the heavy metals in atmospheric dust of Qingdao City showed slight difference and were less harmful to human health. However, it was harmful in some samples to human health if the contents of Cr and Pb in atmospheric dusts of Shinan, Laoshan and Chengyang districts were always kept at such high densities. Besides, the accumulation of heavy metals in atmospheric dust through various approaches and categories may obviously increase the risk of damaging human health.

Characterization of landfill leachates and studies on heavy metal removal.

PubMed

Ceçen, F; Gürsoy, G

2000-10-01

This study covers a thorough characterisation of landfill leachates emerging from a sanitary landfill area. The landfill leachates were obtained in the acidic stage of landfill stabilisation. Their organic content was high as reflected by the high BOD5 (5 day biological oxygen demand) and COD (chemical oxygen demand) values. They were also highly polluted in terms of the parameters TKN (total Kjeldahl nitrogen), NH4-N, alkalinity, hardness and heavy metals. Nickel was present in these wastewaters at a significant concentration. With regard to the high heavy metal content of these wastewaters, several physicochemical removal alternatives for the heavy metals Cu, Pb, Zn, Ni, Cd, Cr, Mn and Fe were tested using coagulation, flocculation, precipitation, base addition and aeration. Additionally, COD removal and ammonia stripping were examined. Co-precipitation with either alum or iron salts did not usually lead to significantly higher heavy metal removal than lime alone. The major methods leading to an effective heavy metal removal were aeration and lime addition. Nickel and cadmium seemed to be strongly complexed and were not removed by any method. Also lead removal proved to be difficult. The results are also discussed in terms of compliance with standards.

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals.

PubMed

Chand, Sukhmal; Singh, Geetu; Patra, D D

2016-08-02

An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg-1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg-1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Ecological and Human Health Risk Assessment of Heavy Metal Content of Atmospheric Dry Deposition, a Case Study: Kermanshah, Iran.

PubMed

Sobhanardakani, Soheil

2018-05-12

The present study was intended to investigate the ecological and human health risk of cobalt, nickel, and vanadium in the atmospheric dry deposition of the Kermanshah city, Iran, in 2015. Totally 54 samples of atmospheric dry deposition were collected from the three regions of the city with different traffic intensity, and after acid digestion of the samples with ultrapure concentrated HNO 3 , the total contents of the metals were determined using inductively coupled plasma optical emission spectrometer (ICP-OES). Also, all statistical analyses were performed using the SPSS statistical package. The atmospheric dry deposition element contents increase according to the following descending order for both autumn seasons: Ni > Co > V. The results of potential ecological risk analysis demonstrated that metals in the samples are in low ecological risk levels, whereas the results of human health risk assessment showed that ingestion is the main exposure pathway of heavy metals in the dust to the local residents compared with inhalation and dermal pathways. Also, the upper limit of the 95% confidence interval (95% UCL) of hazard indices for non-carcinogenic risks of all analyzed metals in the dust samples was within the safe level for both children and adults. On the other hand, the carcinogenic risk levels of Co and Ni were all lower than the acceptable range (10 -6 -10 -4 ) to local citizens. Consequently, the results advocate the necessity of understanding the heavy metal content of atmospheric dry deposition and regular monitoring of air pollution.

PINUS cembra L: histo-anatomical features, antioxidant enzyme activities and heavy metal contents of leaves and long shoots.

PubMed

Lungu, Cristina; Stănescu, Irina; Cojocaru, Sabina Ioana; Ciobanu, C; Ivănescu, Bianca; Miron, Anca

2015-01-01

This study aimed to investigate the histo-anatomical features of the long shoots and leaves (young and mature) of Pinus cembra L.. The activity of antioxidant enzymatic systems and the content of heavy metals were also evaluated. For the histo-anatomical study, the cross-sections were performed by usual techniques. The activity of antioxidant enzymatic systems (superoxide dismutase, catalase and peroxidase) was evaluated by spectrophotometric methods. The content of heavy metals was determined by atomic absorption spectroscopy. The cross-section through the long shoots shows many resiniferous canals and a periderm of variable thickness. The leaf has a triangular shape and only two vascular bundles in the inferior and upper levels. The highest level of superoxide dismutase activity (344.90 U/mg protein) was determined in the long shoots collected from a cembran pine in Vatra Dornei, while the highest level of peroxidase activity (7611.11 U/mg protein) was found in the leaves collected in Calimani Mountains. Cd level in all samples was under the quantification limit. Higher levels of Pb were determined in the long shoots (3 μg/g dry weight for the vegetal material collected in Vatra Dornei and 2.86 μg/g dry weight for the vegetal material collected in Calimani Mountains). Pinus cembra L. leaves show specific elements of subgenus Strobus (a triangular shape of the cross section, one single vascular bundle and two resiniferous canals). The results obtained for the superoxide dismutase and peroxidase activities corroborated with those obtained for the heavy metal contents indicate that antioxidant enzymes play an important role in the protection of Pinus cembra L. against exogenous stress factors.

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 (6content with the SSC application had less influence on the leaching behavior of heavy 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.

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...

Nematodes as bioindicators of soil degradation due to heavy metals.

PubMed

Šalamún, Peter; Renčo, Marek; Kucanová, Eva; Brázová, Tímea; Papajová, Ingrid; Miklisová, Dana; Hanzelová, Vladimíra

2012-11-01

The effect of distance from a heavy metal pollution source on the soil nematode community was investigated on four sampling sites along an 4 km transect originating at the Kovohuty a.s. Krompachy (pollution source). The soil nematode communities were exposed to heavy metal influence directly and through soil properties changes. We quantified the relative effects of total and mobile fraction of metals (As, Cd, Cr, Cu, Pb, and Zn) on soil ecosystem using the nematode community structure (trophic and c-p groups,) and ecological indices (Richness of genera, H', MI2-5, etc.). Pollution effects on the community structure of soil free living nematodes was found to be the highest near the pollution source, with relatively low population density and domination of insensitive taxa. A decrease in heavy metals contents along the transect was linked with an increase in complexity of nematode community. The majority of used indices (MI2-5, SI, H') negatively correlated (P < 0.05 or P < 0.01) with heavy metals content and were sensitive to soil ecosystem disturbance. Contamination by heavy metals has negatively affected the soil environment, which resulted in nematode community structure and ecological indices changes. Results showed that the free-living nematodes are useful tools for bioindication of contamination and could be used as an alternative to the common approaches based on chemical methods.

Compacted Sewage Sludge as a Barrier for Tailings: The Heavy Metal Speciation and Total Organic Carbon Content in the Compacted Sludge Specimen

PubMed Central

Zhang, Huyuan; Zhang, Qing; Yang, Bo; Wang, Jinfang

2014-01-01

Acid mine drainage (AMD) was the main environmental problem facing the mining industry. For AMD had high heavy metals content and low pH, the compacted sewage sludge might be a barrier for tailings whose oxidation and weathering produced AMD, with its own carbon source, microorganism reduction ability and impermeability. To study the heavy metals environmental risk, under the simulate AMD, the deionized water (DW), and the pH 2.1 sulfuric acid water (SA) seepage conditions, respectively, the changes of the chemical speciation of heavy metals Cd, Cu, Fe, Ni, Zn and total organic carbon (TOC) content in the compacted sewage sludge were assessed in the different periods. The results indicated according to the distribution of heavy metals, the potential mobility was for Cd: 6.08 under AMD, 7.48 under SA, ∞ under DW; for Cu: 0.08 under AMD, 0.17 under SA, 0.59 under DW; for Fe: 0.15 under AMD, 0.22 under SA, 0.22 under DW; for Ni: 2.60 under AMD, 1.69 under SA, 1.67 under DW; and for Zn: 0.15 under AMD, 0.23 under SA and 0.21 under DW at the second checking time. TOC content firstly decreased from 67.62±0% to 66.29±0.35%, then increased to 67.74±0.65% under the AMD seepage while TOC decreased to 63.30±0.53%, then to 61.33±0.37% under the DW seepage, decreased to 63.86±0.41%, then to 63.28±0.49% under SA seepage. That indicated under the AMD seepage, the suitable microorganisms communities in the compacted sewage sludge were activated. And the heavy metals environmental risk of compacted sewage sludge was lower with AMD condition than with other two. So the compacted sewage sludge as a barrier for tailings was feasible as the aspect of environmental risk assessment. PMID:24979755

Comparative assessment of heavy metals content during the composting and vermicomposting of Municipal Solid Waste employing Eudrilus eugeniae.

PubMed

Soobhany, Nuhaa; Mohee, Romeela; Garg, Vinod Kumar

2015-05-01

This study was undertaken to have comparative assessment of heavy metals content during composting and vermicomposting processing of Municipal Solid Waste (MSW). Six scenarios were set up in which three experiments were for composting (controls) denoted as S1 for food waste, S2 for paper waste and S3 for yard waste and the corresponding replicates for vermicomposting processes were S4, S5 and S6. Vermicomposting caused significant reduction in Cd (43.3-73.5%), Cr (11.3-52.8%), Cu (18.9-62.5%), Co (21.4-47.6%), Zn (34.6%) and Ni (19.9-49.6%) compared to composting which showed a progressive increase. Addition of worms did not show any effect on Fe and Mn, most probably from the genesis of organic-bound complexes. The efficacy of utilizing Eudrilus eugeniae was indicated by the high values of bioconcentration factors (BCFs) which were in the order of Cd>Ni>Cu>Co>Cr>Zn and the increase amount of these metals in the earthworms' tissue after the vermicomposting processes. Different values of BCFs were obtained for different heavy metals and this accounted that earthworms exert different metabolic mechanisms. Regression analysis of the reduction percentages (R) in relation to BCF showed that RCdtot.S6, RCrtot.S5 and RCutot.S6 were significantly correlated with BCFCd.S6, BCFCr.S5 and BCFCu.S6 respectively. Thus, in comparison to simple composting processes, data analysis suggested the feasibility of inoculating E. eugeniae to MSW in order to mitigate the content of toxic heavy metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spectral Estimation Model Construction of Heavy Metals in Mining Reclamation Areas.

PubMed

Dong, Jihong; Dai, Wenting; Xu, Jiren; Li, Songnian

2016-06-28

The study reported here examined, as the research subject, surface soils in the Liuxin mining area of Xuzhou, and explored the heavy metal content and spectral data by establishing quantitative models with Multivariable Linear Regression (MLR), Generalized Regression Neural Network (GRNN) and Sequential Minimal Optimization for Support Vector Machine (SMO-SVM) methods. The study results are as follows: (1) the estimations of the spectral inversion models established based on MLR, GRNN and SMO-SVM are satisfactory, and the MLR model provides the worst estimation, with R² of more than 0.46. This result suggests that the stress sensitive bands of heavy metal pollution contain enough effective spectral information; (2) the GRNN model can simulate the data from small samples more effectively than the MLR model, and the R² between the contents of the five heavy metals estimated by the GRNN model and the measured values are approximately 0.7; (3) the stability and accuracy of the spectral estimation using the SMO-SVM model are obviously better than that of the GRNN and MLR models. Among all five types of heavy metals, the estimation for cadmium (Cd) is the best when using the SMO-SVM model, and its R² value reaches 0.8628; (4) using the optimal model to invert the Cd content in wheat that are planted on mine reclamation soil, the R² and RMSE between the measured and the estimated values are 0.6683 and 0.0489, respectively. This result suggests that the method using the SMO-SVM model to estimate the contents of heavy metals in wheat samples is feasible.

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.

Analysis of heavy metals in road-deposited sediments.

PubMed

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

2006-07-07

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

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.

Determination of Heavy Metals in Alpinia oxyphylla Miq. Collected from Different Cultivation Regions

PubMed Central

Fu, Yurong; Lai, Weiyong; Zhang, Junqing

2016-01-01

20 batches of Alpinia oxyphylla Miq. were collected from Yunnan, Guangdong, Guangxi, and Hainan province in China. The contents of heavy metals of As, Hg, Pb, Cd, and Cu were determined and compared. The results indicated that geographical source might be a major factor to influence the contents of heavy metals of arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu) in Alpinia oxyphylla Miq. Compared to the criteria of heavy metals, the contents of As, Hg, Pb, and Cd in almost all the samples were in accordance with The Green Trade Standards. The contents of Cu were higher than the criteria for heavy metals except the samples from Changxing town, Qiongzhong county, Maoyang town, Qiongzhong county, Wupo town, Tunchang county, and Nanlv town, Tunchang county, in Hainan province. The best cultivation regions of Alpinia oxyphylla Miq. were from Changxing town, Qiongzhong county, Maoyang town, Qiongzhong county, Wupo town, Tunchang county, and Nanlv town, Tunchang county, in Hainan province. This research would provide the scientific basis for quality control and standardization of Alpinia oxyphylla Miq. PMID:27293963

Heavy metal contaminants in yerberia shop products.

PubMed

Levine, Michael; Mihalic, Jason; Ruha, Anne-Michelle; French, Robert N E; Brooks, Daniel E

2013-03-01

Complementary and alternative medications, including the use of herbal medications, have become quite popular in the USA. Yerberias are found throughout the southwest and specialize in selling Hispanic herbal products. The products sold in these stores are not regulated by any governmental agency. Previous reports have found Ayurvedic medications contain high levels of lead, mercury, and arsenic. The primary purpose of this study is to examine the prevalence of heavy metal contaminants sold at Yerberia stores in the southwest. Yerberias in the Phoenix, Arizona area were identified via search of an on-line search engine using the words "Yerberia Phoenix." Every second store was selected, and products were purchased using a standard script. The products were subsequently analyzed for mercury, lead, and arsenic. The main outcome is the prevalence of heavy metal content in over-the-counter "cold" medications purchased at a Yerberia. Twenty-two samples were purchased. One product contained pure camphor (2-camphone) and was subsequently not further analyzed. Of the 21 samples analyzed, lead was found in 4/21 (19.4 %). Arsenic and mercury were in 1/21 (4.8 %) each. Because two samples contained two heavy metals, the total prevalence of heavy metals was 4/21 (19.4). Heavy metal contaminants are commonly encountered in over-the-counter herbal "cold" medications purchased at Yerberias in the southwest.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Topical report. [Metal content in Cerro Negro heavy petroleum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearson, C.D.; Green, J.A.; Green, J.B.

1988-01-01

Nickel, vanadium, and iron were determined in distilled and chromatographically separated fractions from Cerro Negro heavy petroleum. Corresponding data were also obtained on two samples of Wilmington, California, heavy crude and one Mayan, Mexico, heavy oil for comparison. For the Cerro Negro crude, the ratio of porphyrinic to nonporphyrinic forms of metals was also determined on selected fractions using visible spectroscopy. In all four heavy petroleums, significant levels of metals were found only in the highest boiling distillate available, ca. 550-700/sup 0/C (1000-1300/sup 0/F), and the residue. Typically, the distillation residue contained >95 percent of a given metal. All crudesmore » contained metalloorganics of the following types: strongly acidic, weakly acidic, strongly basic, weakly basic, and neutral, but the relative distribution of metals among each class was crude dependent. Generally, nickel and vanadium distributions for a given crude followed one another very closely, while those for iron were often inconclusive because of poor mass balances for that element. Attempts to concentrate metalloorganics through liquid chromatographic separation methods largely unsuccessful. The wide variety of types of metal-containing compounds in the crudes examined precluded the use of a single approach for their isolation or preconcentration. 21 refs., 1 fig., 12 tabs.« less

Immobilization of heavy metals on pillared montmorillonite with a grafted chelate ligand.

PubMed

Brown, Loren; Seaton, Kenneth; Mohseni, Ray; Vasiliev, Aleksey

2013-10-15

The objective of this work was the development of an efficient adsorbent for irreversible immobilization of heavy metals in contaminated soils. The adsorbent was prepared by pillaring of montmorillonite with silica followed by grafting of a chelate ligand on its surface. Obtained adsorbent was mesoporous with high content of adsorption sites. Its structure was studied by BET adsorption of N2, dynamic light scattering, and scanning electron microscopy. The adsorption capacity of the organoclay was measured by its mixing with contaminated kaolin and soil samples and by analysis of heavy metal contents in leachate. Deionized water and 50% acetic acid were used for leaching of metals from the samples. As it was demonstrated by the experiments, the adsorbent was efficient in immobilization of heavy metals not only in neutral aqueous media but also in the presence of weak acid. As a result, the adsorbent can be used for reduction of heavy metal leaching from contaminated sites. Copyright © 2013 Elsevier B.V. All rights reserved.

Does heavy metal exposure affect the condition of Whitethroat (Sylvia communis) nestlings?

PubMed

Turzańska-Pietras, Katarzyna; Chachulska, Justyna; Polechońska, Ludmiła; Borowiec, Marta

2018-03-01

Anthropogenic pollution results in high concentrations of heavy metals in the environment. Due to their persistence and a high potential for bioaccumulation, metals are a real threat for birds breeding in industrial areas. The aim of the present study has been to explore the contents of heavy metals (arsenic As, cadmium Cd, chromium Cr, copper Cu, iron Fe, nickel Ni, lead Pb and zinc Zn) in the excreta of Whitethroat (Sylvia communis) nestlings living in polluted environment and to investigate the relationship between these contents and the nestlings' condition. Excrement samples contained all the studied elements. The contents of arsenic, cadmium, copper and zinc in the excreta of nestlings from nests located close to a slag dump were several times higher than in the soil near the dump, which suggested accumulation in food consumed by the birds. Condition parameters (body mass and haemoglobin concentration) were not related to heavy metal concentrations in the nestlings' excreta, except of Zn. It is possible that Whitethroats are able to detoxicate heavy metals to a certain extent. Detailed, multi-element analysis of the environment, food and bird tissues or excreta should be performed to explore relations between different chemicals and bird condition.

Stress induced by heavy metals on breeding of magpie (Pica pica) from central Iran.

PubMed

Zarrintab, Mohammad; Mirzaei, Rouhollah

2017-09-01

The aim of this study was to address the impacts of some heavy metals (Cd, Pb, Zn, Ni and Cu) contamination on laying behavior, egg quality and breeding performance of Pica pica in north of Isfahan Province, Iran. During the breeding season of 2013, magpie's egg content and eggshell as well as nestling excrements and feathers were collected and total concentrations of heavy metals were measured by ICP-OES. Except for Zn in nestling feathers, the significantly higher concentrations of heavy metals were observed in nestling excrements than other samples. Also, comparison of heavy metals concentrations in egg content and eggshell showed that egg content had significantly higher concentrations of Zn and Pb, instead eggshell had significantly higher amount of Cu and Cd. Except for Cu, all heavy metals concentrations in eggshell had a negative relationship with morphological characters; and also concentration of Cu in egg content showed a significantly negative correlation with egg weight and volume. The most of heavy metals in nestling feathers and excrements had strongly positive correlations with each other. Also all heavy metals levels in eggshell and egg content had significantly positive correlations (except for Cu). Unhatched eggs had significantly lower weight but also greater levels of Zn, Cd, and Pb, than randomly collected eggs. No significant differences were observed for morphometric measurements of eggs between different sites, however, a decreased gradient was observed in egg volume toward the brick kiln site. Samples collected in brick kiln site accumulated higher concentrations of heavy metals than other sites. Although numbers of clutch size in brick kiln site were significantly higher than other sites, however, other breeding variable were lower than other sites. It can be suggested that ecosystem contamination may be caused to decrease the reproduction rate of Pica pica in brick kiln, probably by laying more poor quality eggs per clutch and nestling

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.

Influence of Heavy Metal Stress On Water Regime of A Model Forest Ecosystem

NASA Astrophysics Data System (ADS)

Menon, M.; Abbaspour, K. C.; Schulin, R.

Among various toxic substances that contaminate the soil, the effects of heavy metals are particularly severe on all aspects of soil-plant system. The Swiss Federal Institute for Forest Snow and Land Research (WSL) is addressing comprehensively the issue of heavy metal toxicity in a forest ecosystem in a project titled Sfrom cell to treeT. As & cedil; part of the above project an investigation is being carried out to evaluate the impact of heavy metal stress on water regime of a young forest ecosystem grown in sixteen open top lysimeters. The factorial treatments of the lysimeters include variations of rainwa- ter acidity (acidic, neutral), subsoil type (acidic, calcareous), and heavy metal con- centration (with and without heavy metals in the top 20 cm). Filling of lysimeters was completed in November 1999. Each model ecosystem was planted in spring 2000 with the same collection of trees and herbaceous plants. Each lysimeters is equipped with tensiometers for monitoring of pressure head, time domain reflectometry for moni- toring of water content, and sprinkler devices for application of controlled irrigation. Drainage water data are measured regularly from the canisters installed at the bot- tom of lysimeters and evapotranspiration is calculated through water balancing. Our preliminary analyses of the data shoed the following results. Weekly data collected from May to October 2001 indicated higher amount of percolating water in acidic soil compared to the neutral soil due to textural difference. At 12 cm depth in both soils, control and acidic rain showed lower water potential than heavy metal and combina- tion of acidic rain with heavy metal treatments. In lower depths, water potential did not show much difference between treatments. Water contents showed differences be- tween treatments in the upper part of the profile where the soil is contaminated with heavy metals. Higher water content was observed in heavy metal treatment at 0-25 cm depth than 25-50 cm

[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.

Model evaluation of plant metal content and biomass yield for the phytoextraction of heavy metals by switchgrass.

PubMed

Chen, Bo-Ching; Lai, Hung-Yu; Juang, Kai-Wei

2012-06-01

To better understand the ability of switchgrass (Panicum virgatum L.), a perennial grass often relegated to marginal agricultural areas with minimal inputs, to remove cadmium, chromium, and zinc by phytoextraction from contaminated sites, the relationship between plant metal content and biomass yield is expressed in different models to predict the amount of metals switchgrass can extract. These models are reliable in assessing the use of switchgrass for phytoremediation of heavy-metal-contaminated sites. In the present study, linear and exponential decay models are more suitable for presenting the relationship between plant cadmium and dry weight. The maximum extractions of cadmium using switchgrass, as predicted by the linear and exponential decay models, approached 40 and 34 μg pot(-1), respectively. The log normal model was superior in predicting the relationship between plant chromium and dry weight. The predicted maximum extraction of chromium by switchgrass was about 56 μg pot(-1). In addition, the exponential decay and log normal models were better than the linear model in predicting the relationship between plant zinc and dry weight. The maximum extractions of zinc by switchgrass, as predicted by the exponential decay and log normal models, were about 358 and 254 μg pot(-1), respectively. To meet the maximum removal of Cd, Cr, and Zn, one can adopt the optimal timing of harvest as plant Cd, Cr, and Zn approach 450 and 526 mg kg(-1), 266 mg kg(-1), and 3022 and 5000 mg kg(-1), respectively. Due to the well-known agronomic characteristics of cultivation and the high biomass production of switchgrass, it is practicable to use switchgrass for the phytoextraction of heavy metals in situ. Copyright © 2012 Elsevier Inc. All rights reserved.

Analysis of physical composition and heavy metals pollution of municipal solid waste (MSW) in Beijing

NASA Astrophysics Data System (ADS)

Zhang, H. B.; Zhang, H. Y.; Wang, G. Q.; Bai, X. J.

2018-03-01

By using on-site sampling and physical-chemical analysis, the physical composition and the contents of heavy metals in Beijing MSW were researched. The result showed that the main components of MSW in Beijing are mainly kitchen waste, the average content of kitchen waste are more than 60% and 50% in summer and in winter, respectively. The pollution of Cu, Hg and Cr are all more serious for MSW in Haidian and Dongcheng district. The heavy metal pollution of MSW in summer is higher than that in winter in Beijing. Seasonal impacts should be taken into consideration when dealing with MSW. The content of heavy metals in MSW exceeded the background value of soil in Haidian and Dongcheng districts. In order to reduce heavy metal pollution, the MSW should be separated collection and treated.

Spectral Estimation Model Construction of Heavy Metals in Mining Reclamation Areas

PubMed Central

Dong, Jihong; Dai, Wenting; Xu, Jiren; Li, Songnian

2016-01-01

The study reported here examined, as the research subject, surface soils in the Liuxin mining area of Xuzhou, and explored the heavy metal content and spectral data by establishing quantitative models with Multivariable Linear Regression (MLR), Generalized Regression Neural Network (GRNN) and Sequential Minimal Optimization for Support Vector Machine (SMO-SVM) methods. The study results are as follows: (1) the estimations of the spectral inversion models established based on MLR, GRNN and SMO-SVM are satisfactory, and the MLR model provides the worst estimation, with R2 of more than 0.46. This result suggests that the stress sensitive bands of heavy metal pollution contain enough effective spectral information; (2) the GRNN model can simulate the data from small samples more effectively than the MLR model, and the R2 between the contents of the five heavy metals estimated by the GRNN model and the measured values are approximately 0.7; (3) the stability and accuracy of the spectral estimation using the SMO-SVM model are obviously better than that of the GRNN and MLR models. Among all five types of heavy metals, the estimation for cadmium (Cd) is the best when using the SMO-SVM model, and its R2 value reaches 0.8628; (4) using the optimal model to invert the Cd content in wheat that are planted on mine reclamation soil, the R2 and RMSE between the measured and the estimated values are 0.6683 and 0.0489, respectively. This result suggests that the method using the SMO-SVM model to estimate the contents of heavy metals in wheat samples is feasible. PMID:27367708

Soil degradation in the tropical forests of the Dominican Republic's Pedernales province in relation to heavy metal contents.

PubMed

Hernández, Ana Jesus; Alexis, Stervin; Pastor, Jesús

2007-05-25

Two of the National Parks of the only Biosphere Reserve in the Caribbean Islands, the Jaragua-Bahoruco-Enriquillo reserve, occur mostly within the Pedernales province (Dominican Republic). In these National Parks, Jaragua and Bahoruco, almost every tropical forest ecosystem is represented, as are the land uses most common to the Dominican Republic. Despite soil being a key natural resource that needs to be considered in any sustainable development programme, the literature contains very little information on the soils of this region. In this study, we analysed 41 topsoil samples representing the main forest types and land uses of the province. The factors examined were fertility (OM, N, P, K) and heavy metal contents (Cu, Cr, Pb, Cd, Ni, Zn). Mean OM, N and total and available metal levels were almost invariably higher in the natural forest soils compared to those given over to human activities, especially cultivated soils. This difference suggests the uptake of metals by the crops and, to a lesser extent, by animals feeding on crop remains and grassland plants. This hypothesis is supported by high total and available metal contents, especially of Zn, Cu, Pb and, in smaller measure, of Cr recorded in the solid waste landfill of the city of Pedernales. It appears that the cutting down and burning practices of a nomad type of cultivation, as well as the pressures of intensive agriculture and livestock rearing have resulted in heavy metals bound to the soil's OM. We propose this is an important point to consider for the management of these lands.

In situ distributions and characteristics of heavy metals in full-scale landfill layers.

PubMed

He, Pin-Jing; Xiao, Zheng; Shao, Li-Ming; Yu, Ji-Yu; Lee, Duu-Jong

2006-10-11

The leachate from methanogenic landfill normally contains low concentrations of heavy metals. Little samples had ever been collected from the full-scale landfill piles owing to technical difficulty for well drilling. We drilled two wells in Hangzhou Tianziling landfill, 20 m and 32 m in depth each, and collected solid samples of waste age of 1-4 years from both wells. The total amounts, the sequentially extracted amounts, and the chemical binding forms of heavy metals of the samples collected at different depths were measured. With the correlation between leachate production amount and the yearly rainfall amount, the leached ratio of the heavy metals were estimated only 0.13%, 1.8%, 0.15%, and 0.19% of Cu, Cd, Pb, and Zn, respectively. The heavy metals amounts in the main compositions of MSW, like glass, food waste, paper, coal cinders, were measured using fresh MSW samples. Afterward, the contents of heavy metals initially landfilled were estimated. A positive correlation was noted between the measured and the estimated initial contents of heavy metals, indicating that the low migration of heavy metals in landfill layers. However, among the metals investigated, Zn has shown better mobility inside landfill layers. Acid volatile sulfide (AVS) and the simultaneously extracted metals (SEM) were measured for all collected samples with optimal reaction conditions identified to yield nearly perfect sulfide recovery as follows: 100 g wet samples, 80 mL min(-1) N(2) flow rate, reaction time of 150 min. The SEM/AVS ratios ranged 25-45, indicating that the AVS was insufficient to immobilize the SEM. Sequential extraction using six-fraction scheme revealed that the sum of exchangeable and the avid soluble fractions of heavy metals follow: Zn>Cd>Cu, Ni, Pb>Cr. The insoluble fraction of heavy metals in MSW was high, for instance, over 80% for Cr and Pb high insoluble fractions of heavy metals in the landfilled MSW and the sorption capability of the methanogenic landfill layers

Antimicrobial resistance, heavy metal resistance and integron content in bacteria isolated from a South African tilapia aquaculture system.

PubMed

Chenia, Hafizah Y; Jacobs, Anelet

2017-11-21

Antibacterial compounds and metals co-select for antimicrobial resistance when bacteria harbour resistance genes towards both types of compounds, facilitating the proliferation and evolution of antimicrobial and heavy metal resistance. Antimicrobial and heavy metal resistance indices of 42 Gram-negative bacteria from a tilapia aquaculture system were determined to identify possible correlations between these phenotypes. Agar dilution assays were carried out to determine susceptibility to cadmium, copper, lead, mercury, chromate and zinc, while susceptibility to 21 antimicrobial agents was investigated by disk diffusion assays. Presence of merA, the mercury resistance gene, was determined by dot-blot hybridizations and PCR. Association of mercury resistance with integrons and transposon Tn21 was also investigated by PCR. Isolates displayed a high frequency of antimicrobial (erythromycin: 100%; ampicillin: 85%; trimethoprim: 78%) and heavy metal (Zn2+: 95%; Cd2+: 91%) resistance. No correlation was established between heavy metal and multiple antibiotic resistance indices. Significant positive correlations were observed between heavy metal resistance profiles, indices, Cu2+ and Cr3+ resistance with erythromycin resistance. Significant positive correlations were observed between merA (24%)/Tn21 (24%) presence and heavy metal resistance profiles and indices; however, significant negative correlations were obtained between integron-associated qacE∆1 (43%) and sulI (26%) gene presence and heavy metal resistance indices. Heavy metal and antimicrobial agents co-select for resistance, with fish-associated, resistant bacteria demonstrating simultaneous heavy metal resistance. Thus, care should be taken when using anti-fouling heavy metals as feed additives in aquaculture facilities.

Heavy metal contamination, microbiological spoilage and biogenic amine content in sushi available on the Polish market.

PubMed

Kulawik, Piotr; Dordevic, Dani; Gambuś, Florian; Szczurowska, Katarzyna; Zając, Marzena

2018-05-01

The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed. All of the nori samples contained high levels of Cd (2.122 mg kg -1 ), Ni (0.715 mg kg -1 ), As (34.56 mg kg -1 ) and Pb (0.659 mg kg -1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg -1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 10 6  cfu g -1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg -1 . Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

[Heavy Metals Pollution in Topsoil from Dagang Industry Area and Its Ecological Risk Assessment].

PubMed

Zhang, Qian; Chen, Zong-juan; Peng, Chang-sheng; Li, Fa-sheng; Gu, Qing-bao

2015-11-01

Based on previous studies and field investigation of Dagang industry area in Tianjin, a total of 128 topsoil samples were collected, and contents of 10 heavy metals (As, Cd, Cr, Co, Cu, Pb, Ni, V, Zn and Hg) were determined. The geoaccumulation index and geostatistics were applied to examine the degree of contamination and spatial distribution of heavy metals in topsoil. The assessment on ecological risk of heavy metals was carried out using Hakanson's method, and the main resources of the heavy metals were analyzed as well. It was found that As, Cd and Co had the highest proportions exceeding Tianjin background value, which were 100%, 97.66% and 96.88%, respectively; the heavy-metal content increased to some extent comparing with that in 2004, and the pollutions of As and Cd were the worst, and other metals were at moderate pollution level or below. The ecological risks of heavy metals were different in topsoil with different land use types, the farmland soil in the southwest as well as soils adjacent to the industrial land were at relatively high potential ecological risk level, and the integrated ecological risk index reached up to 1 437.37. Analysis of correlation and principal component showed that traffic and transportation as well as agricultural activities might be the main resources of heavy metals in the area, besides, the industrial activities in the region might also affect the accumulation of heavy metals.

[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.

Will heavy metals in the soils of newly submerged areas threaten the water quality of Danjiangkou Reservoir, China?

PubMed

Song, Zhixin; Shan, Baoqing; Tang, Wenzhong; Zhang, Chao

2017-10-01

Soil heavy metal contents were measured in newly submerged areas of the Danjiangkou Reservoir, China. We aimed to determine the heavy metal distribution in this area and the associated ecological risk. Most of these heavy metal contents (except Pb and Mn) suggest enrichment compared with the background values of soils from Henan Province, especially As and Cd with mean geo-accumulation index (I geo ) values of 0.84 and 0.54. The spatial analysis results indicated that the highest heavy metal contents were distributed in the arable soils above 160m elevation, whereas low heavy metal contents were observed under other land-use types above 160m elevation. According to I geo and EF values, Cd was the major heavy metal contaminant in the newly submerged area, Cr, Pb and Mn mainly originated from natural geochemical sources. In contrast, Ni, Cd, As, Cu, and Zn mainly originated from anthropogenic sources. Evaluation using the potential ecological risk (PER) method indicated that PER of individual elements were low in the studied soils, and the comprehensive PER index was at a moderate level, indicating heavy metals in the soils of newly submerged areas may not threaten the water quality of Danjiangkou Reservoir, especially in winter. Copyright © 2017 Elsevier Inc. All rights reserved.

[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.

Heavy metals in fish tissues/stomach contents in four marine wild commercially valuable fish species from the western continental shelf of South China Sea.

PubMed

Gu, Yang-Guang; Lin, Qin; Huang, Hong-Hui; Wang, Liang-Gen; Ning, Jia-Jia; Du, Fei-Yan

2017-01-30

The concentrations of heavy metals (Cd, Pb, Cr, Ni, Cu and Zn) were determined in four commercially valuable fish species (Thunnus obesus, Decapterus lajang, Cubiceps squamiceps and Priacanthus macracanthus), collected in the western continental shelf of the South China Sea. Concentrations of Cd, Pb, Cr, Ni, Cu, and Zn in fish muscles were 0.006-0.050, 0.13-0.68, 0.18-0.85, 0.11-0.25, 0.12-0.77, and 2.41-4.73μg/g, wet weight, respectively. Concentrations of heavy metals in all species were below their acceptable daily upper limit, suggesting human consumption of these wild fish species may be safe, with health risk assessment based on the target hazard quotients (THQ) and total THQ, indicating no significant adverse health effects with consumption. The average concentrations of Zn were higher in gills than in stomach contents, backbones or muscle, while conversely, the other heavy metals had higher concentrations in stomach contents than in other tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of trace and heavy metals in some commonly used medicinal herbs in Ayurveda.

PubMed

Nema, Neelesh K; Maity, Niladri; Sarkar, Birendra K; Mukherjee, Pulok K

2014-11-01

Traditionally, the herbal drugs are well established for their therapeutic benefits. Depending upon their geographical sources sometimes the trace and heavy metals' content may differ, which may lead to severe toxicity. So, the toxicological and safety assessment of these herbal drugs are one of the major issues in recent days. Eight different plant species including Aloe vera, Centella asiatica, Calendula officinalis, Cucumis sativus, Camellia sinensis, Clitoria ternatea, Piper betel and Tagetes erecta were selected to determine their heavy and trace metals content and thereby to assure their safer therapeutic application. The trace and heavy metals were detected through atomic absorption spectrometry analysis. The selected medicinal plant materials were collected from the local cultivated regions of West Bengal, India, and were digested with nitric acid and hydrochloric acid as specified. Absorbance was measured through atomic absorption spectrometer (AA 303) and the concentration of different trace and heavy metals in the plant samples were calculated. The quantitative determinations were carried out using standard calibration curve obtained by the standard solutions of different metals. The contents of heavy metals were found to be within the prescribed limit. Other trace metals were found to be present in significant amount. Thus, on the basis of experimental outcome, it can be concluded that the plant materials collected from the specific region are safe and may not produce any harmful effect of metal toxicity during their therapeutic application. The investigated medicinal plants contain trace metals such as copper (Cu), chromium (Cr), manganese (Mn), iron (Fe) and nickel (Ni) as well as heavy metals such as arsenic (As), lead (Pb) and mercury (Hg), which were present within the permissible limit. © The Author(s) 2012.

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

NASA Astrophysics Data System (ADS)

Sakan, Sanja; Đorđević, Dragana

2017-04-01

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

Effects of moisture content and initial pH in composting process on heavy metal removal characteristics of grass clipping compost used for stormwater filtration.

PubMed

Khan, Eakalak; Khaodhir, Sutha; Ruangrote, Darin

2009-10-01

Heavy metals are common contaminants in stormwater runoff. One of the devices that can be used to effectively and economically remove heavy metals from runoff is a yard waste compost stormwater filter. The primary goal of composting is to reduce waste volume rather than to produce stormwater filter media. Moisture content (MC) and initial pH, the two important parameters in composting, were studied for their effects on yard waste volume reduction and heavy metal adsorption performances of the compost. The main objective of this investigation was to examine whether the conditions that provided high yard waste volume reduction would also result in compost with good heavy metal removal performances. Manila grass was composted at different initial pHs (5-9) and MCs (30-70%) and the composts were used to adsorb cadmium, copper, lead and zinc from water. Results indicated that MC is more critical than initial pH for both volume reduction and production of compost with high metal adsorption performances. The most optimal conditions for the two attributes were not exactly the same but lower MCs of 30-40% and pH 7 or higher tended to satisfy both high volume reduction and effective metal adsorption.

Hyperspectral estimation of soil heavy metals in Guanzhong area, Shaanxi province

NASA Astrophysics Data System (ADS)

Liu, Jinbao; Cheng, Jie; Wang, Huanyuan; Tong, Wei; Ma, Zenghui

2017-10-01

In this study, the contents of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pub in 44 soil samples were collected from Fufeng County, Yangling County and Wugong County, Shaanxi Province and were used as data sources. ASD Field Spec HR (350 ˜ 2500 nm), and then the NOR, MSC and SNV of the reflectance were pretreated, the first deviation, second deviation and reflectance reciprocal logarithmic transformation were carried out. The optimal hyper spectral estimation model of nine heavy metal elements of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pb was established by regression method. Comparing the reflection characteristics of different heavy metal contents and the effect of different pretreatment methods on the establishment of soil heavy metal spectral inversion model. The results show that: (1) the reflectance spectrum improves the signal-to-noise ratio of the reflectance spectrum after the transformation of NOR, MSC and SNV. Combining differential transformation can improve the information of heavy metal elements in the soil, and use the correlation band energy significantly improve the stability and predictability of the model. (2) The modeling accuracy of the optimal model of nine heavy metal spectra of Cr, Mn, Ni, Cu, and Zn, As, Cd, Hg and Pb by PLSR method were 0.7002, 0.7852, 0.687, 0.8036, 0.8619, 0.5765, 0.5451, 0.9912, and 0.6182.

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.

Spatial and vertical distribution of soil physico-chemical properties and the content of heavy metals in the pedosphere in Poland

Treesearch

Marek Degorski

1998-01-01

The lithological and petrographical characteristics of soil pedogenesis was determined, and the spatial and vertical distribution of some soil physico-chemical properties (including heavy metal content) were studied along two transects in Poland. The genetic horizon for 22 soil profiles were described for particle size and petrographic composition, quartz grain...

Magnetic susceptibility as an indicator of heavy metal contamination in compost.

PubMed

Paradelo, Remigio; Moldes, Ana Belén; Barral, María Teresa

2009-02-01

One of the main restrictions to the agronomic use of compost is the excess of heavy metals, which are often present due to inadequate separation of biodegradable fractions from non-degradable or inert materials. Magnetic susceptibility (MS) measurements are a simple technique that has been reported as a useful tool for assessing anthropogenic pollution, especially heavy metal pollution on soil and sediment samples. The close relationship of MS with heavy metal contamination has been proved by combined analyses of chemical and magnetic data. In this study, the MS and total heavy metal concentrations of eight composts from different origins were determined; all composts were passed under a magnet to remove the magnetic material, and total heavy metals were determined again. In our work, high correlations were found between magnetic susceptibility and total Cd, Zn, Pb, Cr and Ni, thus confirming the applicability of MS measurement as a proxy for heavy metal contamination in compost quality assessments. The application of a magnet over the composts reduced the MS as well as the heavy metal content, the reduction of Fe and MS being the most significantly correlated. Thus, the inclusion of an additional magnetic separation step in the post-process compost finishing could be envisaged.

[Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

PubMed

Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

2014-09-01

The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb < Cu < Cd < Cr < As < Zn. The heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd < Cu < As < Cr contents of Cr, Cu, Cd appeared at EM3 station. The contents of heavy metals in surface sediments was in the order of Cd contents of Cr, Cu, Cd and As in surface sediments also appeared at EM3 station. Temperature, pH, DO, EC and other factors affected the distribution of heavy metals in water, suspended solids and sediment. In particular, the effects of salinity and suspended solids matter were most significant. The integrated pollution index assessment showed that the water quality was good except individual stations. The geoaccumulation index assessment showed that As was the major pollution element in surface sediments.

[Heavy metals in environmental media around drinking water conservation area of Shanghai].

PubMed

Shi, Gui-Tao; Chen, Zhen-Lou; Zhang, Cui; Bi, Chun-Juan; Cheng, Chen; Teng, Ji-Yan; Shen, Jun; Wang, Dong-Qi; Xu, Shi-Yuan

2008-07-01

The levels of heavy metals in Shanghai drinking water conservation area were determined, and the spatial distributions and main sources of heavy metals were investigated. Moreover, the ecological risk assessment of heavy metals was conducted. Some conclusions can be drawn as follows: (1) The average concentrations of Cd, Hg, Pb, Cu, Zn, Ni, Cr and As in road dust were 0.80, 0.23, 148.45, 127.52, 380.57, 63.17, 250.38 and 10.37 mg x kg(-1) respectively. In terms of the pollution level, the values of soils were relatively lower, with the mean contents of 0.16 (Cd), 0.33 (Hg), 30.14 (Pb), 30.66 (Cu), 103.79 (Zn), 24.04 (Ni), 65.75 (Cr) and 6.31 mg x kg(-1) (As) severally; meanwhile the average levels of heavy metals in vegetables were 0.010 (Cd), 0.016 (Hg), 0.36 (Pb), 12.80 (Cu), 61.69 (Zn), 2.04 (Ni), 2.41 (Cr) and 0.039 mg x kg(-1) (As) respectively. (2) Semivariogram and multivariate analysis indicated that heavy metals pollution of soils was induced by anthropogenic activities mostly, and the pollutants produced by traffic were the major source of heavy metals in road dust. (3) The order for heavy metal enrichment coefficients of vegetables was as following: Zn (0.589) > Cu (0.412) > 0.102 (Ni) > Cd (0.059) > Cr (0.061) > Hg (0.056) > Pb (0.012) > As (0.007), and the results indicated that Cd and Zn in vegetables were mainly from the soils, and the other metals were probably from the pollutants in the atmosphere. (4) Sediments in drinking water conservation area were probably derived from soils around; however, there was no significant relationship between heavy metals contents of them. (5) The results of ecological risk assessment of heavy metals showed that heavy metals in soils were in no-warning to warning situation, and warning to light-warning situation for road dust and vegetables. The fuzzy synthesis judgment for all the environmental media around drinking water conservation area was warning to light-warning.

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

Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

PubMed

Yang, Pingguo; Ge, Jing; Yang, Miao

2017-06-01

The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg -1 ), Zn (99.72 mg kg -1 ), Pb (90.99 mg kg -1 ), Cu (36.14 mg kg -1 ). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

[Study on distribution characteristics and potential ecological risk of soil heavy metals in the Yellow River beach region in Kaifeng City].

PubMed

Zhang, Peng-yan; Qin, Ming-zhou; Chen, Long; Hu, Chang-hui; Zhao, Ya-ping; Dong, Wei-jun

2013-09-01

The distributions, soil environment status and potential ecological risk of heavy metals were studied in beach soil of returning the cropland into Yellow River beach region in Kaifeng by the Nemerows and Håkansons methods. The results showed that (1) as Among the average contents of the five heavy metals Pb, Cr, Hg, As and Cd, the highest was the average content of Cr, and the lowest was the average content of Pb and Hg. In addition to Hg, the coefficients of variation of other heavy metals were relatively small, indicating that the content of heavy metals was quite different at different sites, and to some extent, relecting that Hg, As and Pb were the major elements polluting the soil, among which, Pb pollution was the pollution with universality. There was little difference in the contents of Cr and Cd from village to village the coefficient of variation was small, and the contents were below the national standard level. (2) There was significant difference in the spatial distribution of soil heavy metal elements in the upper, the middle and lower sections of the study area. The upper section was clean, the middle section was slightly polluted, and the lower section was enriched with pollutants. (3) The distribution of heavy metals in the beach region inside and outside the levees of Yellow River was closely related to the distribution of the residential regions. In the upper section of the beach region (southwest), the population was large and the contents of heavy metals were high. The contents of heavy metals were lower in the near river zone than outside the levees of Yellow River. And the heavy metal contents in the middle and lower section were higher than those outside the levees of Yellow River, while the lower section (northwest) showed a tendency of pollution enrichment. (4) In the view of the average individual potential ecological risk index of heavy metals (E(r)i), the potential ecological risk of Hg reached intense levels, and the potential

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

Selected heavy metals speciation in chemically stabilised sewage sludge

NASA Astrophysics Data System (ADS)

Wiśniowska, Ewa; Włodarczyk-Makuła, Marła

2017-11-01

Selected heavy metals (Pb, Ni, Cd) were analysed in soil, digested sewage sludge as well as in the sludge stabilised with CaO or Fenton's reagent. The dose of Fenton's reagent was as follows: Fe2+ = 1g.L-1, Fe2+/H2O2=1:100; stabilisation lasted for 2 h. Dose of CaO was equal to 1 g CaO.g d.m.-1 Total concentration of all metals in the digested sewage sludge was higher than in the soil. Chemical stabilisation of sludge with Fenton's reagent increased total metal content in the sludge as a result of total solids removal. Opposite effect was stated when the sludge was mixed with CaO. Also chemical fractions of heavy metals were identified (exchangeable, carbonate bound, iron oxides bound, organic and residual). The results indicate that stabilisation of the sludge with Fenton's reagent increased mobility of heavy metals compared to the digested sludge. Amendment of CaO increased percent share of examined metals in residual fraction, thus immobilised them and decreased their bioavailability.

Investigation of the effects of phosphate fertilizer application on the heavy metal content in agricultural soils with different cultivation patterns.

PubMed

Cheraghi, Mehrdad; Lorestani, Bahareh; Merrikhpour, Hajar

2012-01-01

The use of phosphate fertilizers is essential in agriculture, because they supply farmland with nutrients for growing plants. However, heavy metals might be included as impurities in natural materials and minerals, so heavy metals can also be present in phosphate fertilizers or other chemical fertilizers. The aim of this work was to assess the heavy metal content and contamination status of agricultural soils in the Hamadan province of Iran used for the cultivation of different crops, including cucumber, potatoes, and sugar beet. Surface soil samples were collected and analyzed to determine the total concentration of specific elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), before the pollution index was calculated for each element. Soils used for the cultivation of the three types of crop were not contaminated with As, Cr, Cu, Pb, or Zn. However, the pollution indices for Cd were 1.1, 4.4, and 3.8 in cucumber, potato, and sugar beet fields, respectively, which indicated moderate, high, and high levels of contamination, respectively. Soils from potato and sugar beet fields were heavily contaminated with Cd, which may have resulted from long-term overuse of phosphate fertilizers.

Inter- and intra-specific competition of duckweed under multiple heavy metal contaminated water.

PubMed

Zhao, Zhao; Shi, Huijuan; Kang, Xianjiang; Liu, Cunqi; Chen, Lingci; Liang, Xiaofei; Jin, Lei

2017-11-01

The influences of intra- and inter-species competition on ecosystems are poorly understood. Lemna aequinoctialis and Spirodela polyrhiza were used to assess the effects of exposure to different concentrations of multiple heavy metals (copper-cadmium-zinc), when the plants were grown in mixed- or mono-culture. Parameters assessed included relative growth rate (RGR), content of chlorophyll, glutathione (GSH), malondialdehyde (MDA), as well as the activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD). Inter-specific competition was affected by metal concentration, with results indicating that inter-specific competition significantly affected duckweed growth and metal uptake in different heavy metal exposure conditions. Inter-specific competition increased growth rate of duckweed under high metal concentrations, although when compared with intra-specific competition, it caused no obvious differences under low metal concentrations. The growth of L. aequinoctialis was further increased in mixed culture when exposed to high metal concentrations, with inter-specific competition increasing the content of cadmium and zinc, while decreasing copper content of L. aequinoctialis compared with under intra-specific conditions. Conversely, inter-specific competition increased the content of copper and cadmium of S. polyrhiza, without causing obvious differences in zinc accumulation under high ambient concentrations. Under high metal conditions, inter-specific competition increased antioxidant enzyme activities in duckweed species, increasing resistance to heavy metals. Results show that inter-specific competition makes duckweed develop mechanisms to increase fitness and survival, such as enhancement of antioxidant enzyme activities, rather than limiting metal uptake when exposed to high concentrations of multiple metals. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in the biological activity of heavy metal- and oil-polluted soils in urban recreation territories

NASA Astrophysics Data System (ADS)

Trifonova, T. A.; Zabelina, O. N.

2017-04-01

Urban recreation areas of different sizes were investigated in the city of Vladimir. The degree of their contamination with heavy metals and oil products was revealed. The content of heavy metals exceeded their maximum permissible concentrations by more than 2.5 times. The total content of heavy metals decreased in the sequence: Zn > Pb > Co > Mn > Cr > Ni. The mass fraction of oil products in the studied soils varied within the range of 0.016-0.28 mg/g. The reaction of soils in public gardens and a boulevard was neutral or close to neutral; in some soil samples, it was weakly alkaline. The top layer of all the soils significantly differed from the lower one by the higher alkalinity promoting the deposition of heavy metals there. As the content of Ni, Co, and Mn increased and exceeded the background concentrations, but did not reach the three-fold value of the maximum permissible concentrations, the activity of catalase was intensified. The stimulating effect of nickel on the catalase activity was mostly pronounced at the neutral soil reaction. The urease activity increased when heavy metals and oil products were present together in the concentrations above the background ones, but not higher than the three-fold maximal permissible concentrations for heavy metals and 0.3 mg/g for the content of oil products. The nitrifying activity was inhibited by oil hydrocarbons that were recorded in the soils in different amounts.

Lauryl Amine as heavy metal collector of boiler ash from pulp and paper mill waste

NASA Astrophysics Data System (ADS)

Sembiring, M. P.; Kaban, J.; Bangun, N.; Saputra, E.

2018-04-01

Theincreasing of demand of pulp and paper products, will following with the growing the pulp and paper industryand generate significant mill waste. The total waste reached 1/3 of the amount raw materials used and ash boiler is the waste with the largest percentage of 52%. For that it takes effort to manage the existing waste. The boiler ash contained the chemical elements, it can be utilized such as fertilizer, because it also contains transition metals in form of heavy metal such as Cadmium (Cd), Cobalt (Co), Chrome (Cr), Cupprum (Cu), Ferrum (Fe), Nickel (Ni), and Zinc (Zn), the use of boiler ash must follow the threshold specified by the Government. Several studies have been undertaken to reduce and extract heavy metals from ash and sand of the boiler by using carbon dioxide as its ligand. Eelectrochemical method was used to remove and recovery of heavy metals from the incenerator. This study focused on removal of heavy metals using Lauryl Amine as collector and three solvents namely Dichloromethane, Ethanol and n-Hexane. The treatmentswas able to extract the heavy metal and generally reduce the heavy metal content of ash boiler pulp and paper mill waste. The combination treatment used toreduce the heavy metal content of 5 gram Lauryl Amine collector in Dichloromethane solvent for 4 hours process time.

Pyrolysis and reutilization of plant residues after phytoremediation of heavy metals contaminated sediments: For heavy metals stabilization and dye adsorption.

PubMed

Gong, Xiaomin; Huang, Danlian; Liu, Yunguo; Zeng, Guangming; Wang, Rongzhong; Wei, Jingjing; Huang, Chao; Xu, Piao; Wan, Jia; Zhang, Chen

2018-04-01

This study aimed to investigate the effect of pyrolysis on the stabilization of heavy metals in plant residues obtained after phytoremediation. Ramie residues, being collected after phytoremediation of metal contaminated sediments, were pyrolyzed at different temperatures (300-700 °C). Results indicated that pyrolysis was effective in the stabilization of Cd, Cr, Zn, Cu, and Pb in ramie residues by converting the acid-soluble fraction of metals into residual form and decreasing the TCLP-leachable metal contents. Meanwhile, the reutilization potential of using the pyrolysis products generated from ramie residues obtained after phytoremediation as sorbents was investigated. Adsorption experiments results revealed that the pyrolysis products presented excellent ability to adsorb methylene blue (MB) with a maximum adsorption capacity of 259.27 mg/g. This study demonstrated that pyrolysis could be used as an efficient alternative method for stabilizing heavy metals in plant residues obtained after phytoremediation, and their pyrolysis products could be reutilized for dye adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

Transformation of heavy metal speciation during sludge drying: mechanistic insights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weng, Huanxin; Ma, Xue-Wen; Fu, Feng-Xia

2014-01-30

Speciation can fundamentally affect on the stability and toxicity of heavy metals in sludge from wastewater treatment plants. This research investigated the speciation of heavy metals in sludge from both municipal and industrial sources, and metal speciation change as a result of drying process to reduce sludge volume. The changes in sludge properties including sludge moisture content, temperature, density, and electrical conductivity were also monitored to provide insights into the mechanisms causing the change in heavy metal speciation. The results show that the drying process generally stabilized the Cr, Cu, Cd and Pb in sludge by transforming acid-soluble, reducible andmore » oxidizable species into structurally stable forms. Such transformation and stabilization occurred regardless of the sludge source and type, and were primarily caused by the changes in sludge properties associated with decomposition of organic matter and sulfide. The results enhanced our understanding of the geochemical behavior of heavy metals in municipal sludge, and are useful for designing a treatment system for environment-friendly disposal of sludge.« less

Transformation of heavy metal speciation during sludge drying: mechanistic insights.

PubMed

Weng, Huan-Xin; Ma, Xue-Wen; Fu, Feng-Xia; Zhang, Jin-Jun; Liu, Zan; Tian, Li-Xun; Liu, Chongxuan

2014-01-30

Speciation can fundamentally affect on the stability and toxicity of heavy metals in sludge from wastewater treatment plants. This research investigated the speciation of heavy metals in sludge from both municipal and industrial sources, and metal speciation change as a result of drying process to reduce sludge volume. The changes in sludge properties including sludge moisture content, temperature, density, and electrical conductivity were also monitored to provide insights into the mechanisms causing the change in heavy metal speciation. The results show that the drying process generally stabilized Cr, Cu, Cd, and Pb in sludge by transforming acid-soluble, reducible, and oxidizable species into structurally stable forms. Such transformation and stabilization occurred regardless of the sludge source and type, and were primarily caused by the changes in sludge properties associated with decomposition of organic matter and sulfide. The results enhanced our understanding of the geochemical behavior of heavy metals in municipal sludge, and are useful for designing a treatment system for environment-friendly disposal of sludge. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

PubMed

Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

2017-01-01

Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

Toxicity of heavy metals and metal-containing nanoparticles on plants.

PubMed

Mustafa, Ghazala; Komatsu, Setsuko

2016-08-01

Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. Copyright © 2016 Elsevier B.V. All rights reserved.

[Leaching characteristics of heavy metals and utilization of filter media in BAF].

PubMed

Zou, Jin-long; Dai, Ying

2007-10-01

A series of leaching tests were conducted to study the solidification of heavy metals in biological filter media made with dried sludge as an additive. The maximum leaching contents of Cd, Cr, Cu and Pb are obtained when pH is 1; leaching contents of heavy metals have an obvious decrease as pH is greater than or equal to 3; and it can be concluded from the results that pH has a significant influence on the leaching characteristic of heavy metals at leaching time of either 24 h or 30 d. X-ray diffraction analysis performed on filter media reveal the main compounds of the 4 heavy metals are Pb2O(CrO4), CdSiO3 and CuO, and the heavy metals are solidified in the mesh structure of Si--O. Heavy metals (such as Cd, Cr, Cu and Pb) can be solidified in filter media through a series of crystalline phase changes and chemical reaction after high temperature sintering. The new filter media (obtained in test) were used in biological aerated filter (BAF) to treat wastewater (C/N about 11.5 and 25.5) in a simultaneous nitrification and denitrification (SND) system. Based on the mechanism of SND, the average removal efficienciesof NH4(+)-N and TN filled with the new filter media (obtained in test) are about 85.5%, 90.3%, 46.6% and 49.6%, respectively, and it is higher than those of other 3 medias (Jiangxi ceramsite, Guangzhou ceramsite and Shanxi activated carbon). The results provide a better understanding of factors that may affect the immobilization and leaching characteristics of heavy metals in ceramsite, which promotes the extensive use of filter media in BAF.

MRP proteins as potential mediators of heavy metal resistance in zebrafish cells.

PubMed

Long, Yong; Li, Qing; Wang, Youhui; Cui, Zongbin

2011-04-01

Acquired resistance of mammalian cells to heavy metals is closely relevant to enhanced expression of several multidrug resistance-associated proteins (MRP), but it remains unclear whether MRP proteins confer resistance to heavy metals in zebrafish. In this study, we obtained zebrafish (Danio rerio) fibroblast-like ZF4 cells with resistance to toxic heavy metals after chronic cadmium exposure and selection for 6months. These cadmium-resistant cells (ZF4-Cd) were maintained in 5μM cadmium and displayed cross-resistance to cadmium, mercury, arsenite and arsenate. ZF4-Cd cells remained the resistance to heavy metals after protracted culture in cadmium-free medium. In comparison with ZF4-WT cells, ZF4-Cd cells exhibited accelerated rate of cadmium excretion, enhanced activity of MRP-like transport, elevated expression of abcc2, abcc4 and mt2 genes, and increased content of cellular GSH. Inhibition of MRP-like transport activity, GSH biosynthesis and GST activity significantly attenuated the resistance of ZF4-Cd cells to heavy metals. The results indicate that some of MRP transporters are involved in the efflux of heavy metals conjugated with cellular GSH and thus play crucial roles in heavy metal detoxification of zebrafish cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Prevalence of exposure of heavy metals and their impact on health consequences.

PubMed

Rehman, Kanwal; Fatima, Fiza; Waheed, Iqra; Akash, Muhammad Sajid Hamid

2018-01-01

Even in the current era of growing technology, the concentration of heavy metals present in drinking water is still not within the recommended limits as set by the regulatory authorities in different countries of the world. Drinking water contaminated with heavy metals namely; arsenic, cadmium, nickel, mercury, chromium, zinc, and lead is becoming a major health concern for public and health care professionals. Occupational exposure to heavy metals is known to occur by the utilization of these metals in various industrial processes and/or contents including color pigments and alloys. However, the predominant source resulting in measurable human exposure to heavy metals is the consumption of contaminated drinking water and the resulting health issues may include cardiovascular disorders, neuronal damage, renal injuries, and risk of cancer and diabetes. The general mechanism involved in heavy metal-induced toxicity is recognized to be the production of reactive oxygen species resulting oxidative damage and health related adverse effects. Thus utilization of heavy metal-contaminated water is resulting in high morbidity and mortality rates all over the world. Thereby, feeling the need to raise the concerns about contribution of different heavy metals in various health related issues, this article has discussed the global contamination of drinking water with heavy metals to assess the health hazards associated with consumption of heavy metal-contaminated water. A relationship between exposure limits and ultimate responses produced as well as the major organs affected have been reviewed. Acute and chronic poisoning symptoms and mechanisms responsible for such toxicities have also been discussed. © 2017 Wiley Periodicals, Inc.

Influence of heavy metal stress on antioxidant status and DNA damage in Urtica dioica.

PubMed

Gjorgieva, Darinka; Kadifkova Panovska, Tatjana; Ruskovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2013-01-01

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity.

Influence of Heavy Metal Stress on Antioxidant Status and DNA Damage in Urtica dioica

PubMed Central

Kadifkova Panovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2013-01-01

Heavy metals have the potential to interact and induce several stress responses in the plants; thus, effects of heavy metal stress on DNA damages and total antioxidants level in Urtica dioica leaves and stems were investigated. The samples are sampled from areas with different metal exposition. Metal content was analyzed by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), for total antioxidants level assessment the Ferric-Reducing Antioxidant Power (FRAP) assay was used, and genomic DNA isolation from frozen plant samples was performed to obtain DNA fingerprints of investigated plant. It was found that heavy metal contents in stems generally changed synchronously with those in leaves of the plant, and extraneous metals led to imbalance of mineral nutrient elements. DNA damages were investigated by Random Amplified Polymorphic DNA (RAPD) technique, and the results demonstrated that the samples exposed to metals yielded a large number of new fragments (total 12) in comparison with the control sample. This study showed that DNA stability is highly affected by metal pollution which was identified by RAPD markers. Results suggested that heavy metal stress influences antioxidant status and also induces DNA damages in U. dioica which may help to understand the mechanisms of metals genotoxicity. PMID:23862140

[Evaluation and cumulative characteristics of heavy metals in soil-Uncaria rhynchophylla system of different functional areas].

PubMed

Zhang, Jia-Chun; Zeng, Xian-Ping; Zhang, Zhen-Ming; Lin, Shao-Xia; Zhang, Qing-Hai; Lin, Chang-Hu

2016-10-01

Soil and Uncaria rhynchophylla in different functional areas were selected for the study,the content of heavy metals such as As, Cd, Cu, Cr, Pb, and Hg in soil and U. rhynchophylla was discussed, the characteristics of their accumulation in the U.rhynchophylla was analyzed, the contamination levels of heavy metals in soil in different functional areas was evaluated. The results showed that content of Cu, As, Pb and Cr in soil was being cropland>woodland>wasteland, content of Cd was being woodland>cropland>wasteland, content of Hg was being cropland>woodland>wasteland. According to quality standard of soil environment, soil Cd in woodland, cropland and wasteland all exceeded the state-level standards, soil Cd in woodland exceeded the secondary standard, soil Hg in cropland and wasteland all exceeded the state-level standards. According to technical conditions of green food producing area, soil Cd in woodland exceeded the limit value of standard. According to Green Trade Standards of Importing Exporting Medicinal Plants Preparations,the content of heavy metals of U.rhynchophylla in cropland,woodland and wasteland were correspond to the specification. From the single factor pollution index, the soil in woodland was polluted by Cd. From the comprehensive pollution index, the soils in different functional areas were not contaminated by heavy metals. The enrichment coefficient of heavy metals such as As, Cu, Cr, and Pb in hook of U.rhynchophylla was being wasteland>woodland>cropland, the enrichment coefficient of Cu in hook of U. rhynchophylla in wasteland was more than 1. Except Cu, the enrichment coefficient of other heavy metals was low. Copyright© by the Chinese Pharmaceutical Association.

[Magnetic Response of Dust-loaded Leaves in Parks of Shanghai to Atmospheric Heavy Metal Pollution].

PubMed

Liu, Fei; Chu, Hui-min; Zheng, Xiang-min

2015-12-01

To reveal the magnetic response to the atmospheric heavy metal pollution in leaves along urban parks, Camphor leaf samples, widely distributed at urban parks, were collected along the year leading wind direction of Shanghai, by setting two vertical and horizontal sections, using rock magnetic properties and heavy metal contents analysis. The results showed that the magnetic minerals of samples were predominated by ferromagnetic minerals, and both the concentration and grain size of magnetite particles gradually decreased with the winter monsoon direction from the main industrial district. A rigorous cleaning of leaves using ultrasonic agitator washer could remove about 63%-90% of low-field susceptibility values of the leaves, and this strongly indicated that the intensity of magnetic signal was mainly controlled by the PMs accumulated on the leaves surfaces. Moreover, there was a significant linear relationship between heavy metals contents (Fe, Mn, Zn, Cu, Cr, V and Pb) and magnetic parameters (0.442 ≤ R ≤ 0.799, P < 0.05), which suggested that magnetic parameters of urban park leaves could be used as a proxy for atmospheric heavy metal pollution. The results of multivariate statistical analysis showed that the content of magnetic minerals and heavy metal indust-loaded tree leaves was affected by associated pollution of industry and traffic.

Environmental risk assessment of radioactivity and heavy metals in soil of Toplica region, South Serbia.

PubMed

Stevanović, Vladica; Gulan, Ljiljana; Milenković, Biljana; Valjarević, Aleksandar; Zeremski, Tijana; Penjišević, Ivana

2018-03-13

Activity levels of natural and artificial radionuclides and content of ten heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and Hg) were investigated in 41 soil samples collected from Toplica region located in the south part of Serbia. Radioactivity was determined by gamma spectrometry using HPGe detector. The obtained mean activity concentrations ± standard deviations of radionuclides 226 Ra, 232 Th, 40 K and 137 Cs were 29.9 ± 9.4, 36.6 ± 11.5, 492 ± 181 and 13.4 ± 18.7 Bq kg -1 , respectively. According to Shapiro-Wilk normality test, activity concentrations of 226 Ra and 232 Th were consistent with normal distribution. External exposure from radioactivity was estimated through dose and radiation risk assessments. Concentrations of heavy metals were measured by using ICP-OES, and their health risks were then determined. Enrichment by heavy metals and pollution level in soils were evaluated using the enrichment factor, the geoaccumulation index (I geo ), pollution index and pollution load index. Based on GIS approach, the spatial distribution maps of radionuclides and heavy metal contents were made. Spearman correlation coefficient was used for correlation analysis between radionuclide activity concentrations and heavy metal contents.

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

PubMed

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

2017-02-01

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

Moisture Influence Reducing Method for Heavy Metals Detection in Plant Materials Using Laser-Induced Breakdown Spectroscopy: A Case Study for Chromium Content Detection in Rice Leaves.

PubMed

Peng, Jiyu; He, Yong; Ye, Lanhan; Shen, Tingting; Liu, Fei; Kong, Wenwen; Liu, Xiaodan; Zhao, Yun

2017-07-18

Fast detection of heavy metals in plant materials is crucial for environmental remediation and ensuring food safety. However, most plant materials contain high moisture content, the influence of which cannot be simply ignored. Hence, we proposed moisture influence reducing method for fast detection of heavy metals using laser-induced breakdown spectroscopy (LIBS). First, we investigated the effect of moisture content on signal intensity, stability, and plasma parameters (temperature and electron density) and determined the main influential factors (experimental parameters F and the change of analyte concentration) on the variations of signal. For chromium content detection, the rice leaves were performed with a quick drying procedure, and two strategies were further used to reduce the effect of moisture content and shot-to-shot fluctuation. An exponential model based on the intensity of background was used to correct the actual element concentration in analyte. Also, the ratio of signal-to-background for univariable calibration and partial least squared regression (PLSR) for multivariable calibration were used to compensate the prediction deviations. The PLSR calibration model obtained the best result, with the correlation coefficient of 0.9669 and root-mean-square error of 4.75 mg/kg in the prediction set. The preliminary results indicated that the proposed method allowed for the detection of heavy metals in plant materials using LIBS, and it could be possibly used for element mapping in future work.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antioxidant modulation in response to heavy metal induced oxidative stress in Cladophora glomerata.

PubMed

Murugan, K; Harish, S R

2007-11-01

The present investigation was carried out to study the induction of oxidative stress subjected to heavy metal environment. Lipoperoxides showed positive correlation at heavy metal accumulation sites indicating the tissue damage resulting from the reactive oxygen species and resulted in unbalance to cellular redox status. The high activities of ascorbate peroxidase and superoxide dismutase probably counter balance this oxidative stress. Glutathione and soluble phenols decreased, whereas dehydroascorbate content increased in the algae from polluted sites. The results suggested that alga responded to heavy metals effectively by antioxidant compounds and scavenging enzymes.

Inventory of heavy metal content in organic waste applied as fertilizer in agriculture: evaluating the risk of transfer into the food chain.

PubMed

Lopes, Carla; Herva, Marta; Franco-Uría, Amaya; Roca, Enrique

2011-07-01

In this work, an environmental risk assessment of reusing organic waste of differing origins and raw materials as agricultural fertilizers was carried out. An inventory of the heavy metal content in different organic wastes (i.e., compost, sludge, or manure) from more than 80 studies at different locations worldwide is presented. The risk analysis was developed by considering the heavy metal (primarily Cd, Cu, Ni, Pb, and Zn) concentrations in different organic residues to assess their potential environmental accumulation and biotransfer to the food chain and humans. A multi-compartment model was used to estimate the fate and distribution of metals in different environmental compartments, and a multi-pathway model was used to predict human exposure. The obtained hazard index for each waste was concerning in many cases, especially in the sludge samples that yielded an average value of 0.64. Among the metals, Zn was the main contributor to total risk in all organic wastes due to its high concentration in the residues and high biotransfer potential. Other more toxic metals, like Cd or Pb, represented a negligible contribution. These results suggest that the Zn content in organic waste should be reduced or more heavily regulated to guarantee the safe management and reuse of waste residues according to the current policies promoted by the European Union.

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

PubMed

Hernández, A J; Pastor, J

2008-04-01

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

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.

Mannosomes: a molluscan intracellular tubular membrane system related to heavy metal stress?

PubMed

Knigge, Thomas; Mann, Neelam; Parveen, Zahida; Perry, Christopher; Gernhöfer, Maike; Triebskorn, Rita; Köhler, Heinz R; Connock, Martin

2002-03-01

Amongst animals, several hydrogen peroxide-generating oxidases are apparently restricted to molluscs. One of these, D-mannitol oxidase, is concentrated in the alimentary system, where it is associated with its own subcellular membrane system of unique tubular morphology, most likely representing a structural modification of the ER. These structures can be purified by subcellular fractionation and have been termed 'mannosomes'. Little is known about the functions of mannitol oxidase or of mannosomes, but the previously reported molluscicide-induced increase in mannosomes implies their involvement in a general stress reaction. In this study, we examined the effects of heavy metal stress in the terrestrial gastropod Arion lusitanicus. The activity of mannitol oxidase and mannosome abundance were monitored, together with metal effects on heat-shock protein level, and these parameters were compared to heavy metal accumulation in the digestive gland. We found that mannitol oxidase is inhibited by heavy metals more than other oxidases. On the other hand, hsp70 levels and mannosomal protein were increased with enhanced heavy metal stress, the latter indicating a probable increase in the number of mannosome organelles. Thus, stress protein (hsp70) and mannosomal protein were positively correlated with heavy metal accumulation, whereas the enzyme activity showed a negative correlation with increasing heavy metal content of the slugs.

Bioaccumulation of heavy metals in crop plants grown near Almeda Textile Factory, Adwa, Ethiopia.

PubMed

Gitet, Hintsa; Hilawie, Masho; Muuz, Mehari; Weldegebriel, Yirgaalem; Gebremichael, Dawit; Gebremedhin, Desta

2016-09-01

The contents of heavy metals cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) present in water (wastewater and wetland), soils, and food crops collected from the vicinity of Almeda Textile Factory were quantified using Flame Atomic Absorption Spectrometer (FAAS) in order to assess the environmental impact of the textile factory. The contents of heavy metals determined in the wastewater were found below the recommended limit set by WHO and United States Environmental Protection Agency (US EPA) except for Cr, which was found slightly higher than WHO permissible limit. Besides, the contents of the heavy metals determined in soils were below the permissible level of FAO/WHO and Canada maximum allowable limits. Moreover, only the concentrations of Cd and Pb were found above the permissible level set by FAO/WHO in the crop plants studied. Generally, the mean concentrations of heavy metals in the plants were in the decreasing order of: Mn > Zn > Cu > Pb > Ni > Co > Cr > Cd. Nevertheless, higher bioconcentration factor (BCF) was found for Cd (0.108-1.156) followed by Zn (0.081-0.499). In conclusion, comparison of heavy metal concentrations with the permissible limits in all collected sample types i.e. water, soil, and crop plants did not show significant pollution from the factory.

Blackberry wines mineral and heavy metal content determination after dry ashing: multivariate data analysis as a tool for fruit wine quality control.

PubMed

Amidžić Klarić, Daniela; Klarić, Ilija; Mornar, Ana; Velić, Darko; Velić, Natalija

2015-08-01

This study brings out the data on the content of 21 mineral and heavy metal in 15 blackberry wines made of conventionally and organically grown blackberries. The objective of this study was to classify the blackberry wine samples based on their mineral composition and the applied cultivation method of the starting raw material by using chemometric analysis. The metal content of Croatian blackberry wine samples was determined by AAS after dry ashing. The comparison between an organic and conventional group of investigated blackberry wines showed statistically significant difference in concentrations of Si and Li, where the organic group contained higher concentrations of these compounds. According to multivariate data analysis, the model based on the original metal content data set finally included seven original variables (K, Fe, Mn, Cu, Ba, Cd and Cr) and gave a satisfactory separation of two applied cultivation methods of the starting raw material.

Application of Heavy Metal Rich Tannery Sludge on Sustainable Growth, Yield and Metal Accumulation by Clarysage (Salvia sclarea L.).

PubMed

Chand, Sukhmal; Yaseen, M; Rajkumari; Patra, D D

2015-01-01

A field experiment was conducted to evaluate the effective utilization of tannery sludge for cultivation of clarysage (Salvia sclarea) at CIMAP research farm, Lucknow, India during the year 2012-2013. Six doses (0, 20, 40, 60, 80, 100 tha(-1)) of processed tannery sludge were tested in randomised block design with four replications. Results revealed that maximum shoot, root, dry matter and oil yield were obtained with application of 80 tha(-1)of tannery sludge and these were 94, 113 and 61% higher respectively, over control. Accumulation of heavy metals (Cr, Ni, Fe, Pb) were relatively high in shoot portion of the plant than root. Among heavy metals, magnitude of chromium accumulation was higher than nickel, iron and lead in shoot as well as in root. Linalool, linalyl acetate and sclareol content in oil increased by 13,8 and 27% respectively over control, with tannery sludge application at 80 tha(-1). Heavy metals such as chromium, cadmium and lead content reduced in postharvest soil when compared to initial status. Results indicated that clarysage (Salvia sclarea) can be grown in soil amended with 80 tha(-1)sludge and this can be a suitable accumulator of heavy metals for phytoremediation of metal polluted soils.

Assessment of different methods to estimate heavy metal bioavailability in 30 contrasting Spanish and New Zealand soils

NASA Astrophysics Data System (ADS)

Soriano-Disla, J. M.; Speir, T. W.; Gómez, I.; Clucas, L. M.; McLaren, R. G.; Navarro-Pedreño, J.

2009-04-01

The accumulation of heavy metals in soil from different sources (atmospheric deposition, agricultural practices, urban-industrial activities, etc.) is of a great environmental concern because of metal persistence and toxicity. In this sense, there is a consensus in the literature that the estimation of the bioavailable heavy metals in soil is a preferable tool to determine potential risks from soil contamination than the total contents. However, controversy exists around the definition of an accurate and universal bioavailability estimator that is useful for soils with different properties, since many factors control this parameter. Thus, the main objective of this work was to compare the effectiveness of different methods to predict heavy metals plant uptake from soils with different properties and heavy metal contents. For the development of the present work, 30 contrasting soils from New Zealand and Spain were selected. Apart from the analysis of the basic soil properties, different methods to estimate heavy metal bioavailability were performed: total heavy metals, DTPA-extractable soil metals, diffusive gradient technique (DGT), and total heavy metals in soil solution. In these soils, a bioassay using wheat (Triticum aestivum) was carried out in a constant environment room for 25 days (12 hours photoperiod, day and night temperature of 20°C and 15°C respectively). After this time, the plants were divided in roots and shoots and heavy metal content was analysed in each part. Simple correlations were performed comparing the phytoavailable contents with the bioavailability estimated by the different methods. As expected, higher heavy metal concentrations were found in roots compared with shoots. Comparing the theoretical available heavy metals estimated by the different methods with the root and shoot uptake, better correlations were found with the root contents, thus, the discussion is based in the comparisons with the uptake by this part of the plant

Heavy metal anomalies in the Tinto and Odiel River and estuary system, Spain

USGS Publications Warehouse

Nelson, C.H.; Lamothe, P.J.

1993-01-01

The Tinto and Odiel rivers drain 100 km from the Rio Tinto sulphide mining district, and join at a 20-km long estuary entering the Atlantic Ocean. A reconnaissance study of heavy metal anomalies in channel sand and overbank mud of the river and estuary by semi-quantitative emission dc-arc spectrographic analysis shows the following upstream to downstream ranges in ppm (??g g-1): As 3,000 to <200, Cd 30 to <0.1, Cu 1,500 to 10, Pb 2,000 to <10, Sb 3000 to <150, and Zn 3,000 to <200. Organic-rich (1.3-2.6% total organic carbon, TOC), sandysilty overbank clay has been analyzed to represent suspended load materials. The high content of heavy metals in the overbank clay throughout the river and estuary systems indicates the importance of suspended sediment transport for dispersing heavy metals from natural erosion and anthropogenic mining activities of the sulfide deposit. The organic-poor (0.21-0.37% TOC) river bed sand has been analyzed to represent bedload transport of naturally-occurring sulfide minerals. The sand has high concentrations of metals upstream but these decrease an order of magnitude in the lower estuary. Although heavy metal contamination of estuary mouth beach sand has been diluted to background levels estuary mud exhibits increased contamination apparently related to finer grain size, higher organic carbon content, precipitation of river-borne dissolved solids, and input of anthropogenic heavy metals from industrial sources. The contaminated estuary mud disperses to the inner shelf mud belt and offshore suspended sediment, which exhibit metal anomalies from natural erosion and mining of upstream Rio Tinto sulphide lode sources (Pb, Cu, Zn) and industrial activities within the estuary (Fe, Cr, Ti). Because heavy metal contamination of Tinto-Odiel river sediment reaches or exceeds the highest levels encountered in other river sediments of Spain and Europe, a detailed analysis of metals in water and suspended sediment throughout the system, and

Assessment of heavy metals in Averrhoa bilimbi and A. carambola fruit samples at two developmental stages.

PubMed

Soumya, S L; Nair, Bindu R

2016-05-01

Though the fruits of Averrhoa bilimbi and A. carambola are economically and medicinally important, they remain underutilized. The present study reports heavy metal quantitation in the fruit samples of A. bilimbi and A. carambola (Oxalidaceae), collected at two stages of maturity. Heavy metals are known to interfere with the functioning of vital cellular components. Although toxic, some elements are considered essential for human health, in trace quantities. Heavy metals such as Cr, Mn, Co, Cu, Zn, As, Se, Pb, and Cd were analyzed by atomic absorption spectroscopy (AAS). The samples under investigation included, A. bilimbi unripe (BU) and ripe (BR), A. carambola sour unripe (CSU) and ripe (CSR), and A. carambola sweet unripe (CTU) and ripe (CTR). Heavy metal analysis showed that relatively higher level of heavy metals was present in BR samples compared to the rest of the samples. The highest amount of As and Se were recorded in BU samples while Mn content was highest in CSU samples and Co in CSR. Least amounts of Cr, Zn, Se, Cd, and Pb were noted in CTU while, Mn, Cu, and As were least in CTR. Thus, the sweet types of A. carambola (CTU, CTR) had comparatively lower heavy metal content. There appears to be no reason for concern since different fruit samples of Averrhoa studied presently showed the presence of various heavy metals in trace quantities.

Biomolecules for Removal of Heavy Metal.

PubMed

Singh, Namita Ashish

2017-01-01

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

Heavy metal pollution among autoworkers. II. Cadmium, chromium, copper, manganese, and nickel.

PubMed Central

Clausen, J; Rastogi, S C

1977-01-01

Garages and auto-repair workshops may be polluted with other heavy metals besides lead. Blood of autoworkers with high lead content was analysed for cadmium, chromium, copper manganese, nickel, ALAD activity and carboxyhaemoglobin level. Cadmium and copper levels in blood of autoworkers were comparable with those of the control subjects while chroimium and nickel levels were significantly higher (P less than 0-01 for both metals), and scattered raised values of manganese were found. There was no significant mutual correlation between levels of various heavy metals determined in whole blood. High copper levels were slightly related to decreasing ALAD activity (P less than 0-1). Nineteen per cent of autoworkers were found to have an abnormally blood level of carboxyhaemoglobin. The amount of particulate heavy metal in autoworkshop air was not related to biochemical abnormalities found in the autoworkers. Various sources of pollution of these heavy metals in autoworkshops are discussed. PMID:71915

Reduction of heavy metals in residues from the dismantling of waste electrical and electronic equipment before incineration.

PubMed

Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Hu, Li-Fang; Shen, Dong-Sheng

2014-05-15

Residues disposal from the dismantling of waste electrical and electronic equipment are challenging because of the large waste volumes, degradation-resistance, low density and high heavy metal content. Incineration is advantageous for treating these residues but high heavy metal contents may exist in incinerator input and output streams. We have developed and studied a specialized heavy metal reduction process, which includes sieving and washing for treating residues before incineration. The preferable screen aperture for sieving was found to be 2.36mm (8 meshes) in this study; using this screen aperture resulted in the removal of approximately 47.2% Cu, 65.9% Zn, 26.5% Pb, 55.4% Ni and 58.8% Cd from the residues. Subsequent washing further reduces the heavy metal content in the residues larger than 2.36mm, with preferable conditions being 400rpm rotation speed, 5min washing duration and liquid-to-solid ratio of 25:1. The highest cumulative removal efficiencies of Cu, Zn, Pb, Ni and Cd after sieving and washing reached 81.1%, 61.4%, 75.8%, 97.2% and 72.7%, respectively. The combined sieving and washing process is environmentally friendly, can be used for the removal of heavy metals from the residues and has benefits in terms of heavy metal recycling. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Speciation of heavy metals in landfill leachate: a review.

PubMed

Baun, Dorthe L; Christensen, Thomas H

2004-02-01

The literature was reviewed with respect to metal speciation methods in aquatic samples specifically emphasizing speciation of heavy metals in landfill leachate. Speciation here refers to physical fractionation (particulate, colloidal, dissolved), chemical fractionation (organic complexes, inorganic complexes, free metal ions), as well as computer-based thermodynamic models. Relatively few landfill leachate samples have been speciated in detail (less than 30) representing only a few landfills (less than 15). This suggests that our knowledge about metal species in landfill leachate still is indicative. In spite of the limited database and the different definitions of the dissolved fraction (< 0.45 microm or < 0.001 microm) the studies consistently show that colloids as well as organic and inorganic complexes are important for all heavy metals in landfill leachate. The free metal ion constitutes less than 30%, typically less than 10%, of the total metal concentration. This has significant implications for sampling, since no standardized procedures exist, and for assessing the content of metals in leachate in the context of its treatment, toxicity and migration in aquifers.

[MONITORING OF THE CONTENT OF HEAVY METALS AND ELEMENTS IN THE SNOW COVER IN AGRICULTURAL SOILS AT THE TERRITORY OF THE MOSCOW REGION].

PubMed

Ermakov, A A; Karpova, E A; Malysheva, A G; Mikhaylova, R I; Ryzhova, I N

2015-01-01

The monitoring of snow cover pollution by heavy metals and elements (zinc, copper, lead, cadmium, arsenic, nickel, chromium, strontium, manganese, fluorine, lithium) was performed in 20 districts of the Moscow region in 2009, 2012 and 2013. The assessment of the levels of contamination by heavy metals and elements was given by means of comparison of them with the average values in the snow cover near Moscow in the end of the last century and in some areas of the world, that no exposed to technological environmental impact. 7 districts of Moscow region were characterized by a high content of lead and cadmium in the snow water. It requires the control of water, soil and agricultural products pollution.

Phytoavailability of Cd and Pb in crop straw biochar-amended soil is related to the heavy metal content of both biochar and soil.

PubMed

Shen, Xin; Huang, Dao-You; Ren, Xue-Fei; Zhu, Han-Hua; Wang, Shuai; Xu, Chao; He, Yan-Bing; Luo, Zun-Chang; Zhu, Qi-Hong

2016-03-01

Crop straw biochar incorporation may be a sustainable method of amending soil, but feedstock-related Cd and Pb content is a major concern. We investigated the effects of heavy metal-rich (RC) and -free biochar (FC) on the phytoavailability of Cd and Pb in two acidic metalliferous soils. Biochar significantly increased soil pH and improved plant growth. Pb in soil and plant tissues significantly decreased after biochar application, and a similar pattern was observed for Cd after FC application. RC significantly increased NH4NO3-extractable Cd in both lightly contaminated (YBS) and heavily contaminated soils (RS). The Cd content of plants grown on YBS increased, whereas it decreased on RS. The Cd and Pb input-output balance suggested that RC application to YBS might induce a soil Cd accumulation risk. Therefore, identifying heavy metal contamination in biochar is crucial before it is used as a soil amendment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Heavy metal pollution status and ecological risks of sediments under the influence of water transfers in Taihu Lake, China.

PubMed

Liu, Jiajia; Wang, Peifang; Wang, Chao; Qian, Jin; Hou, Jun

2017-01-01

The effects of water transfer projects on water channels and the receiving water involved need to be understood. In this research, the compositions and particle size distributions of surface sediment and the Cd, Cr, Cu, Ni, Pb, and Zn contents and distributions in the sediment along a water transfer route from the Wangyu River to Taihu Lake, China, were studied. The correlative relationship between the grain size trend and heavy metal content distribution suggested that heavy metals in Wangyu River sediment have affected the heavy metal contents of Taihu Lake sediment through silt and clay migrating in the transferred water. Enrichment factors and potential ecological risk values were calculated. Low levels of potential ecological risks are posed at 20 sampling sites in Taihu Lake, but higher-to-serious risks (potential ecological risk values >275) are posed at all Wangyu River sites. Toxicity of heavy metals (Cd, Cu, Zn, and Ni) in the Wangyu River sediments is more serious than those in the Taihu Lake, but is similar to the entrance of Gonghu Bay. Multivariate statistical analyses (Pearson correlation, cluster, and factor analyses) suggested heavy metals in the study area have many sources, and the relationships between particle migration and heavy metal contents indicated transferring water are likely to lead to adverse ecological risks being posed in Taihu Lake.

Characteristics of tree bark as an indicator in high-immission areas : II. Contents of heavy metals.

PubMed

Lötschert, W; Köhm, H -J

1978-01-01

1. Studies on indicator characteristics of bark of deciduous trees have been continued by measuring accumulation of Pb, Cd, Ni and Mn in the bark of Fraxinus excelsior at 34 sampling sites over an area of 150 km 2 in the immission area of Frankfurt am Main. 2. Iso-lines of equal Pb-contamination have been found. They include zones of graduated immissions. The pattern of these zones shows an eccentrical orientation and is the result of the distribution of the main traffic roads. A significant correlation of Pb in the bark and traffic congestion has been found. 3. The zones of Cd-contamination stretch from SW to NE. The orientation of these zones is determined by the distribution of the big emittenrs and the centers of heating power in the area and the predominating direction of wind. 4. A correlation between the accumulation of Pb and Cd has been detected. It is less significant than that between pH-value and sulfur content in the bark of trees in former investigations. 5. The distribution of Pb and Mn is antagonistic in the bark of Fraxinus excelsior and parallel in the needles of Taxus baccata. The content of Mn in the bark of Fraxinus is low. It must be accepted that this is partly an effect of elution by sulfur acid-aerosol formation. 6. The strongest accumulation of heavy metal immissions is found in mosses on the ground, mainly in Bryum argenteum. Nevertheless the bark of Fraxinus excelsior has shown consequently its accumulation characteristics as a good immission indicator for heavy metal contaminations by traffic and big emittents.

Heavy Metal Contaminated Soil Imitation Biological Treatment Overview

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Process for removing heavy metal compounds from heavy crude oil

DOEpatents

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

1991-01-01

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

Granulometric selectivity in Liza ramado and potential contamination resulting from heavy metal load in feeding areas

NASA Astrophysics Data System (ADS)

Pedro, Sílvia; Canastreiro, Vera; Caçador, Isabel; Pereira, Eduarda; Duarte, Armando C.; Raposo de Almeida, Pedro

2008-11-01

The stomach contents of thin-lipped grey mullets Liza ramado were analysed in terms of granulometric composition and compared to the sediment of potential feeding areas in the Tagus estuary. Total organic matter (TOM) content and heavy metal content were determined in the surface sediment of three areas and eight trace elements were quantified: Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. The three sampled areas did not differ in TOM; and the heavy metal content was below Effects Range-Low level for most elements. The mean observed concentrations were present in the following sequence: Zn > Pb > Cr > Cu ≈ Ni > Co > Cd > Hg. Stomach contents granulometric composition provided information about the feeding selectivity of the mullets. Sediment fractions with particle size between 20 and 50 μm are preferred, independently of the fishes' length. Smaller standard length (SL) fishes have a higher positive selection of fine grained sediments than those with a larger SL. Finer fractions usually have higher concentration of heavy metals, which makes younger specimens of the thin-lipped grey mullet potentially more exposed to heavy metal load in the estuary. Metal concentration was not independent from the sampling point, presenting higher values near the margins and the estuary tidal drainage system. This means that during the first period of each tidal cycle, the mullets will feed first on the most contaminated areas, as a consequence of their movement following the rising tide to feed on previously exposed areas.

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

PubMed

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

2018-01-01

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

Contents and risk assessment of heavy metals in marine invertebrates from Korean coastal fish markets.

PubMed

Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kang, Sung Rim; Ha, Na Young; Jo, Mi Ra; Kim, Ji Hoe

2014-06-01

The concentrations of the heavy metals cadmium (Cd), mercury (Hg), lead (Pb), chromium, silver, nickel, copper, and zinc in the edible portions of 105 marine invertebrates representing 16 mollusk and crustacean species were accurately determined to evaluate their hazard for human consumption. The samples were collected in 2011 from major fish markets on the coast of Korea and analyzed for Hg using a direct Hg analyzer and for other metals using inductively coupled plasma mass spectrometry. Estimated dietary exposure (EDE) was determined, and a risk assessment was made of the heavy metals to provide information concerning consumer safety. The Cd concentrations, which were the highest for the three hazardous metals (Cd, Hg, and Pb), were significantly higher (P < 0.05) in the bivalves and crabs than in the gastropods and cephalopods. However, the concentrations of these metals in all samples were within the regulatory limits set by Korea and other countries. The EDE was compared with the provisional tolerable daily intake (PTDI) adopted by the Joint FAO/WHO Expert Committee on Food Additives or the U.S. Environmental Protection Agency. The EDE of Cd, Hg, and Pb for each class of marine invertebrate were 0.07 to 2.64, 0.01 to 0.43, and 0.001 to 0.16% of the PTDI, respectively. The total EDE of Cd, Hg, and Pb for marine invertebrates accounted for 4.03, 0.96, and 0.21%, respectively, of the PTDI. The EDE of other metals in each class of marine invertebrate was less than 2% of the PTDI. The hazard index is a reasonable parameter for assessing the risk of heavy metal consumption associated with contaminated food. In the present study, the hazard index for all of the species was less than 1.0, which indicates that the intake of heavy metals from consumption of these marine invertebrates does not represent an appreciable hazard to humans.

Simultaneous decontamination of cross-polluted soils with heavy metals and PCBs using a nano-metallic Ca/CaO dispersion mixture.

PubMed

Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

2014-01-01

In the present work, we investigated the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the simultaneous remediation of contaminated soils with both heavy metals (As, Cd, Cr, and Pb) and polychlorinated biphenyls (PCBs). Regardless of soil moisture content, nano-metallic Ca/CaO dispersion mixture achieved about 95-99% of heavy metal immobilization by a simple grinding process. During the same treatment, reasonable PCB hydrodechlorination efficiencies were obtained (up to 97%), though higher hydrodechlorination efficiency by preliminary drying of soil was observed.

Distributions of Heavy Metals and Benzo[ a]pyrene in Oligotrophic Peat Soils and Peat Gleyzems of Northeastern Sakhalin

NASA Astrophysics Data System (ADS)

Lipatov, D. N.; Shcheglov, A. I.; Manakhov, D. V.; Karpukhin, M. M.; Zavgorodnyaya, Yu. A.; Tsvetnova, O. B.

2018-05-01

The contents and profile distributions of Cr, Ni, Cu, Zn, Cd, Hg, Pb, and benzo[a]pyrene in oligotrophic peat soils, oligotrophic peat gley soils (Dystric Fibric Histosols), humus-impregnated peat gleyzems (Dystric Histic Gleysols), and mucky gleyzems (Dystric Gleysols) have been analyzed with consideration for their degree of oligotrophicity and anthropogenic loads. Horizons with the accumulation (O, Tpyr, TT) and removal (Ghi,e) of heavy metals have been revealed. The increase in the content of heavy metals and benzo[ a]pyrene in the upper layer of oligotrophic peat soils under technogenic fallouts in the impact zone of flare and motor transport has been considered. Statistical parameters of the spatial variation of parameters in organic and gley horizons have been calculated. The variation coefficients of pollutant elements (Pb and Zn) in the surface horizons of soils increase to 100-125%. Positive correlations revealed between the content of some heavy metals in litter indicate their bioaccumulation and possible joint input with aerotechnogenic fallouts. No correlations are found between the contents of benzo[ a]pyrene and heavy metals, but a reliable negative correlation with the ash content is noted in the peat horizon.

Geochemical characteristics of Heavy metals of river sediment from the main rivers at Texas, USA.

NASA Astrophysics Data System (ADS)

Matsumoto, I.; Hoffman, D.; MacAlister, J.; Ishiga, H.

2008-12-01

Trinity River is one of the biggest rivers which flows through Dallas and Fort Worth two big cities of USA and are highly populated. Trinity river drains into the Gulf of Mexico. Sediment samples collected from various points along the upper and lower streams were subjected to content analysis and elution analysis (using liquate (flow) out test) on the heavy metals like Cd, CN, Pb, Cr, As, Hg, Ni, Zn and Cu from the river sediment for the purpose of environment assessment. A total of 22 sample points were identified from upper stream to lower stream and samples were collected such that almost the whole stream length of Trinity River is covered. Results show that heavy metal content through out the river stream is below the recommended limits posing no immediate environmental threat. However, the experimental results show clear impact of human population in bigger cities on heavy metal concentrations in the river sediments as compared to smaller cities with low human population. It could be seen from the analysis that all the heavy metals show relatively high content and high elution value in Dallas and Fort Worth. As we move away from the big cities, the value of content and elution of sediment decreased by natural dilution effect by the river. And we also present the data of the Colorado and San Antonio rivers.

Cytoplasmic inorganic polyphosphate participates in the heavy metal tolerance of Cryptococcus humicola.

PubMed

Andreeva, Nadezhda; Ryazanova, Lubov; Dmitriev, Vladimir; Kulakovskaya, Tatiana; Kulaev, Igor

2014-09-01

The basidiomycetous yeast Cryptococcus humicola was shown to be tolerant to manganese, cobalt, nickel, zinc, lanthanum, and cadmium cations at a concentration of 2.5 mmol/L, which is toxic for many yeasts. The basidiomycetous yeast Cryptococcus terreus was sensitive to all these ions and did not grow at the above concentration. In the presence of heavy metal cations, С. humicola, as opposed to C. terreus, was characterized by the higher content of acid-soluble inorganic polyphosphates. In vivo 4',6'-diamino-2-phenylindole dihydrochloride staining revealed polyphosphate accumulation in the cell wall and cytoplasmic inclusions of С. humicola in the presence of heavy metals. In C. terreus, polyphosphates in the presence of heavy metals accumulate mainly in vacuoles, which results in morphological changes in these organelles and, probably, disturbance of their function. The role of polyphosphate accumulation and cellular localization as factors of heavy metal tolerance of Cryptococcus humicola is discussed.

[Biochemical protective mechanisms in the accumulation of heavy metals in organisms].

PubMed

Petukhov, A S; Petukhova, G A

At present due to the environmental contamination by heavy metals there is a great interest to investigate the processes of their both accumulation in plants and toxic effect on biochemical indices. Therefore the objective of this research was the analysis of the alteration of the system of antioxidant protection ofplants in conditions of soil contamination by copper and zinc. Research object were germinants of oat in amount of300 plants in each variant of the experiment. For the performance of the experiment, the sand was equally contaminated by sulfates of Cu and Zn in concentration of 2 MPC on its gross content in soil. The experiment lastedfor 2 weeks. For the implementation of the objective of research there was analyzed the contentof both Cu and Zn in plants exposed to soil contamination. Additionally there was performed an analysis of as the content of lipids peroxidation products, phenols and flavonoids; as well the activity ofperoxidase, catalase and photosynthetic system. Under the soil contamination by copper and zinc corresponding to 2 MPC the accumulation of heavy metals was established to be happening in plants. If compared copper accumulation was higher than zinc accumulation that can be explained by the high migration capability of zinc. Under combined impact of two metals there was revealed their antagonistic interaction. There was established an elevated content of lipids peroxidation products in cells as a sequence of the accumulation of heavy metals in plants. As a result of the elevation of the content of lipids peroxidation products there was revealed a raised activity ofphotosynthetic apparatus and antioxidant system (carotenoids, catalase and peroxidase) in the cell. The decrease of the content ofphenols and flavonoids is related with the usage of this system of antioxidant protection for the neutralization of lipids peroxidation processes.

[Pollution distribution and potential ecological risk assessment of heavy metals in sediments from the different eastern dredging regions of Lake Taihu].

PubMed

Mao, Zhi-Gang; Gu, Xiao-Hong; Lu, Xiao-Ming; Zeng, Qing-Fei; Gu, Xian-Kun; Li, Xu-Guang

2014-01-01

In order to investigate the distribution characteristics of nutrients and heavy metals in sediments from different eastern dredging regions of Lake Taihu, the surface and core sediment samples at 5 sites (in East Taihu Lake and Xukou Bay) were collected in 2012. Contents of nutrients (TOC, TN and TP) and heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments were measured and the pollution degrees of heavy metals were evaluated with the potential ecological risk method. The results showed that the heavy metal contents in Xukou Bay were generally higher than those in East Taihu Lake, whereas the nutrients contents showed the reverse trend. There were significant differences between the phytoplankton-dominated and culture lake regions. The concentrations of both nutrients and heavy metals decreased with increasing profile depth. Moreover, the contents of nutrients and heavy metals in the sediments of all dredged areas were lower than those in the un-dredged areas, suggesting that dredging may be a useful approach for decreasing nutrients and heavy metals loading in sediments, but its effectiveness decreased with time. Significant positive correlations were found among different heavy metals and nutrients, indicating that they were from the same pollution source. The Hakanson potential ecological risk index was applied for assessing the status of sediment heavy metal enrichment and the result indicated that sediment dredging could reduce the extent of potential ecological risk. The risk index in different sites followed the order: X1 > D1 > D3 > X2 > D2, while the risk index in site X1 of Xukou Bay was higher than that in site D1 of East Taihu Lake. And the comprehensive ecological risk grades in sites X1 and D1 were in the moderate range, while the sites D2, D3 and X2 were low.

Evaluation of heavy metals and polycyclic aromatic hydrocarbons in honeys from different origins.

PubMed

Corredera, Lourdes; Bayarri, Susana; Pérez-Arquillué, Consuelo; Lázaro, Regina; Molino, Francisco; Herrera, Antonio

2014-03-01

A survey of honey samples from different geographical and botanical origins, including some samples collected from a fire-affected area in Spain, was conducted to assess their content of heavy metals and polycyclic aromatic hydrocarbons (PAHs). The levels of the determined toxic elements (Pb, Cd, As, and Sn) were low and were in the range of those reported by other studies. In our work the total amount of heavy metals and Pb was higher in dark honeys than in pale honeys. In the collected samples, no detectable levels of the 15 PAHs studied were found. The obtained data served to assess the levels of heavy metals and PAHs in honey samples from different geographical and environmental origins and to contribute to the scarce data about pollutant content of this matrix. In light of these results, the analyzed samples do not pose any serious concern to human health, and the data obtained in this study could serve to contribute to the establishment of specific maximum limits for honey.

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.

[Spatial distribution and ecological risk assessment of heavy metals in the estuaries surface sediments from the Haihe River Basin].

PubMed

Lü, Shu-Cong; Zhang, Hong; Shan, Bao-Qing; Li, Li-Qing

2013-11-01

It is well known that the rivers in the Haihe River Basin have been seriously polluted. However, what is the present condition of the estuary pollution and how the polluted inland rivers affect the estuary areas are not clear. 10 main estuaries of the Haihe River Basin were selected to measure the contents of typical heavy metals (Pb, Cu, Zn, Cd, Cr and Ni) in the surface sediments and to analyze the spatial distribution of these heavy metals. The potential ecological risk index was used to assess the ecological risk of the six heavy metals in the estuaries. The results showed that the contents of Pb, Cu, Zn, Cd, Cr and Ni in the surface sediments of the 10 estuaries were all higher than their background values in the main local soil types and the contents of Cu, Ni and Pb were 2.3-2.6 times as high as their background values, which indicated that the estuaries were contaminated by the six heavy metals. The results also indicated that the contents of the six heavy metals in surface sediment varied from one estuary to another. The four heavy metals of Cr, Cu, Ni and Zn had bigger spatial differences than Pb and Cd in the contents in sediment from different estuaries. The contents of Cr, Cu, Ni and Zn in sediment were higher in the estuaries of the Yongdingxin River, Ziyaxin River and Beipai River than those in the other estuaries, and there were significant correlations between each other (R(Cu-Zn) = 0.891, R(Cu-Cr) = 0.927, R(Cu-Ni) = 0.964, R(Zn-Cr) = 0.842, R(Zn-Ni) = 0.939, and R(Cr-Ni) = 0.879, P < 0.01), which indicated that they possibly came from the same sources. Moreover, the contents of Cr, Cu, Ni and Zn in sediment also had significant correlations with the populations of sub-river basins with correlation coefficients of 0.855, 0.806, 0.867 and 0.855 (P < 0.01), respectively. The contents of Cd and Pb had smaller spatial differences in sediment from different estuaries than the other heavy metals, with the values ranged 23.3-95.8 mg x kg(-1) and 0

Noninvasive evaluation of heavy metal uptake and storage in micoralgae using a fluorescence resonance energy transfer-based heavy metal biosensor.

PubMed

Rajamani, Sathish; Torres, Moacir; Falcao, Vanessa; Ewalt Gray, Jaime; Coury, Daniel A; Colepicolo, Pio; Sayre, Richard

2014-02-01

We have developed a fluorescence resonance energy transfer (FRET)-based heavy metal biosensor for the quantification of bioavailable free heavy metals in the cytoplasm of the microalga Chlamydomonas reinhardtii. The biosensor is composed of an end-to-end fusion of cyan fluorescent protein (CFP), chicken metallothionein II (MT-II), and yellow fluorescent protein (YFP). In vitro measurements of YFP/CFP fluorescence emission ratios indicated that the addition of metals to the purified biosensor enhanced FRET between CFP and YFP, consistent with heavy metal-induced folding of MT-II. A maximum YFP/CFP FRET ratio of 2.8 was observed in the presence of saturating concentrations of heavy metals. The sensitivity of the biosensor was greatest for Hg2+ followed by Cd2+≈Pb2+>Zn2+>Cu2+. The heavy metal biosensor was unresponsive to metals that do not bind to MT-II (Na+ and Mg2+). When expressed in C. reinhardtii, we observed a differential metal-dependent response to saturating external concentrations (1.6 mm) of heavy metals (Pb2+>Cd2+) that was unlike that observed for the isolated biosensor (in vitro). Significantly, analysis of metal uptake kinetics indicated that equilibration of the cytoplasm with externally applied heavy metals occurred within seconds. Our results also indicated that algae have substantial buffering capacity for free heavy metals in their cytosol, even at high external metal concentrations.

Mathematical modelling for distribution of heavy metals in estuary area of Red River (Vietnam)

NASA Astrophysics Data System (ADS)

Nguyen, N. T. T.; Volkova, I. V.

2018-05-01

In this paper, the authors studied the features of spatial distribution of some heavy metals (Pb, Hg, As) in the system “suspended substance - bottom sediments” in the mouth area of the Red River (Vietnam). A mathematical modelling for diffusion processes of heavy metals in a suspended form, in bottom sediments and the spatial analysis for the results of these models were proposed and implemented. The studies were carried out during main hydrological seasons of 2014 - 2016 (during the flood and inter-natal periods). The propagation of heavy metals was modeled by solving the equation of turbulent diffusion. A spatial analysis of the content of heavy metals in the suspended form and in the bottom sediments was implemented by using the interpolation model in ArcGIS 10.2.2. The distribution of Pb, Hg, As concentration of the suspended form and bottom sediment phases in the estuary area of the Red River was characterized by maximum in the mouths of the branches and general decreasing gradient towards the sea. Maximum concentrations of Pb, Hg in suspended forms were observed in the surface layer of water at the river-sea barrier. The content of Hg and As in the estuary region of the Red River was observed in the following order: SSsurf< SSbott< BS; and content of Pb – SS >BS.

[Effects of stabilization treatment on migration and transformation of heavy metals in mineral waste residues].

PubMed

Zhao, Shu-Hua; Chen, Zhi-Liang; Zhang, Tai-Ping; Pan, Wei-Bin; Peng, Xiao-Chun; Che, Rong; Ou, Ying-Juan; Lei, Guo-Jian; Zhou, Ding

2014-04-01

Different forms of heavy metals in soil will produce different environmental effects, and will directly influence the toxicity, migration and bioavailability of heavy metals. This study used lime, fly ash, dried sludge, peanut shells as stabilizers in the treatment of heavy metals in mineral waste residues. Morphological analyses of heavy metal, leaching experiments, potted plant experiments were carried out to analyze the migration and transformation of heavy metals. The results showed that after adding stabilizers, the pH of the acidic mineral waste residues increased to more than neutral, and the organic matter content increased significantly. The main existing forms of As, Pb, and Zn in the mineral waste residues were the residual. The contents of exchangeable and organic matter-bound As decreased by 65.6% and 87.7% respectively after adding fly ash, dried sludge and peanut shells. Adding lime, fly ash and peanut shells promoted the transformation of As from the Fe-Mn oxide-bound to the carbonate-bound, and adding lime and fly ash promoted the transformation of Pb and Zn from the exchangeable, Fe-Mn oxide-bound, organic matter-bound to the residual. After the early stage of the stabilization treatment, the contents of As, Pb and Zn in the leachate had varying degrees of decline, and adding peanut shells could reduce the contents of As, Pb and Zn in the leachate further. Among them, the content of As decreased most significantly after treatment with fly ash, dried sludge and peanut shells, with a decline of 57.4%. After treatment with lime, fly ash and peanut shells, the content of Zn decreased most significantly, by 24.9%. The addition of stabilizers was advantageous to the germination and growth of plants. The combination of fly ash, dried sludge and peanut shell produced the best effect, and the Vetiveria zizanioides germination rate reached 76% in the treated wasted mineral residues.

Studies on the content of heavy metals in Aries River using ICP-MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voica, Cezara, E-mail: Cezara.Voica@itim-cj.ro; Kovacs, Melinda, E-mail: Cezara.Voica@itim-cj.ro; Feher, Ioana, E-mail: Cezara.Voica@itim-cj.ro

2013-11-13

Among the industrial branches, the mining industry has always been an important source of environmental pollution, both aesthetically and chemically. Through this paper results of ICP-MS characterization of Aries River Basin are reported. Mining activities from this area has resulted in contamination of environment and its surrounding biota. This is clearly evidenced in analyzed water samples, especially from Baia de Aries site where increased amount of trace elements as Cr, Zn, As, Se, Cd, Pb and U were founded. Also in this site greater amount of rare earth elements was evidenced also. Through monitoring of Aries River from other non-miningmore » area it was observed that the quantitative content of heavy metals was below the maximum permissible levels which made us to conclude that the water table wasn't seriously affected (which possibly might be attributed to the cessation of mining activities in this area from a few years ago)« less

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

PubMed

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

2012-03-01

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

Heavy metal stabilization in contaminated road-derived sediments.

PubMed

Rijkenberg, Micha J A; Depree, Craig V

2010-02-01

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

Bioethanol production from recovered napier grass with heavy metals.

PubMed

Ko, Chun-Han; Yu, Fan-Chun; Chang, Fang-Chih; Yang, Bing-Yuan; Chen, Wen-Hua; Hwang, Wen-Song; Tu, Ta-Chih

2017-12-01

Using plants to absorb and accumulate heavy metals from polluted soil, followed by the recycling of explants containing heavy metals, can help achieve the goal of reverting contaminated soil to low heavy-metal content soil. However, the re-use of recovered explants can also be problematic. Meanwhile, bioethanol has become a popular energy source. In this study, napier grass was used for the remediation of soil contaminated with heavy metals (artificially contaminated soil). The influence of bioethanol production from napier grass after phytoremediation was also investigated. The concentration of Zn, Cd, and Cr in the contaminated soil was 1000, 100, and 250 mg/kg, respectively. After napier grass phytoremediation, the concentration (dry biomass) of Zn, Cd, and Cr in the explants was 2701.97 ± 173.49, 6.1 ± 2.3, and 74.24 ± 1.42 mg/kg, respectively. Biomass production in the unpolluted soil was 861.13 ± 4.23 g. The biomass production ratio in high Zn-polluted soil was only 3.89%, while it was 4.68% for Cd and 21.4% for Cr. The biomass obtained after napier grass phytoremediation was pretreated using the steam explosion conditions of 180 °C, for 10 min, with 1.5% H 2 SO 2 , followed by enzymatic hydrolysis. The efficiency of enzymatic hydrolysis for Zn-polluted biomass was 90% of the unpolluted biomass, while it was 77% for Cd, and approximately the same for Cr. The fermentation efficiency of the heavy-metal-containing biomass was higher than the control biomass. The fermentation ethanol concentration obtained was 8.69-12.68, 13.03-15.50, and 18.48-19.31 g/L in Zn, Cd, and Cr environments, respectively. Results show that the heavy metals had a positive effect on bacteria fermentation. However, the fermentation efficiency was lower for biomass with severe heavy metal pollution. Thus, the utilization of napier grass phytoremediation for bioethanol production has a positive effect on the sustainability of environmental resources. Copyright © 2017

[Study on distribution of five heavy metal elements in different parts of Cordyceps sinensis by microwave digestion ICP-MS].

PubMed

Zhou, Li; Hao, Qing-Xiu; Wang, Sheng; Yang, Quan; Kang, Chuan-Zhi; Yang, Wan-Zhen; Guo, Lan-Ping

2017-08-01

The contents of five heavy metals (Cu, Pb, As, Cd, Hg) in 17 batches of Cordyceps sinensis were determined by microwave digestion-ICP-MS, and their distribution in C. sinensis were analyzed. The results showed that the contents of Cu, Pb, Cd and Hg in all batches were in accordance with the international standards of Chinese Medicine-Chinese Herbal Medicine Heavy Metal Limit, with their contents in the stroma higher than that in the caterpillar body, and the excess rate of As, which mainly concentrated in the caterpillar body part of C. sinensis, was 88.24%, as the content of As in the caterpillar body was 7 to 12 fold of that in the stroma. In this study, the distribution of five heavy metals in C. sinensis was clarified, and the existing problems of arsenic limit of heavy metal in C. sinensis were analyzed, and some suggestions were put forward. It is hoped that the reference standard can be provided for the limited standard of arsenic in C. sinensis. Copyright© by the Chinese Pharmaceutical Association.

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.

Fate and transport of heavy metals and radioelements in groundwater aquifers of Al-Qunfudhah and Wadi Haliy quadrangles, southwest of Saudi Arabia

NASA Astrophysics Data System (ADS)

Bajabaa, S. A.; Abd El-Naby, H.; Dawood, Y.

2009-12-01

The fate and transport of heavy metals and radioelements in groundwater aquifers in five wadis located in the Al Qunfudhah and Wadi Haliy quadrangles were investigated. These wadis are an important source of water to the Red Sea coastal plain. Copper, zinc and other base-metals mineralization occur at eastern parts of these quadrangles that dominates the water catchments area of these wadis. Water, rock and soil samples were collected from all wadis and they were analyzed for major, trace elements, heavy metals and stable isotopes. The chemical and isotopic results showed active water/rock interaction. The preliminary investigation of the data analyses showed some samples with high heavy metals and uranium contents. Generally, the uranium and heavy metal contents are higher in samples collected from the upstream area of each wadi where the crystalline rocks are exposed and direct contact with the runoff. The uranium contents were as high as 120 ppb in some water samples. These elevated values are mainly due to two factors water rock interaction and concentration through evaporation. It was also observed to have elevated heavy metal contents near mining activates, which suggests that these mining activates are playing an important role in mobilizing the heavy elements and in turn affecting the water quality in these wadis.

Heavy Metal Risk Management: Case Analysis

PubMed Central

Kim, Ji Ae; Lee, Seung Ha; Choi, Seung Hyun; Jung, Ki Kyung; Park, Mi Sun; Jeong, Ji Yoon; Hwang, Myung Sil; Yoon, Hae Jung; Choi, Dal Woong

2012-01-01

To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends calculating the provisional tolerable weekly intake (PTWI) of individual heavy metals instead of the acceptable daily intake (ADI) to compare their pollution levels considering their toxicity accumulated in the human body. In Korea, exposure assessments have been conducted, and in other countries, hazardous substances are controlled by various governing bodies. As such, in Korea and other countries, diverse food heavy metal monitoring and human body exposure assessments are conducted, and reducing measures are prepared accordingly. To reduce the danger of hazardous substances, many countries provide leaflets and guidelines, develop hazardous heavy metal intake recommendations, and take necessary actions. Hazard control case analyses can assist in securing consumer safety by establishing systematic and reliable hazard control methods. PMID:24278603

[Hyperspectral remote sensing in monitoring the vegetation heavy metal pollution].

PubMed

Li, Na; Lü, Jian-sheng; Altemann, W

2010-09-01

Mine exploitation aggravates the environment pollution. The large amount of heavy metal element in the drainage of slag from the mine pollutes the soil seriously, doing harm to the vegetation growing and human health. The investigation of mining environment pollution is urgent, in which remote sensing, as a new technique, helps a lot. In the present paper, copper mine in Dexing was selected as the study area and China sumac as the study plant. Samples and spectral data in field were gathered and analyzed in lab. The regression model from spectral characteristics for heavy metal content was built, and the feasibility of hyperspectral remote sensing in environment pollution monitoring was testified.

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

PubMed

Li, Haiyan; Shi, Anbang; Zhang, Xiaoran

2015-06-01

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments (RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size (<150 μm) were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal (i.e., Cu, Zn, Pb and Cd) content was the largest in particles with small size (<150 μm) among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, respectively. Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index (Igeo) decreased in the order: Cd>Pb>Cu>Zn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: Cd>Zn≈Pb>Cu. Copyright © 2015. Published by Elsevier B.V.

Characterization of typical heavy metals in pyrolysis MSWI fly ash.

PubMed

Xu, Tengtun; Wang, Li'ao; Zeng, Yunmin; Zhao, Xue; Wang, Lei; Zhan, Xinyuan; Li, Tong; Yang, Lu

2018-06-07

Thermal treatment methods are used extensively in the process of municipal solid waste incineration fly ash. However, the characterization of heavy metals during this process should be understood more clearly in order to control secondary pollution. In this paper, the content, speciation and leaching toxicity of mercury (Hg), plumbum (Pb), cadmium (Cd) and zinc (Zn) in fly ash treated under different temperatures and time were firstly analysed as pre-tests. Later, pilot-scale pyrolysis equipment was used to explore the concentration and speciation changes in the heavy metals of fly ash. Finally, the phase constitution and microstructure changes in fly ash were compared before and after pyrolysis using X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The results showed that (a) The appropriate processing temperature was between 400°C and 450°C, and the processing time should be 1 h. (b) The stability of heavy metals in fly ash increased after pyrolysis. (c) XRD and SEM results indicated that phase constitution changed a little, but the microstructure varied to a porous structure similar to that of a coral reef after pyrolysis. These results suggest that pyrolysis could be an effective method in controlling heavy metal pollution in fly ash.

[Determination of trace heavy metal elements in cortex Phellodendron chinense by ICP-MS after microwave-assisted digestion].

PubMed

Kou, Xing-Ming; Xu, Min; Gu, Yong-Zuo

2007-06-01

An inductively coupled plasma mass spectrometry (ICP-MS) for determination of the contents of 8 trace heavy metal elements in cortex Phellodendron chinense after microwave-assisted digestion of the sample has been developed. The accuracy of the method was evaluated by the analysis of corresponding trace heavy metal elements in standard reference materials (GBW 07604 and GBW 07605). By applying the proposed method, the contents of 8 trace heavy metal elements in cortex Phellodendron chinense cultivated in different areas (in Bazhong, Yibin and Yingjing, respectively) of Sichuan and different growth period (6, 8 and 10 years of samples from Yingjing) were determined. The relative standard deviation (RSD) is in the range of 3.2%-17.8% and the recoveries of standard addition are in the range of 70%-120%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of 8 trace heavy metal elements in cortex Phellodendron chinense. The results also show that the concentrations of 4 harmful trace heavy metal elements As, Cd, Hg and Pb in cortex Phellodendron chinense are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation. Therefore, the cortex Phellodendron chinense is fit for use as medicine and export.

Biomagnetic monitoring of heavy metals contamination in deposited atmospheric dust, a case study from Isfahan, Iran.

PubMed

Norouzi, Samira; Khademi, Hossein; Cano, Angel Faz; Acosta, Jose A

2016-05-15

Tree leaves are considered as one of the best biogenic dust collectors due to their ability to trap and retain particulate matter on their surfaces. In this study, the magnetic susceptibility (MS) and the concentration of selected heavy metals of plane tree (Platanus orientalis L.) leaves and deposited atmospheric dust, sampled by an indirect and a direct method, respectively, were determined to investigate the relationships between leaf magnetic parameters and the concentration of heavy metals in deposited atmospheric dust. The objective was to develop a biomagnetic method as an alternative to the common ones used for determining atmospheric heavy metal contaminations. Plane tree leaves were monthly sampled on the 19th of May to November, 2012 (T1-T7), for seven months from 21 different sites in the city of Isfahan, central Iran. Deposited atmospheric dust samples were also collected using flat glass surfaces from the same sites on the same dates, except for T1. MS (χlf, χhf) values in washed (WL) and unwashed leaves (UL) as well as Cu, Fe, Mn, Ni, Pb, and Zn concentrations in UL and deposited atmospheric dust samples were determined. The results showed that the MS content with a biogenic source was low with almost no significant change during the sampling period, while an increasing trend was observed in the MS content of UL samples due to the deposition of heavy metals and magnetic particles on leaf surfaces throughout the plant growth. The latter type of MS content could be reduced through washing off by rain. Most heavy metals examined, as well as the Tomlinson pollution load index (PLI) in UL, showed statistically significant correlations with MS values. The correlation between heavy metals content in atmospheric dust deposited on glass surfaces and leaf MS values was significant for Cu, Fe, Pb, and Zn. Moreover, the similarity observed between the spatial distribution maps of leaf MS and deposited atmospheric dust PLI provided convincing evidence regarding

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.

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

Determination of heavy metals in the ambient atmosphere.

PubMed

Suvarapu, Lakshmi Narayana; Baek, Sung-Ok

2017-01-01

Heavy metal determination in ambient air is an important task for environmental researchers because of their toxicity to human beings. Some heavy metals (hexavalent chromium (Cr), arsenic (As), cadmium (Cd) and nickel (Ni)) have been listed as carcinogens. Furthermore, heavy metals in the atmosphere can accumulate in various plants and animals and enter humans through the food chain. This article reviews the determination of heavy metals in the atmosphere in different areas of the world since 2006. The results showed that most researchers concentrated on toxic metals, such as Cr, Cd, Ni, As and lead. A few studies used plant materials as bio-monitors for the atmospheric levels of heavy metals. Some researchers found higher concentrations of heavy metals surrounding industrial areas compared with residential and/or commercial areas. Most studies reported the major sources of the particulate matter and heavy metals in the atmosphere to be industrial emissions, vehicular emissions and secondary aerosols.

[Toxic heavy metals in foodstuffs (author's transl)].

PubMed

Käferstein, F K

1980-09-01

1. In the Federal Republic of Germany two staple foodstuffs, cereals and milk, are regularly checked by means of monitoring programmes for their content of heavy metals, this check being representative for the whole country. Other foodstuffs are analysed in the laboratories of the Food Control Authorities, but these inspections are carried out rather sporadically and are not yet of a "monitoring" nature. 2. The measured values from a number of laboratories are fed into a central data bank (Datenbank-ZEBS) at the Federal Health Office and are thus available for statistical and hygienic evaluation. 3. At present, information is available on the lead, cadmium and mercury content of foodstuffs which represent roughly 70 to 80 per cent of the food consumed by an average adult. The intake of lead, cadmium and mercury due to the consumption of these foodstuffs has been calculated and extrapolated to the complete food consumption. It was found that the value ascertained are clearly lower than the toxicological threshold values published by FAO/WHO. 4. Nevertheless, the intake needs to be limited, because the average heavy metal content of some foodstuffs has increased, probably because of anthropogenic reasons. This is especially likely to apply to the cadmium content of wheat. To attempt a restriction by regulation, is at present not considered in Germany to be the optimal solution. Instead, the Federal Health Office has published guidance values which contain an appeal to the foodstuff industry and food control authorities to investigate the causes, whenever these guidance values are approached or exceeded, with the objective of avoiding high levels.

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.

[Heavy metal concentration in Nanjing urban soils and their affecting factors].

PubMed

Lu, Ying; Gong, Zitong; Zhang, Ganlin; Zhang, Bo

2004-01-01

The concentration and source of heavy metals in Nanjing urban soils and their relationships with soil properties were studied. The results indicated that the soils in Nanjing urban were not obviously polluted by Fe, Ni, Co and V, but polluted by Mn, Cr, Cu, Zn, and Pb to a certain extent. The heavy metals were irregularly distributed in soil profiles. Fe, Ni, Co, and V were originated from soil materials, but Cu, Zn, Pb, and Cr were anthropogenic input. Probably, Mn had different origins in different soils. There were positive correlations among Fe, Cr, Ni, Co, and V concentration, and among Cu, Zn, Pb, and Cr concentration. The Fe, Co, V, and Ni concentration were positively correlated with soil clay content and CEC, and the Cu, Zn and Pb concentration were negatively correlated with clay content. There were positive correlations between Cu, Zn, Pb and Cr concentration and organic C content, and between Pb concentration and soil pH.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Plant rhamnogalacturonan II complexation of heavy metal cations

DOEpatents

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

1999-03-02

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

Plant rhamnogalacturonan II complexation of heavy metal cations

DOEpatents

O'Neill, Malcolm A.; Pellerin, Patrice J. M.; Warrenfeltz, Dennis; Vidal, Stephane; Darvill, Alan G.; Albersheim, Peter

1999-01-01

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

Heavy metals in vegetables sold in the local market in Jordan.

PubMed

Osaili, Tareq M; Al Jamali, Abbas F; Makhadmeh, Ibrahim M; Taha, Mohammad; Jarrar, Sukiena K

2016-09-01

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009-0.275 mg kg(-1) wet weight, 0.004-0.060 mg kg(-1), 0.003-0.401 mg kg(-1), 0.105-3.51 mg kg(-1), 0.15-1.15 mg kg(-1), 0.93-14.39 mg kg(-1), 0.044-0.702 mg kg(-1), 0.072-0.289 mg kg(-1) and 2.23-6.65 mg kg(-1), respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.

Heavy Metal Uptake by Novel Miscanthus Seed-Based Hybrids Cultivated in Heavy Metal Contaminated Soil

NASA Astrophysics Data System (ADS)

Krzyżak, Jacek; Pogrzeba, Marta; Rusinowski, Szymon; Clifton-Brown, John; McCalmont, Jon Paul; Kiesel, Andreas; Mangold, Anja; Mos, Michal

2017-09-01

When heavy metal contaminated soils are excluded from food production, biomass crops offer an alternative commercial opportunity. Perennial crops have potential for phytoremediation. Whilst the conditions at heavy metal contaminated sites are challenging, successful phytoremediation would bring significant economic and social benefits. Seed-based Miscanthus hybrids were tested alongside the commercial clone Miscanthus × giganteus on arable land, contaminated with Pb, Cd and Zn near Katowice. Before the randomized experimental plots were established (25m2 plots with plant density 2/m2) `time-zero' soil samples were taken to determine initial levels of total (aqua regia) and bioavailable (CaCl2 extraction) concentration of Pb, Cd and Zn. After the growing season plant material was sampled during autumn (October, green harvest) and winter (March, brown harvest) to determine differences in heavy metal uptake. Results after the first growing season are presented, including the plot establishment success, biomass yield and heavy metal uptake.

The distribution, contamination and risk assessment of heavy metals in sediment and shellfish from the Red Sea coast, Egypt.

PubMed

El Nemr, Ahmed; El-Said, Ghada F; Ragab, Safaa; Khaled, Azza; El-Sikaily, Amany

2016-12-01

Zn, Cu, Ni, V, Al, Pb, Cd, Hg, lipid and water contents were determined in the soft tissues of different shellfish species collected along the Red Sea shoreline. Metal contents showed a descending order of Zn > Cu > Ni > Al > V > Pb > Cd > Hg. The leachable concentrations found in the sediments gathered from the studied locations gave another descending order: Al > Zn > Ni > Pb > V > Cu > Cd. The determined leachable heavy metal contents in the sediment did not exceed the NOAA and CCME (Anonymous 1999) sediment quality guidelines. Accordingly, the sediments along the Egyptian Red Sea area did not pose any adverse impacts on the biological life. According to the hazard quotient (HQ) calculations for heavy metal contents in the soft tissue of shellfish, mercury did not pose any risk on human health; whereas, the other determined heavy metals gave HQ values of 1 < HQ < 10 and showed a possibility of risk on the long term. Cu is above the desirable levels in mussels. The RQ calculations of toddlers and adults reflected that Cu was the only heavy metal that had an adverse effect on toddlers' health. Based on the human organizations (EPA, BOE, MAFF, and NHMRC) that proposed safety concentrations of heavy metals, the studied shellfish were somewhat safe for human consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pollution characteristics and ecological risk of heavy metals in ballast tank sediment.

PubMed

Feng, Daolun; Chen, Xiaofei; Tian, Wen; Qian, Qun; Shen, Hao; Liao, Dexiang; Lv, Baoyi

2017-02-01

This study was conducted to illustrate the contents and potential ecological risk of heavy metals in ballast tank sediment. Ballast sediment samples were collected from six ships during their stay in shipyard, and the heavy metals were determined by inductive coupled plasma emission spectrometer. Results showed that high concentrations of heavy metals were detected in all six sediment samples following the order: Zn > Cu > Pb > Cr > As > Cd > Hg. The geoaccumulation index explained the average pollution degree of heavy metals decreased as the following: Zn > Pb > Cu > As > Cr > Hg, and the environmental risk indices suggested that concentration found of Zn, Pb, and Cu might be highly toxic to aquatic organisms. Principal component and correlation analysis indicated the metal pollution in ballast tank sediment was affected by complex and different contamination mechanisms, and the corrosion of ballast tank played an important role in this process. In conclusion, this study is very useful for comprehensive consideration and efficient management of ballast tank sediment in order to protect the marine environment.

Trends and sources for heavy metals in urban atmosphere

NASA Astrophysics Data System (ADS)

Kemp, Kåre

2002-04-01

The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing.

Distribution, Fraction, and Ecological Assessment of Heavy Metals in Sediment-Plant System in Mangrove Forest, South China Sea.

PubMed

Li, Ruili; Chai, Minwei; Qiu, Guo Yu

2016-01-01

Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest.

Distribution, Fraction, and Ecological Assessment of Heavy Metals in Sediment-Plant System in Mangrove Forest, South China Sea

PubMed Central

Li, Ruili; Chai, Minwei; Qiu, Guo Yu

2016-01-01

Overlying water, sediment, rhizosphere sediment and mangrove seedlings in the Futian mangrove forest were analyzed for heavy metals. The results showed that mangrove plant acidified sediment and increased organic matter contents. Except for chromium (Cr), nickel (Ni) and copper (Cu) in Aegiceras corniculatum sediment, heavy metals in all sediments were higher than in overlying water, rhizosphere sediment and mangrove root. Heavy metals in Avicennia marina sediments were higher than other sediments. The lower heavy metal biological concentration factors (BCFs) and translocation factors (TFs) indicated that mangrove plant adopted exclusion strategy. The geo-accumulation index, potential ecological risk index and risk assessment code (RAC) demonstrated that heavy metals have posed a considerable ecological risk, especially for cadmium (Cd). Heavy metals (Cr, Ni, Cu and Cd) mainly existed in the reducible fractions. These findings provide actual heavy metal accumulations in sediment-plant ecosystems in mangrove forest, being important in designing the long-term management and conservation policies for managers of mangrove forest. PMID:26800267

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

PubMed

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

2005-01-01

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

Heavy metal distribution in sediment profiles of Tuul River, Mongolia

NASA Astrophysics Data System (ADS)

Soyol-Erdene, T. O.; Lin, S.; Tuuguu, E.; Daichaa, D.; Ulziibat, B.; Enkh-Amgalan, T.; Hsieh, I. C.

2016-12-01

The distribution, enrichment, and accumulation of heavy metals in the sediments of Tuul River, Mongolia were investigated. Sediment core samples with depths of 4.0-49 cm from thirteen locations along the Tuul River were collected in the period from Sept. 2013 to Aug. 2014 and characterized for metal contents (e.g., Al, Fe, Cu, Zn, Pb, Ni, Cd, Hg and Cr), water content, and grain size. Results showed that metal average concentrations in the sample cores varied from 0.02 mg kg-1 for Hg (0.01 - 0.03 mg kg-1) to 481 mg kg-1 for Mn (277 - 623 mg kg-1). Metal concentrations at the downstream of the capital city were higher than those at other locations. All heavy metals studied, had average enrichment factors less than 3.0, but some sites had relatively higher values of enrichment factors up to 18 for Cu, 4.1 for Hg, 5.9 for Zn, and 25 for Cr, especially at middle depth ( 8-12 cm) of the cores. Importantly, severe pollution of mercury (Hg) was found at the downstream of the capital city which requires immediate remediation before this metal propagates into the food chain. Metal concentrations correlated to the physical-chemical properties of the sediments, which suggested the influence of industrial and municipal wastewaters discharged from the nearby cities. Results of this work would help to develop strategy to remediate of Tuul river sediment and to reduce the exposure of inhabitants to toxic substances.

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.

The Relationship between TOC and pH with Exchangeable Heavy Metal Levels in Lithuanian Podzols

NASA Astrophysics Data System (ADS)

Khaledian, Yones; Pereira, Paulo; Brevik, Eric C.; Pundyte, Neringa; Paliulis, Dainius

2017-04-01

Heavy metals can have a negative impact on public and environmental health. The objective of this study was to investigate the relationship between total organic carbon (TOC) and pH with exchangeable heavy metals (Pb, Cd, Cu and Zn) in order to predict exchangeable heavy metal content in soils sampled near Panevėžys and Kaunas, Lithuania. Principal component regression (PCR) and nonlinear regression methods were tested to find the statistical relationship between TOC and pH with heavy metals. The results of PCR [R2 = 0.68, RMSE = 0.07] and non-linear regression [R2 = 0.74, RMSE= 0.065] (pH with TOC and exchangeable parameters) were statistically significant. However, this was not observed in the relationships of pH and TOC separately with exchangeable heavy metals. The results indicated that pH had a higher correlation with exchangeable heavy metals (non-linear regression [R2 = 0.72, RMSE= 0.066]) than TOC with heavy metals [R2 = 0.30, RMSE= 0.004]. It can be concluded that even though there was a strong relationship between TOC and pH with exchangeable metals, the metal mobility (exchangeable metals) can be explained by pH better than TOC in this study. Finally, manipulating soil pH could likely be productive to assess and control heavy metals when financial and time limitations exist (Khaledian et al. 2016). Reference(s) Khaledian Y, Pereira P, Brevik E.C, Pundyte N, Paliulis D. 2016. The Influence of Organic Carbon and pH on Heavy Metals, Potassium, and Magnesium Levels in Lithuanian Podzols. Land Degradation and Development. DOI: 10.1002/ldr.2638

The Heavy Metal Subculture and Suicide.

ERIC Educational Resources Information Center

Stack, Steven; And Others

1994-01-01

Assessed relationship between heavy metal music and suicide with data on heavy metal magazine subscriptions and youth suicide in 50 states. Found that, controlling for other predictors of suicide, greater strength of metal subculture, higher youth suicide rate, suggests that music perhaps nurtures suicidal tendencies already present in subculture.…

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.

Heavy metals and arsenic content in water along the southern Caspian coasts in Iran.

PubMed

Abadi, Mohammad; Zamani, Abbasali; Parizanganeh, Abdolhossein; Khosravi, Younes; Badiee, Hamid

2018-06-06

Due to the importance of pollution monitoring in marine ecosystems and lack of a coherent and systematic investigation of heavy metal ions along the southern shores of the Caspian Sea, in the present study, the amount of these metals and As ions in coastal waters along its 780-km-long coast in Iran have been studied. Heavy metals (cobalt, nickel, copper, zinc, cadmium, mercury, lead) and a poisonous metalloid (arsenic) were selected in 59 sampling stations and determined using differential pulse polarography method. The multivariate statistical tools were applied to describe and interpret the experimental data. The overall mean concentrations of studied metals (in microgram per liter; μg L -1 ) in the samples were found in the order Zn (10.9) > Ni (7.4) > Cu (5.5) > Pb (1.9) > Hg (1.4) > As (1.3) > Co (1.1) > Cd (0.2). The results when compared with reported international standards confirmed that the sampled waters do contain some of these elements above the suggested maximum permissible limits. Hg and Cu were detected in 54.2 and 72.9% of the samples, almost all above the permissible limits. Ni, Zn, Pb, and Co were detected in 100, 96.6, 93.2, and 88.1%, respectively, while 8.5, 22.0, 3.4, and 1.7% were above the permissible limits. Cd and As were present in 61 and 93% of the samples, and their concentrations were higher than the rate presented by Russian System of Management Chemicals (RSMC). In addition, spatial distribution of heavy metal concentrations showed that Gorgan Bay is an ecosystem serving as a filter, trapping natural and anthropogenic materials that are brought from industrial, commercial, and urbanized areas. The multivariate data analysis reveals that Caspian Sea is contaminated by both anthropogenic as well as pedo-geochemical sources.

Concentration and distribution of heavy metals in two Andisols of the Azuay Andes (Ecuador)

NASA Astrophysics Data System (ADS)

Bech, Jaume; Roca, Núria; Ugalde, Sandra; Tonon, Luis; Larriva, Giovani

2013-04-01

At present many governmental and environmental bureaus are interested in establishing reliable soil quality criteria for heavy metals to enable the detection of polluted sites. To evaluate the variation of heavy metal natural concentration and to assess heavy metal contamination in soils, it is necessary to survey heavy metal baseline levels in order to understand their migration and distribution during pedogenesis. Many nationwide projects report elemental baseline values in soils. Baseline levels of heavy metals in soils have also been determined at local scales. Data is scarce on qualitative and quantitative trace elements content of Ecuatorian soils. The soils in the Azuay Andes (S of Ecuador) are thought to be generally non-contaminated. The objective of this study is to determine and evaluate the natural concentrations and distribution of seven heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) in Andisol of Azuay Andes. Soil samples were grounded in an agate mill prior to pseudototal heavy metal analysis. Cadmium, Co, Cr, Cu, Ni, Pb and Zn were determined by a masses spectrometer (MS-ICP) after aqua regia extraction according to ISO standard procedures. Soil particle size distribution, organic carbon, electrical conductivity and pH have been previously determined. Andisols are dominated by amorphous aluminium silicates and Al-organic complexes. The soils of volcanic area usually have an Ah-Bh-Bhs/Bw-C horizon sequence. The Ah horizon is dark-coloured and normally very high in organic matter, ranging from 6.4 to 15.2 %. A strong rise in pH upon addition of a fluoride solution is used to signal the presence of allophane. The pH usually rises to 10.5 bellow 20 cm. The range of total soil values in mgkg-1 is as follows: Cd (0.03-0.3), Co (0.8-5), Cr (7-15), Cu (9-25), Ni (2-4), Pb (11-41) and Zn (12-37). All heavy metal contents, except for Cd, are strongly correlated with pH. For the pseudototal fraction, there was significant difference between the soil horizons in

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.

Spatial distribution and source identification of heavy metals in surface soils in a typical coal mine city, Lianyuan, China.

PubMed

Liang, Jie; Feng, Chunting; Zeng, Guangming; Gao, Xiang; Zhong, Minzhou; Li, Xiaodong; Li, Xin; He, Xinyue; Fang, Yilong

2017-06-01

In this study, we investigated the pollution degree and spatial distribution of heavy metals and determined their sources in topsoil in a typical coal mine city, Lianyuan, Hunan Province, China. We collected 6078 soil surface samples in different land use types. And the concentrations of Zn, Cd, Cu, Hg, Pb, Sb, As, Mo, V, Mn, Fe and Cr were measured. The average contents of all heavy metals were lower than their corresponding Grade II values of Chinese Soil Quality Standard with the exception of Hg. However, average contents of twelve heavy metals, except for Mn, exceeded their background level in soils in Hunan Province. Based on one-way analysis of variance (ANOVA), the contents of Cu, Zn, Cd, Pb, Hg, Mo and V were related to the anthropogenic source and there were statistically significant differences in their concentrations among different land use patterns. The spatial variation of heavy metal was visualized by GIS. The PMF model was used to ascertain contamination sources of twelve heavy metals and apportion their source contributions in Lianyuan soils. The results showed that the source contributions of the natural source, atmospheric deposition, industrial activities and agricultural activities accounted for 33.6%, 26.05%, 23.44% and 16.91%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Characteristics and Risk Assessment of Heavy Metals in Core Sediments from Lakes of Tibet].

PubMed

Guo, Bi-xi; Liu, Yong-qin; Zhang, Fan; Hou, Ju-zhi; Zhang, Hong-bo

2016-02-15

To explore the source of heavy metals in lake sediments and their hazard to environment on Tibetan Plateau, China, heavy metal (Cu, Zn, Cd, Pb, Cr, Co, Ni and As) levels in surface sediments of 18 lakes were investigated. Inductively Coupled Plasma Mass Spectrometry (ICP-MS, X-7 series) was used to determine the contents of heavy metals and the concentrations of carbon and nitrogen in sediment samples were analyzed by element analyzer (Vario Max CN, Elementar, Germany). The average concentrations for Cu, Zn, Cd, Pb, Cr, Co, Ni and As were 24.61 mg x kg(-1), 70.14 mg x kg(-1), 0.26 mg x kg(-1), 25.43 mg x kg(-1), 74.12 mg x kg(-1), 7.93 mg x kg(-1), 33.85 mg x kg(-1), 77.69 mg x kg(-1). It was found that heavy-metal concentrations in Tibet sediments were higher than those in Antarctic, but lower than those in the regions affected by anthropogenic activities. The contents of Cu, Zn, Pb, Cr and Co in the samples were lower than the background values of Tibet. Correlation analysis and principal components analysis (PCA) were used to analyze the origins of heavy metals. The result showed that Cu, Zn, Cd, Pb, Co, Ni and As came from soil in drainage basin and atmospheric deposition. Cr was mainly affected by human activities. Assessment on ecological risk of heavy metals was carried out using Hakanson's method and cluster analysis (CA). Assessment on ecological risk indicated that Pumoyum Co, Longmo Co and Bangong Co were at low risks, Bieruoze Co was at high ecological risk level and the other lakes were at different risk levels.

Bioremoval of heavy metals by bacterial biomass.

PubMed

Aryal, Mahendra; Liakopoulou-Kyriakides, Maria

2015-01-01

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

Environmental security control of resource utilization of shale gas' drilling cuttings containing heavy metals.

PubMed

Wang, Chao-Qiang; Lin, Xiao-Yan; Zhang, Chun; Mei, Xu-Dong

2017-09-01

The overall objective of this research project was to investigate the heavy metals environmental security control of resource utilization of shale gas' drilling cuttings. To achieve this objective, we got through theoretical calculation and testing, ultimately and preliminarily determine the content of heavy metals pollutants, and compared with related standards at domestically and abroad. The results indicated that using the second Fike's law, the theoretical model of the release amount of heavy metal can be made, and the groundwater environmental risk as main point compared with soil. This study can play a role of standard guidance on environmental security control of drilling cuttings resource utilization by the exploration and development of shale gas in our country.

[Pollution Characteristics and Potential Ecological Risk of Heavy Metals in Urban Surface Water Sediments from Yongkang].

PubMed

Qi, Peng; Yu, Shu-quan; Zhang, Chao; Liang, Li-cheng; Che, Ji-lu

2015-12-01

In order to understand the pollution characteristics of heavy metals in surface water sediments of Yongkang, we analyzed the concentrations of 10 heavy metals including Ti, Cr, Mn, Co, Ni, Cu, Zn, As, Pb and Fe in 122 sediment samples, explored the underlying source of heavy metals and then assessed the potential ecological risks of those metals by methods of the index of geo-accumulation and the potential ecological risk. The study results showed that: 10 heavy metal contents followed the order: Fe > Ti > Mn > Zn > Cr > Cu > Ph > Ni > As > Co, all heavy metals except for Ti were 1. 17 to 3.78 times higher than those of Zhejiang Jinhua- Quzhou basin natural soils background values; The concentrations of all heavy metals had a significantly correlation between each other, indicating that those heavy metals had similar sources of pollution, and it mainly came from industrial and vehicle pollutions; The pollution extent of heavy metals in sediments by geo-accumulation index (Igeo) followed the order: Cr > Zn > Ni > Cu > Fe > As > Pb >Mn > Ti, thereinto, Cr, Zn, Cu and Ni were moderately polluted or heavily polluted at some sampling sites; The potential ecological risk of 9 heavy metals in sediments were in the following order: Cu > As > Ni > Cr > Pb > Co > Zn > Mn > Ti, Cu and As contributed the most to the total potential ecological risk, accounting for 22.84% and 21. 62% , others had a total of 55.54% , through the ecological risk assessment, 89. 34% of the potential ecological risk indexes ( RI) were low and 10. 66% were higher. The contamination level of heavy metals in Yongkang was slight in total, but was heavy in local areas.

Bioremediation of Toxic Heavy Metals: A Patent Review.

PubMed

Verma, Neelam; Sharma, Rajni

2017-01-01

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

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

PubMed

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

2015-04-01

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

Heavy Metal Poisoning and Cardiovascular Disease

PubMed Central

Alissa, Eman M.; Ferns, Gordon A.

2011-01-01

Cardiovascular disease (CVD) is an increasing world health problem. Traditional risk factors fail to account for all deaths from CVD. It is mainly the environmental, dietary and lifestyle behavioral factors that are the control keys in the progress of this disease. The potential association between chronic heavy metal exposure, like arsenic, lead, cadmium, mercury, and CVD has been less well defined. The mechanism through which heavy metals act to increase cardiovascular risk factors may act still remains unknown, although impaired antioxidants metabolism and oxidative stress may play a role. However, the exact mechanism of CVD induced by heavy metals deserves further investigation either through animal experiments or through molecular and cellular studies. Furthermore, large-scale prospective studies with follow up on general populations using appropriate biomarkers and cardiovascular endpoints might be recommended to identify the factors that predispose to heavy metals toxicity in CVD. In this review, we will give a brief summary of heavy metals homeostasis, followed by a description of the available evidence for their link with CVD and the proposed mechanisms of action by which their toxic effects might be explained. Finally, suspected interactions between genetic, nutritional and environmental factors are discussed. PMID:21912545

Depuration Study of Heavy Metal Lead (Pb) and Copper (Cu) in Green Mussels Perna viridis through Continues-discontinues and Acid Extraction Methods

NASA Astrophysics Data System (ADS)

Budiawan; Bakri, Ridla; Cahaya Dani, Intan; Handayani, Sri; Ade Kurnia Putri, Rizki; Tamala, Riska

2018-01-01

Green mussel or Perna viridis is filter feeder, which is very susceptible to heavy metals. It takes an effort to release heavy metal contents on the green shell, one of method that can be used to release heavy metal from green shell is depuration proccess. In this research, the depuration process was conducted by continues method of depuration, discontinues method by using various kind of water and acid extraction. The optimum time of continues depuration method is 1.5 hours, with circulation speed 250 L/h and result of Pb metal content decreased is equal to 30.048% and 29.748% for Cu. In the discontinues method, the optimum result was reached at 100oC by using PAM water as the media at 3 h immersion period with decrease of Pb metal content 35.001% and Cu metal content 39.015%. In the acid extraction method, the optimum condition was achieved by 11% acetic acid solvent with decreasing of Pb and Cu levels are 88.224% and 76.298%. For the determination of protein content, the decrease of protein content obtained by treatment with 11% acetic acid extract showed decrease of protein content 36.656% with Kjeldahl method.

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

PubMed

Guo, Jing; Kang, Yong; Feng, Ying

2017-12-01

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

Heavy metal speciation and toxicity characteristics of tannery sludge

NASA Astrophysics Data System (ADS)

Juel, Md. Ariful Islam; Chowdhury, Zia Uddin Md.; Ahmed, Tanvir

2016-07-01

Heavy metals present in tannery sludge can get mobilized in the environment in various forms and can be a cause for concern for the natural ecosystem and human health. The speciation of metals in sludge provides valuable information regarding their toxicity in the environment and determines their suitability for land application or disposal in landfills. Concentrations of seven heavy metals (Cr, Pb, Cd, Ni, Zn, As and Cu) in tannery sludge were determined to evaluate their toxicity levels. Metal contents ranged over the following intervals: As: 1.52-2.07 mg/kg; Pb: 57.5-67 mg/kg; Cr: 15339-26501 mg/kg; Cu: 261.3-579.5 mg/kg; Zn: 210.2-329.1 mg/kg and Ni: 137.5-141.3 mg/kg (dry weight basis). The concentrations of all heavy metals in the sludge samples were lower compared to EPA guidelines except chromium which was found to be several orders of magnitude higher than the guideline value. Toxicity Characteristics Leaching Procedure (TCLP) test indicated that the leaching potential of chromium was higher compared to the other heavy metals and exceeded the EPA land disposal restriction limits. To quantitatively assess the environmental burden of the chromium associated with tannery sludge, the IMPACT 2002+ methodology was adopted under the SimaPro software environment. Considering the USEPA limit for chromium as the baseline scenario, it was found that chromium in the tannery sludge had 6.41 times higher impact than the baseline in the categories of aquatic ecotoxicity, terrestrial ecotoxicity and non-carcinogens. Chromium has the highest contribution to toxicity in the category of aquatic ecotoxicity while copper is the major contributor to the category of terrestrial ecotoxicity in the tannery sludge.

Effect of methods of preparation on distribution of heavy metals in different size fractions of municipal solid waste composts.

PubMed

Saha, J K; Panwar, N R; Coumar, M Vassanda

2013-11-01

The present study compares the distribution and nature of heavy metals in composts from 12 cities of India, prepared from different types of processed urban solid wastes, namely mixed wastes (MWC), partially segregated wastes (PSWC), and segregated bio-wastes (BWC). Compost samples were physically fractionated by wet sieving, followed by extraction of heavy metals by dilute HCl and NaOH. Bigger particles (>0.5 mm) constituted the major fraction in all three types of composts and had a relatively lower concentration of organic matter and heavy metals, the effect being more pronounced in MWC and PSWC in which a significant portion of the heavy metals was distributed in finer size fractions. Cd, Ni, Pb, and Zn were extracted to a greater extent by acid than by alkali, the difference being greater in MWC, which contained a higher amount of mineral matter. In contrast, Cu and Cr were extracted to a greater extent by dilute alkali, particularly from BWC containing a higher amount of organic matter. Water-soluble heavy metals were generally related to the water-soluble C or total C content as well as to pH, rather than to their total contents. This study concludes that wet sieving with dilute acid can effectively reduce heavy metal load in MWC and PSWC.

Lichens as bioindicators of aerial fallout of heavy metals in Zaria, Nigeria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapu, M.M.; Ipaye, M.M.; Ega, R.A.I.

1991-09-01

Lichens and other epiphytic cryptogams possess efficient ion-exchange mechanisms which enable many species to accumulate airborne metals and which probably contribute to their tolerating metals at concentrations high enough to cause death to other plant species. A direct relationship between the distribution pattern of lichens and the trace metal content of the surrounding air has been demonstrated. The present study used lichens to assess the aerial fallout of heavy metals from traffic in Zaria, northern Nigeria.

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.

Performance of Raphidocelis subcapitata exposed to heavy metal mixtures.

PubMed

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

2017-12-01

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

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

PubMed

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

2018-07-30

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

Zinc oxide nanoparticles (ZnONPs) alleviate heavy metal-induced toxicity in Leucaena leucocephala seedlings: A physiochemical analysis.

PubMed

Venkatachalam, P; Jayaraj, M; Manikandan, R; Geetha, N; Rene, Eldon R; Sharma, N C; Sahi, S V

2017-01-01

The present study describes the role of zinc oxide nanoparticles (ZnONPs) in reversing oxidative stress symptoms induced by heavy metal (Cd and Pb) exposure in Leucaena leucocephala (Lam.) de Wit. Seedling growth was significantly enhanced with the augmentation of ZnONPs following Cd and Pb exposure. Heavy metal accumulations were recorded as 1253.1 mg Cd per kg DW and 1026.8 mg Pb per kg DW for the respective treatments. Results demonstrated that ZnONPs augmentation caused an increase in photosynthetic pigment and total soluble protein contents while a significant decrease in malondialdehyde (MDA-lipid peroxidation) content in leaves. Antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were, in turn, elevated in heavy metal-exposed leaves amended with ZnONPs. The ameliorating effect of ZnO nanoparticles on oxidative stress induced toxicity was also confirmed by the reduced MDA content and the elevated level of antioxidative enzyme activities in leaf tissues of L. leucocephala seedlings. Further, addition of ZnONPs in combination with Cd and Pb metals induced distinct genomic alterations such as presence of new DNA bands and/or absence of normal bands in the RAPD pattern of the exposed plants. This study uniquely suggests a potential role of zinc oxide nanoparticles in the remediation of heavy metal contaminated media. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Heavy Metal Concentrations in Soils and Factors Affecting Metal Uptake by Plants in the Vicinity of a Korean Cu-W Mine.

PubMed

Jung, Myung Chae

2008-04-04

Heavy metal concentrations were measured in soils and plants in and around a copper-tungsten mine in southeast Korea to investigate the influence of past base metal mining on the surface environment. The results of chemical analysis indicate that the heavy metals in soils decreased with distance from the source, controlled mainly by water movement and topography. The metal concentrations measured in plant species generally decreased in the order; spring onions > soybean leaves > perilla leaves » red pepper > corn grains » jujube grains, although this pattern varied moderately between different elements. The results agree with other reports that metal concentrations in leaves are usually much higher than those in grain. Factors influencing the bioavailability of metals and their occurrences in crops were found as soil pH, cation exchange capacity, organic matter content, soil texture, and interaction among the target elements. It is concluded that total metal concentrations in soils are the main controls on their contents in plants. Soil pH was also an important factor. A stepwise linear multiple regression analysis was also conducted to identify the dominant factors influencing metal uptake by plants. Metal concentrations in plants were also estimated by computer-aided statistical methods.

Heavy metals and its chemical speciation in sewage sludge at different stages of processing.

PubMed

Tytła, Malwina; Widziewicz, Kamila; Zielewicz, Ewa

2016-01-01

The analysis of heavy metal concentrations and forms in sewage sludge constitutes an important issue in terms of both health and environmental hazards the metals pose. The total heavy metals concentration enables only the assessment of its contamination. Hence the knowledge of chemical forms is required to determine their environmental mobility and sludge final disposal. Heavy metals speciation was studied by using four-stage sequential extraction BCR (Community Bureau of Reference). This study was aimed at determining the total concentration of selected heavy metals (Zn, Cu, Ni, Pb, Cd, Cr and Hg) and their chemical forms (except for Hg) in sludge collected at different stages of its processing at two municipal Wastewater Treatment Plants in southern Poland. Metals contents in sludge samples were determined by using flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). This study shows that Zn and Cu appeared to be the most abundant in sludge, while Cd and Hg were in the lowest concentrations. The sewage sludge revealed the domination of immobile fractions over the mobile ones. The oxidizable and residual forms were dominant for all the heavy metals. There was also a significant difference in metals speciation between sludges of different origin which was probably due to differences in wastewater composition and processes occurring in biological stage of wastewater treatment. The results indicate a negligible capability of metals to migrate from sludge into the environment. Our research revealed a significant impact of thickening, stabilization and hygienization on the distribution of heavy metals in sludge and their mobility.

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.

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

[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.

Removal of heavy metals from tannery effluents of Ambur industrial area, Tamilnadu by Arthrospira (Spirulina) platensis.

PubMed

Balaji, S; Kalaivani, T; Rajasekaran, C; Shalini, M; Vinodhini, S; Priyadharshini, S Sunitha; Vidya, A G

2015-06-01

The present study was carried out with the tannery effluent contaminated with heavy metals collected from Ambur industrial area to determine the phycoremediation potential of Arthrospira (Spirulina) platensis. Two different concentrations (50 and 100 %) of heavy metals containing tannery effluent treated with A. platensis were analysed for growth, absorption spectra, biochemical properties and antioxidant enzyme activity levels. The effluent treatments revealed dose-dependent decrease in the levels of A. platensis growth (65.37 % for 50 % effluent and 49.32 % for 100 % effluent), chlorophyll content (97.43 % for 50 % effluent and 71.05 % for 100 % effluent) and total protein content (82.63 % for 50 % effluent and 62.10 % for 100 % effluent) that leads to the reduction of total solids, total dissolved solids and total suspended solids. A. platensis with lower effluent concentration was effective than at higher concentration. Treatment with the effluent also resulted in increased activity levels of antioxidant enzymes, such as superoxide dismutase (14.58 units/g fresh weight for 50 % and 24.57 units/g fresh weight for 100 %) and catalase (0.963 units/g fresh weight for 50 % and 1.263 units/g fresh weight for 100 %). Furthermore, heavy metal content was determined using atomic absorption spectrometry. These results indicated that A. platensis has the ability to combat heavy metal stress by the induction of antioxidant enzymes demonstrating its potential usefulness in phycoremediation of tannery effluent.

[Pollution Assessment and Spatial Distribution Characteristics of Heavy Metals in Soils of Coal Mining Area in Longkou City].

PubMed

Liu, Shuo; Wu, Quan-yuan; Cao, Xue-jiang; Wang, Ji-ning; Zhang, Long-long; Cai, Dong-quan; Zhou, Li-yuan; Liu, Na

2016-01-15

The present paper takes the coal mining area of Longkou City as the research area. Thirty-six topsoil (0-20 cm) samples were collected and the contents of 5 kinds of heavy metals were determined, including Cd, As, Ni, Ph, Cr. Geo-statistics analysis was used to analyze the spatial distribution of heavy metals. Principal component analysis (PCA) was used to explore the pollution sources of heavy metals and the degree of heavy metals pollution was evaluated by weighted average comprehensive pollution evaluation method. The results showed that enrichment phenomenon was significant for the 5 kinds of heavy metals. Taking secondary standard of National Environment Quality Standard for Soil as the background value, their exceed standard rates were 72.22%, 100%, 100%, 91.67%, 100%, respectively. Average contents of heavy metals in the soil samples were all over the national standard level two and were 1.53, 11.86, 2.40, 1.31, 4.09 times of the background value. In addition, the average contents were much higher than the background value of the topsoil in the eastern part of Shandong Province and were 9.85, 39.98, 8.85, 4.29, 12.71 times of the background value. According to the semivariogram model, we obtained the nugget-effects of 5 kinds of heavy metals and their values were in the order of As (0.644) > Cd (0.627) > Cr (0.538) > Ni (0.411) > Pb (0.294), all belonging to moderate spatial correlation. On the whole, the central part of the Sangyuan Coal Mine and its surrounding areas were the most seriously polluted, while the pollution of heavy metals in the east and west of the study area was relatively light. Principal component analysis suggested that the enrichment of Cd, As, Ni, Cr was due to irrigation of wastewater, the discharge of industry and enterprise, and the industrial activity. Automobile exhaust and coal combustion were the main pollution sources of Pb. The single-factor assessment of heavy metals pollution showed that the degree of different heavy metals

[Correlativity study of the distribution of soil magnetic susceptibility and the heavy metal contents in Xi'an City].

PubMed

Chen, Xiu-Duan; Lu, Xin-Wei; Yang, Guang

2013-03-01

The magnetic susceptibility and the concentrations of Co, Cr, Cu, Pb, Sn, Sr and Ba in topsoil samples from Xi'an City were measured to study their spatial distribution and their correlation in this study. The results show that the concentrations of all measured heavy metals are higher than their background values in Cinnamon topsoil, which is the main soil type of Xi'an City. The heavy metals concentrations and the magnetic susceptibility of the studied samples display moderate variance. Co, Cr, Cu, Pb, Sn, Sr and Ba are significantly positively correlated with low-frequency magnetic susceptibility, while are significantly negatively correlated with frequency susceptibility. The spatial distribution of low-frequency magnetic susceptibility is identical with the concentrations of Pb and Cu. However, the spatial variation of frequency magnetic susceptibility is different from the concentrations of Co, Cr and Ba. The pollution assessment results show that the heavy metal pollution in topsoil of Xi'an City is moderate. The spatial contribution of the pollution load index was significantly correlated with the magnetic susceptibility of topsoil in Xi'an City. Therefore, soil magnetic susceptibility can be used as an effective monitoring means for heavy metal pollution in urban soil.

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

PubMed

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

2007-09-01

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

Analyses of Mineral Content and Heavy Metal of Honey Samples from South and East Region of Turkey by Using ICP-MS.

PubMed

Kılıç Altun, Serap; Dinç, Hikmet; Paksoy, Nilgün; Temamoğulları, Füsun Karaçal; Savrunlu, Mehmet

2017-01-01

The substantial of mineral ingredients in honey may symbolize the existence of elements in the plants and soil of the vicinity wherein the honey was taken. The aim of this study was to detect the levels of 13 elements (Potassium (K), Sodium (Na), Calcium (Ca), Iron (Fe), Zinc (Zn), Cadmium (Cd), Copper (Cu), Manganese (Mn), Lead (Pb), Nickel (Ni), Chromium (Cr), Aluminum (Al), and Selenium (Se)) in unifloral and multifloral honey samples from south and east regions of Turkey. Survey of 71 honey samples from seven different herbal origins, picked up from the south and east region of Turkey, was carried out to determine their mineral contents during 2015-2016. The mineral contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The most abundant minerals were K, Na, and Ca ranging within 1.18-268 ppm, 0.57-13.1 ppm, and 0.77-4.5 ppm, respectively. Zn and Cu were the most abundant trace element while Pb, Cd, Ni, and Cr were the lowest heavy metals in the honey samples surveyed, with regard to the concentrations of heavy metals such as Zn, Cu, Pb, Cd, Ni, and Cr suggested and influence of the botanical origin of element composition. Geochemical and geographical differences are probably related to the variations of the chemical components of honey samples.

[Pollution Evaluation and Risk Assessment of Heavy Metals from Atmospheric Deposition in the Parks of Nanjing].

PubMed

Wang, Cheng; Qian, Xin; Li, Hui-ming; Sun, Yi-xuan; Wang, Jin-hua

2016-05-15

Contents of heavy metals involving As, Cd, Cr, Cu, Ni, Pb and Zn from atmospheric deposition in 10 parks of Nanjing were analyzed. The pollution level, ecological risk and health risk were evaluated using Geoaccumulation Index, Potential Ecological Risk Index and the US EPA Health Risk Assessment Model, respectively. The results showed that the pollution levels of heavy metals in Swallow Rock Park, Swallow Rock Park and Mochou Lake Park were higher than the others. Compared to other cities such as Changchun, Wuhan and Beijing, the contents of heavy metals in atmospheric deposition of parks in Nanjing were higher. The evaluation results of Geoaccumulation Index showed that Pb was at moderate pollution level, Zn and Cu were between moderate and serious levels, while Cd was between serious and extreme levels. The ecological risk level of Cd was high. The assessment results of Health Risk Assessment Model indicated that there was no non-carcinogenic risk for all the seven heavy metals. For carcinogenic risk, the risks of Cd, Cr and Ni were all negligible (Risk < 1 x 10⁻⁶), whereas As had carcinogenic risk possibility but was considered to be acceptable (10⁻⁶ < Risk < 10⁻⁴).

[Distribution patterns and pollution assessments of heavy metals in the Spartina alterniflora salt-marsh wetland of Rudong, Jiangsu province].

PubMed

Zhang, Long-Hui; Du, Yong-Fen; Wang, Dan-Dan; Gao, Shu; Gao, Wen-Hua

2014-06-01

To understand the ecological impact of Spartina alterniflora on the coastal wetland environment, field survey was carried out in July, 2010, over the intertidal areas of Rudong coast, Jiangsu province; sediment samples were collected from a series of stations with different conditions of vegetation cover and S. alterniflora growth. The contents of eight heavy metals, together with sediment composition and total organic carbon were analyzed to reveal the distribution patterns of the heavy metals. Environmental quality status was evaluated using both the index of geoaccumulation (I(geo)) and the index of the Håkanson ecological risk. The analytical results showed that the average contents of Pb, Cd, As, Hg, Cr, Cu, Ni and Zn were below the standard for the Category I sediment quality, among which Cd, Hg, Ni and Zn exceeded the sediment background value of the region. On the whole, the contents of eight heavy metals in vegetation areas were higher than those associated with the adjacent bare flat areas. These data sets indicate a non-polluted condition in term of I(geo) estimation; however, a critical state of low to moderate degrees of pollution and a low level of risk were deduced according to the index of the Håkanson potential ecological risk. Both indices suggested that the pollution level of Hg and Cd were the highest among the eight metals measured. Along the transection from seaward to landward, the contents of As, Cu and Hg, their indices of I(geo) and Håkanson ecological risk all showed an increasing tread, in accordance with the condition of vegetation cover. Along the coastline with S. alterniflora being distributed in patchiness, all metal contents and their ecological risk level values for the marshes were higher than those for the unvegetated sediments nearby; moreover, except for Hg, other seven metals exhibited relatively low values than those in the shore-normal section with a better S. alterniflora growth. These findings indicate that S

Pollution Assessment and Sources Identification of Heavy Metals in Surface Sediments from the Nantaizi Lake, Middle China

NASA Astrophysics Data System (ADS)

Ma, Jinlong; Li, Fei; Jia, Xiaolin; Zhang, Jingdong

2018-01-01

The total contents of heavy metal elements including Cr, Cd, Cu, Zn, Pb and As were investigated in sediments from the Nantaizi Lake in Hanyang district of Wuhan. The heavy metal pollution level of Nantaizi Lake was calculated by potential ecological risk index and the main sources of pollutants were researched by correlation analysis and principal component analysis. The results show that heavy metal concentration of Nantaizi Lake sediments is within the Chinese Environmental Quality Standard for Soils (GB 15618-1995) level-II standard limitation. According to the result of potential ecological risk index, ecological hazard rank of heavy metal element of Nantaizi Lake sediments is: Cd>Cu>As>Pb>Zn>Cr, and whole water environment of lake is slightly polluted. Through correlation analysis and principal component analysis, it is found that industrial sewage and domestic wastewater in human activities are the main contributors to heavy metal sources of Nantaizi Lake, and chemical processes, such as endogenous microbial activities of lake etc., also affect heavy metal sources in sediments simultaneously.

Field reconnaissance and estimation of petroleum hydrocarbon and heavy metal contents of soils affected by the Ebocha-8 oil spillage in Niger Delta, Nigeria.

PubMed

Osuji, Leo C; Onojake, Chukunedum M

2006-04-01

Field reconnaissance of the Ebocha-8 oil spill-affected site at Obiobi/Obrikom in the Niger Delta region of Nigeria was carried out to assess the extent of damage to the terrestrial ecosystem and delimit the epicenter of oil spillage. Following three successive reconnaissance surveys, the area to be sampled was delimited (200 x 200 m2), and soil samples were collected using the grid method from three replicate quadrats at two depths, surface (0-15 cm) and subsurface (15-30 cm). A geographically similar area located 50 m adjacent to the oil-polluted area was used as a reference (control) site. Total hydrocarbon content (THC) and heavy metal concentrations were later determined in the laboratory by extraction and spetrophotemetric techniques. Generally, the THC of soils at surface and subsurface depths of the oil-polluted plots was 2.06 x 10(4) +/- 4.97 x 10(3) mg/kg and 1.67 x 10(3) +/- 3.61 x 10(2) mg/kg soil, respectively, (no overlap in standard errors at 95% confidence limit) while concentrations of heavy metals(Pb, Cd, V, Cu and Ni) were enhanced, especially at the surface. The high levels of THC and heavy metals may predispose the site, which hitherto served as arable agricultural land, to impaired fertility and possible conflagration. When concentrations of heavy metals reach the levels obtained in this study, they may become toxic to plants or possibly bio-accumulate, thus leading to toxic reactions along the food chain. While the spilled-oil may have contributed to the enhanced levels of the metals in the affected soils, physico-chemical properties of the soils, mobility of metals, and the intense rainfall and flooding that preceded the period of study may have also contributed in part to their enhanced concentrations. The presence of high hydrocarbon content may cause oxygen deprivation, which may result in the death of soil fauna by asphyxiation. There is, therefore, an urgent need to clear the affected site of these excess hydrocarbon deposits so as to

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 CaCl 2 , 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.

[Pollution by heavy metals in the petrochemical sewage waters of the sea area of Daya Bay and assessment on potential ecological risks].

PubMed

Xu, Shan-Nan; Li, Chun-Hou; Xu, Jiao-Jiao; Xiao, Ya-Yuan; Lin, Lin; Huang, Xiao-Ping

2014-06-01

This study aimed to gain a clear understanding on the status of pollution by heavy metals in the petrochemical sewage and the potential ecological risk caused by heavy metal pollution in the sea area of Daya Bay. The contents and spatial distributions of heavy metals including Zn, Pb, Cu, Cd, Cr, As and Hg in seawater, sediment and fishes collected from Daya Bay were analyzed. The comprehensive pollution index (CPI) and ecological risk indexes (ERIs) were used to evaluate the contaminated severity and potential ecological risks of heavy metals in seawater and sediment. The results showed that the contents of these heavy metals, except for those of Zn and Pb, in several stations set in Daya Bay from 2011 to 2012 were relatively low, which were lower than the quality standard of class I according to the China National Standard Criteria for Seawater Quality, suggesting that the seawater in Daya Bay has not been polluted yet by these heavy metals. The average CPI of heavy metals in seawater during flooding season (0.72) was higher than that during dry season (0.38) whereas the average CPI of heavy metals in sediment during dry season (7.77) was higher than that during flooding season (5.70). Hg was found to be the primary contaminating heavy metal in sediment during dry season, which was followed by As and Zn whereas during flooding season, Hg was the primary contaminating metal in sediment, followed by Zn and Cu. The contents of these 7 heavy metals in fishes collected from the surveyed areas were lower than those of the standard requirements. A correlation analysis indicated that there were significant differences in the correlations between the midst of the heavy metals in sea water and the different periods. The ERIs of heavy metals in sediment during dry season (129.20) was higher than that during flooding season (102.86), and 25% of the sampling sites among all stations were under the risk of high-level alarm. The potential ERIs of heavy metals in sediment in

Effects of Application of NTA and EDTA on Accumulation of Soil Heavy Metals in Chrysanthemum

NASA Astrophysics Data System (ADS)

Bai, Weiyang

2018-02-01

In order to find out the effect of non-bio chelating agent EDTA and bio-chelating agent NTA on soil heavy metal pollution, the effects of different ratio of chelating agent NTA and EDTA on soil heavy metals (Pb, Cu and Cd ), the effects of chelating on content of chlorophyll and vitamin C and the degree of soil nutrient loss were evaluated. The results showed: that the contents of Pb and Cd were the highest in the roots of Chrysanthemum in the treatment (EDTA / NTA = 2: 1). The treatment (EDTA / NTA = 1: 1) was the best chelating agent ratio for the synergistic effect, which can significantly promoted the Chrysanthemum on heavy metal Cu uptake and transport to aboveground. Chrysanthemum were inhibited by all chelating agents treatments, while the content of chlorophyll and vitamin C of the Chrysanthemum physiological indexes were reduced. In the treatment (EDTA = 1), chlorophyll SPAD, vitamin C content reached a minimum of 36 and 38mg · 100g-1, respectively. The nutrient element TN in the leachate were gradually decreased with the time, and the tenth day was significantly lower than the leaching rate of the first day (p <0.05) in the treatments (NTA = 1, EDTA / NTA = 1: 2). The nutrient element TN was decreased most, reaching 51.6%, and the activation effect was decreased significantly in the fifteenth day in treatment (NTA = 1), Treatment(EDTA / NTA = 1: 1)> treatment (EDTA = 1) >treatment (EDTA / NTA = 2: 1) >treatment (EDTA / NTA = 1: 2)> treatment (NTA = 1). Treatment (EDTA / NTA = 2: 1) was recommended for the chelating agent ratio with the better physiological parameters, the more heavy metal extraction and the less nitrogen and phosphorus loss

Heavy Metal, Religiosity, and Suicide Acceptability.

ERIC Educational Resources Information Center

Stack, Steven

1998-01-01

Reports on data taken from the General Social Survey that found a link between "heavy metal" rock fanship and suicide acceptability. Finds that relationship becomes nonsignificant once level of religiosity is controlled. Heavy metal fans are low in religiosity, which contributes to greater suicide acceptability. (Author/JDM)

Distributing Characteristics of Heavy Metal Elements in A Tributary of Zhedong River in Laowangzhai Gold Deposit, Yunnan (China): An Implication to Environmentology from Sediments

NASA Astrophysics Data System (ADS)

Yang, Shuran; Danĕk, Tomáš; Yang, Xiaofeng; Cheng, Xianfeng

2016-10-01

Five heavy metal contents from five sediments and seven sediment profiles in an upstream reach of Zhedong river in Laowangzhai gold deposit were investigated in this research, along with analysis of the horizontal distribution, the surface distribution, the vertical distribution and the interlayer distribution of five heavy metal contents: arsenic (As), mercury (Hg), copper (Cu), lead (Pb) and zinc (Zn). The potential ecological risk of five heavy metals was evaluated to help understanding pollution control of Laowangzhai deposit.

Heavy metal contamination from geothermal sources.

PubMed Central

Sabadell, J E; Axtmann, R C

1975-01-01

Liquid-dominated hydrothermal reservoirs, which contain saline fluids at high temperatures and pressures, have a significant potential for contamination of the environment by heavy metals. The design of the power conversion cycle in a liquid-dominated geothermal plant is a key factor in determining the impact of the installation. Reinjection of the fluid into the reservoir minimizes heavy metal effluents but is routinely practiced at few installations. Binary power cycles with reinjection would provide even cleaner systems but are not yet ready for commercial application. Vapor-dominated systems, which contain superheated steam, have less potential for contamination but are relatively uncommon. Field data on heavy metal effluents from geothermal plants are sparse and confounded by contributions from "natural" sources such as geysers and hot springs which often exist nearby. Insofar as geothermal power supplies are destined to multiply, much work is required on their environmental effects including those caused by heavy metals. PMID:1227849

Heavy metal contamination from geothermal sources.

PubMed

Sabadell, J E; Axtmann, R C

1975-12-01

Liquid-dominated hydrothermal reservoirs, which contain saline fluids at high temperatures and pressures, have a significant potential for contamination of the environment by heavy metals. The design of the power conversion cycle in a liquid-dominated geothermal plant is a key factor in determining the impact of the installation. Reinjection of the fluid into the reservoir minimizes heavy metal effluents but is routinely practiced at few installations. Binary power cycles with reinjection would provide even cleaner systems but are not yet ready for commercial application. Vapor-dominated systems, which contain superheated steam, have less potential for contamination but are relatively uncommon. Field data on heavy metal effluents from geothermal plants are sparse and confounded by contributions from "natural" sources such as geysers and hot springs which often exist nearby. Insofar as geothermal power supplies are destined to multiply, much work is required on their environmental effects including those caused by heavy metals.

Irrigation water quality influences heavy metal uptake by willows in biosolids.

PubMed

Laidlaw, W Scott; Baker, Alan J M; Gregory, David; Arndt, Stefan K

2015-05-15

Phytoextraction is an effective method to remediate heavy metal contaminated landscapes but is often applied for single metal contaminants. Plants used for phytoextraction may not always be able to grow in drier environments without irrigation. This study investigated if willows (Salix x reichardtii A. Kerner) can be used for phytoextraction of multiple metals in biosolids, an end-product of the wastewater treatment process, and if irrigation with reclaimed and freshwater influences the extraction process. A plantation of willows was established directly onto a tilled stockpile of metal-contaminated biosolids and irrigated with slightly saline reclaimed water (EC ∼2 dS/cm) at a wastewater processing plant in Victoria, Australia. Biomass was harvested annually and analysed for heavy metal content. Phytoextraction of cadmium, copper, nickel and zinc was benchmarked against freshwater irrigated willows. The minimum irrigation rate of 700 mm per growing season was sufficient for willows to grow and extract metals. Increasing irrigation rates produced no differences in total biomass and also no differences in the extraction of heavy metals. The reclaimed water reduced both the salinity and the acidity of the biosolids significantly within the first 12 months after irrigation commenced and after three seasons the salinity of the biosolids had dropped to <15% of initial values. A flushing treatment to remove excess salts was therefore not necessary. Irrigation had an impact on biosolids attributes such as salinity and pH, and that this had an influence on metal extraction. Reclaimed water irrigation reduced the biosolid pH and this was associated with reductions of the extraction of Ni and Zn, it did not influence the extraction of Cu and enhanced the phytoextraction of Cd, which was probably related to the high chloride content of the reclaimed water. Our results demonstrate that flood-irrigation with reclaimed water was a successful treatment to grow willows in a

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.

The mobility and distribution of heavy metals during the formation of first cycle red beds.

USGS Publications Warehouse

Zielinski, R.A.; Bloch, S.; Walker, T.R.

1983-01-01

Analysis of the heavy metal content in a Holocene-Pliocene red bed sequence near San Felipe in N Baja California, Mexico, has yielded new information on the mobility and distribution of these metals during ageing of iron oxyhydroxides from the amorphous to the crystalline state. Whole-rock samples (27) and a series of successive leachates were analysed for V, Al, Cr, Mn, Fe, Co, Ni, Cu and Zn by ICP spectrometry and for U by a delayed neutron technique. These data are supported by a variety of other mineralogical and petrographical observations. The results indicate that the metal content of the samples is predominantly inherited from the constituent detrital minerals. Reddening of the whole-rock samples does not promote major open-system migration of the heavy metals; rather, contained metals redistribute themselves on an intergranular scale, moving from detrital mineral hosts to the secondary iron oxides. The amount of secondary iron oxides and the fraction of whole-rock metals associated with these oxides increase during red-bed development. In addition, the abundance of well- crystallized iron oxides increases during this period. Differences in the leaching efficiency for various metals are related to differences in metal site distribution and intergranular permeability. Inferred conditions for rapid vs limited removal of metals from red beds are summarized. It is suggested that developed red beds which are well flushed by suitable pore fluids may be sources of significant quantities of heavy metals. -J.E.S.

Evaluation of silkworm excrement and mushroom dreg for the remediation of multiple heavy metal/metalloid contaminated soil using pakchoi.

PubMed

Wang, Ruigang; Guo, Junkang; Xu, Yingming; Ding, Yongzhen; Shen, Yue; Zheng, Xiangqun; Feng, Renwei

2016-02-01

The economical, environmental friendly and efficient materials to remediate the pollution with multiple heavy metals and metalloids are scarce. Silkworm excrement (SE) and mushroom dregs (MD) are two types of agricultural wastes, and they are widely used to improve the soil fertility in many regions of China. A pot experiment with sixteen treatments was set up to assess the possibility of using SE and MD to stabilize heavy metals and metalloids and reduce their uptake in pakchoi cultivated in slightly contaminated soils with arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn). The results showed that the single addition of SE obviously stimulated the growth of pakchoi, reduced the contents of all tested heavy metals and metalloids in the edible part of pakchoi and availability of Zn and Cd in soil. The single MD treatment showed an inferior ability to enhance the growth and reduce the contents of heavy metals and metalloids in the edible part of pakchoi. The combined utilization of SE and MD appeared not to show better effects than their individual treatment when using them to remediate this contaminated soil. Some potential mechanisms on the stimulation on pakchoi growth and decreasing the accumulation of heavy metals and metalloids in pakchoi subjected to SE were suggested, including: (1) enhancing soil pH to impact the availability of heavy metals and metalloids; (2) improve the fertility of soil; (3) sulfhydryl groups of organic materials in SE play a role in conjugating heavy metals and metalloids to affect their availability in soil; and (4) stimulating the growth of pakchoi so as to show a "dilution effect" of heavy metals and metalloids. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Spatio-temporal distribution and environmental risk of sedimentary heavy metals in the Yangtze River Estuary and its adjacent areas.

PubMed

Chen, Bin; Liu, Jian; Qiu, Jiandong; Zhang, Xilin; Wang, Shuang; Liu, Jinqing

2017-03-15

Twenty-five surface sediments and one sediment core sample were collected from the study area. Grain size, major elements, and heavy metals were determined. The content of fine-grained sediments (silt and clay), as well as the concentrations of major elements and heavy metals, showed seaward decreasing trends, with high content in the coastal areas of the East China Sea (ECS) and south west of Jeju Island. Low enrichment factor (EF) and geoaccumulation index (Igeo) values were found, indicating that the ecological risk of heavy metals was low. The EF values obtained from the high-resolution sedimentary records of heavy metals in the Yangtze River Estuary could be divided into Stage 1 (1950s to the late 1970s) and Stage 2 (late 1970s to the current sampling day), which coincided with economic development of the Yangtze River Basin, implementation of environmental protection, and impoundment of the Three Gorges Dam. Copyright © 2016. Published by Elsevier Ltd.

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

Resistance of black soldier fly (Diptera: Stratiomyidae) larvae to combined heavy metals and potential application in municipal sewage sludge treatment.

PubMed

Cai, Minmin; Hu, Ruiqi; Zhang, Ke; Ma, Shiteng; Zheng, Longyu; Yu, Ziniu; Zhang, Jibin

2018-01-01

Treating municipal sewage sludge (MSS) sustainably and economically in China remains a challenge because of risks associated with the heavy metals it contains. In this study, black solider fly larvae (BSFL) were used for MSS treatment. The resistance of larvae to combined heavy metals and their potential use in conversion of MSS were investigated. The results indicated that seven MSS samples contained large amounts of heavy metals, with the lead and nickel contents of several samples exceeding Chinese national discharge standards. BSFL were highly tolerant to an artificial diet spiked with combined heavy metals. Principal component analysis revealed that high concentrations of lead, nickel, boron, and mercury potentially interfered with larval weight gain, while zinc, copper, chromium, cadmium, and mercury slightly reduced larval survival. The addition of chicken manure and wheat bran as co-substrates improved the conversion process, which was influenced by the nature and amount of added co-substrate and especially the quantity of nitrogen added. With the amended substrate, the BSFL accumulated heavy metals into their bodies but not into extracted larval oil. The heavy metal content of the treatment residue was lower than that considered safe for organic-inorganic compound fertilizers standards in China and the harvested larvae could be used as a source of oil for industrial application.

Determination of heavy metals in the common smokeless tobacco afzal in oman.

PubMed

Al-Mukhaini, Nawal; Ba-Omar, Taher; Eltayeb, Elsadig; Al-Shehi, Aisha

2014-08-01

Afzal is an illegally sold smokeless tobacco product (STP) commonly used by youths and teenagers in Oman. The aim of this study was to analyse the composition of Afzal, also commonly known as sweekah, as it is believed to contain many carcinogens and toxic components. In particular, Afzal's heavy metal content includes cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni). This study was conducted between March and June 2013. Three samples of Afzal were first dried and then ground to form a homogenous powder. The powder was digested prior to the heavy metal analysis by inductively coupled plasma-mass spectrometry (ICP-MS). Afzal was shown to have high levels of all heavy metals except for Ni and Pb, which were detected in quantities below acceptable international limits. The concentrations of the tested metals were 15.75 μg/g, 1.85 μg/g, 1.62 μg/g and 1.57 μg/g for Cr, Cd, Pb and Ni, respectively. The estimated daily intake of heavy metals from Afzal was below the maximum permissible limit accepted by the Food and Agriculture Organization and World Health Organization, except for Cr and Ni which were found to be dangerously elevated when compared with international standards. The results of this study showed that Afzal contains a number of heavy metals that may cause health problems. Therefore, urgent regulation of the illegal sale of Afzal is needed at the national level in Oman along with a campaign to address public health education and awareness of Afzal and its health risks.

Concentration of heavy metals in ash produced from Lithuanian forests

NASA Astrophysics Data System (ADS)

Baltrenaite, Edita; Pereira, Paulo; Butkus, Donatas; Úbeda, Xavier

2010-05-01

Wood ash contains important amounts of heavy metals. This quantity depends on burned specie, temperature of exposition and heat duration time. Due the high mineralization imposed by the temperatures, ash is used as lime product in agriculture and forests. Also, after a forest fire large quantities of ash are produced and distributed in soil surface. This mineralized organic matter can induce important environmental problems, including soil toxicity provoked by heavy metals leachates from ash. There is an extensive literature about heavy metals contents on ash in different species. However, it recently highlighted that the same species placed in different environments can respond diversely to same temperatures. This question is of major importance because temperature effects on severity can be a function of the plant communities instead of specie characteristics. These findings add a higher degree of complexity in the understanding of temperature effects on ash composition and consequent availability of heavy metals. The aim of this study is to compare the ash chemical heavy metal composition, Cobalt (Co), Chromium (Cr), Cooper (Cu), Silver (Ag), Lead (Pb), Nickel (Ni), Manganese (Mn) and Zinc (Zn), from Pinus sylvestris and Betula pendula, collected in key and representative areas of Lithuanian forests, located in southern, coastal and central part. Samples were collected from alive trees, taken to laboratory and air dried. Subsequently were crushed and submitted to muffle furnace at temperature of 550°C during two hours. The ash samples were digested and in a HNO3-HCl solution and then analysed with AAS. Comparisons between species and sites were performed with a Non-parametric one-way ANOVA‘s on rank transformed data followed by Tukey‘s HSD, significant at a p<0.05. Results showed significant difference between Co and Ag concentrations between Pinus sylvestris and Betula pendula. Also, significantly different concentrations of Pb, Cu, Ni and Mn were

[Using sequential indicator simulation method to define risk areas of soil heavy metals in farmland.

PubMed

Yang, Hao; Song, Ying Qiang; Hu, Yue Ming; Chen, Fei Xiang; Zhang, Rui

2018-05-01

The heavy metals in soil have serious impacts on safety, ecological environment and human health due to their toxicity and accumulation. It is necessary to efficiently identify the risk area of heavy metals in farmland soil, which is of important significance for environment protection, pollution warning and farmland risk control. We collected 204 samples and analyzed the contents of seven kinds of heavy metals (Cu, Zn, Pb, Cd, Cr, As, Hg) in Zengcheng District of Guangzhou, China. In order to overcame the problems of the data, including the limitation of abnormal values and skewness distribution and the smooth effect with the traditional kriging methods, we used sequential indicator simulation method (SISIM) to define the spatial distribution of heavy metals, and combined Hakanson index method to identify potential ecological risk area of heavy metals in farmland. The results showed that: (1) Based on the similar accuracy of spatial prediction of soil heavy metals, the SISIM had a better expression of detail rebuild than ordinary kriging in small scale area. Compared to indicator kriging, the SISIM had less error rate (4.9%-17.1%) in uncertainty evaluation of heavy-metal risk identification. The SISIM had less smooth effect and was more applicable to simulate the spatial uncertainty assessment of soil heavy metals and risk identification. (2) There was no pollution in Zengcheng's farmland. Moderate potential ecological risk was found in the southern part of study area due to enterprise production, human activities, and river sediments. This study combined the sequential indicator simulation with Hakanson risk index method, and effectively overcame the outlier information loss and smooth effect of traditional kriging method. It provided a new way to identify the soil heavy metal risk area of farmland in uneven sampling.

Leaching heavy metals from the surface soil of reclaimed tidal flat by alternating seawater inundation and air drying.

PubMed

Guo, Shi-Hong; Liu, Zhen-Ling; Li, Qu-Sheng; Yang, Ping; Wang, Li-Li; He, Bao-Yan; Xu, Zhi-Min; Ye, Jin-Shao; Zeng, Eddy Y

2016-08-01

Leaching experiments were conducted in a greenhouse to simulate seawater leaching combined with alternating seawater inundation and air drying. We investigated the heavy metal release of soils caused by changes associated with seawater inundation/air drying cycles in the reclaimed soils. After the treatment, the contents of all heavy metals (Cd, Pb, Cr, and Cu), except Zn, in surface soil significantly decreased (P < 0.05), with removal rates ranging from 10% to 51%. The amounts of the exchangeable, carbonate, reducible, and oxidizable fractions also significantly decreased (P < 0.05). Moreover, prolonged seawater inundation enhanced the release of heavy metals. Measurement of diffusive gradients in thin films indicated that seawater inundation significantly increased the re-mobility of heavy metals. During seawater inundation, iron oxide reduction induced the release of heavy metals in the reducible fraction. Decomposition of organic matter, and complexation with dissolved organic carbon decreased the amount of heavy metals in the oxidizable fraction. Furthermore, complexation of chloride ions and competition of cations during seawater inundation and/or leaching decreased the levels of heavy metals in the exchangeable fraction. By contrast, air drying significantly enhanced the concentration of heavy metals in the exchangeable fraction. Therefore, the removal of heavy metals in the exchangeable fraction can be enhanced during subsequent leaching with seawater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heavy metals in bullfrog (Rana catesbeiana) tadpoles: Effects of depuration before analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, J.; Snodgrass, J.

1998-11-01

Although tadpoles may well be excellent organisms to use as bioindicators of heavy metal contamination, the relationship of deposition in the body compared to the tail, and the effect of sediments or other debris in the digestive tract on heavy metal concentrations is unknown. The authors examined the effect of experimental depuration of bullfrog (Rana catesbeiana) tadpoles on heavy metal and selenium concentrations in intact tadpoles, as well as their bodies and tails. They defined depuration in this experiment as allowing defecation as an elimination process for intestinal contents. The authors maintained wild-caught tadpoles in clean water for 0, 24,more » 48, and 72 h to determine the effects of clearing on heavy metal concentrations. They also examined the concentrations of heavy metals in the whole body and digestive tract separately. The authors test the null hypotheses that no differences occur in metals as a function of time in uncontaminated water, and that no differences occur in metal concentrations in the body compared to the tail and to the digestive tract. They rejected these hypotheses based on regression models. Variance in concentrations of chromium (77%) and lead (70%) were explained by part and clearing time; for manganese (80%), mercury (64%), selenium (28%), and cadmium (25%) the variation was explained only by body part; for arsenic (53%), the variation was explained by part, clearing time, and weight of the various parts. For those metals in which clearing time explained part of the variation, metal concentrations in both the body and tail decreased after 24 and 48 h, but increased slightly thereafter. Clearing, however, did not greatly decrease metal concentrations in either the body or tail. These data suggest that for some metals (mercury, manganese, cadmium, selenium), clearing has no effect, and for others the effect is slight. For fresh tadpoles, however, the digestive tract contained significantly higher concentrations of all metals

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

PubMed

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

2005-01-01

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

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.

Vertical profile, contamination assessment, and source apportionment of heavy metals in sediment cores of Kaohsiung Harbor, Taiwan.

PubMed

Chen, Chih-Feng; Ju, Yun-Ru; Chen, Chiu-Wen; Dong, Cheng-Di

2016-12-01

Six sediment cores collected at the Kaohsiung Harbor of Taiwan were analyzed to evaluate their vertical profiles, enrichments, accumulations, and source apportionments of heavy metals. This was performed to investigate any potential ecological risks posed by heavy metals. Results indicated that the mean heavy metal content (mg kg -1 ) in the six sediment cores was as follows: Hg (0.4-6.4), Cd (<0.05-2.4), Cr (18-820), Cu (16-760), Pb (31-140), and Zn (76-1900). The patterns of heavy metal content in the sediment cores differed substantially among the four river mouths. However, the vertical profiles of metals were relatively stable, indicating that wastewater has the constant characteristics and has been discharged into the rivers for a long period of time. Results of pollution assessment of enrichment factor, geo-accumulation index, and pollution load index revealed that river mouths experience severe enrichment, strong accumulation, and high contamination from the primary heavy metals. It was not consistent in the assessment results of mean effect range median quotient, potential ecological risk index, and total toxic unit method. Potential ecological risks caused by Hg in the sediments at Canon River and Love River mouths on aquatic organisms were extremely high. The estimates derived from the receptor modeling of multiple linear regression of the absolute principal component scores indicated that the contributions of the composite heavy metals derived from the Canon River and the Love River on the potential toxicity and risks to the water environment of Kaohsiung Harbor were highest, followed by those derived from Salt River and Jen-Gen River. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Heavy metals distribution characteristics and risk assessment of water below an electroplating factory].

PubMed

Hang, Xiao-Shuai; Wang, Huo-Yan; Zhou, Jian-Min

2008-10-01

Surface water and shallow groundwater within the flow of an electroplating factory was analyzed in order to study the resulting impact. The analysis method of ICP-AES was used to analyze content of zinc, manganese, chromium, copper and nickel in surface water and groundwater samples. The results indicate acidic pollutants of zinc, manganese, chromium, copper and nickel were discharged from the factory with concentrations of 1.34, 3.77, 28.1, 6.40 and 9.37 mg x L(-1), respectively; and pH was 2.32. They all exceeded permissible levels according to Integrated Wastewater Discharge Standard except zinc. Factory discharge is responsible for the longitudinal distribution characteristics of heavy metals in the stream water downstream from the factory. Heavy metals variations in the well water do not suggest they were affected by heavy metals in the stream, indicating that the migration rates of heavy metals in soils were relatively low. Risk assessment shows surface water quality significantly deteriorated. Nickel and manganese in the stream water exceeded the standard levels seriously, and chromium and copper in some samples were also above Grade III standard levels according to Environmental Quality Standard for Surface Water. Moreover, all studied heavy metals in 14 groundwater samples measured within drinking water standard, except manganese in 4 groundwater samples, which were Grade IV according to Quality Standard for Ground water.

Beneficial of Coriander Leaves (Coriandrum sativum L.) to Reduce Heavy Metals Contamination in Rod Shellfish

NASA Astrophysics Data System (ADS)

Winarti, S.; Pertiwi, C. N.; Hanani, A. Z.; Mujamil, S. I.; Putra, K. A.; Herlambang, K. C.

2018-01-01

Contamination of heavy metals in certain levels of food can disrupt human health. Heavy metals have toxic properties, cannot be overhauled or destroyed by living organisms, can accumulate in the body of organisms including humans, either directly or indirectly. Heavy metal Hg, Cd, Cr is a very toxic metals (can result in death or health problems that are not recovered in a short time), while heavy metal Co, Pb, Cu toxicity is moderate (can lead to both recoverable and non-recoverable health problems in a relatively long time). Hence the heavy metal contaminating the food must be eliminated or reduced to a safe level. One effort was use coriander leaves to reduce the contamination of heavy metals in fish/shellfish. The objective of the research was to prove the extract of coriander leaves can reduce heavy metal contamination of Pb, Hg and Cu in rod shellfish (lorjuk). The treatment of this research was long soaking in coriander leaves extract that were 0, 30, 60 and 90 minutes. The results showed that the longer time of soaking can decrease Pb level from 4.4 ± 0.424 ppb to 1.7 ± 0.5 ppb, Hg level from 4.11± 0.07 to 1.12± 0.6 ppb, and Cu level from 433.7 ± 0.1 ppb to 117 ± 0.78 ppb. Protein content not significant decrease in rod shellfish (lorjuk) after 90 minutes soaking time, that was from 28.56 ± 0.403% to 26,625 ± 0.19%.

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

PubMed

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

2017-01-15

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

Heavy Metal Contamination in the Surface Sediments of Representative Limnetic Ecosystems in Eastern China

PubMed Central

Tang, Wenzhong; Shan, Baoqing; Zhang, Hong; Zhang, Wenqiang; Zhao, Yu; Ding, Yuekui; Rong, Nan; Zhu, Xiaolei

2014-01-01

A comprehensive analysis of heavy metal pollution was conducted in the representative limnetic ecosystems of eastern China, which are subject to rapid economic development and population growth. The results demonstrated that the average contents with standard deviations of Cd, Cr, Cu, Ni, Pb and Zn in the surface sediments were 0.925 ± 0.936, 142 ± 46.8, 54.7 ± 29.1, 60.5 ± 21.6, 61.9 ± 36.0 and 192 ± 120 mg/kg dry wt., respectively, and that higher values were mainly observed in the southern portion of the study area, especially in the basins of Southeast Coastal Rivers (SCRB) and the Zhu River (ZRB). The six heavy metals in the surface sediments all had anthropogenic origins. In addition, the limnetic ecosystems, especially in the southern portion of the study area were found to be polluted by heavy metals, especially Cd. Overall, two hotspots of heavy metal pollution in the limnetic ecosystems of eastern China were found, one that consisted of the heavy pollution regions, SCRB and ZRB, and another composed of Cd pollution. These results indicate that heavy metal contamination, especially Cd, should be taken into account during development of management strategies to protect the aquatic environment in the limnetic ecosystems of eastern China, especially in the two aforementioned basins. PMID:25412580

Heavy metal contamination in the surface sediments of representative limnetic ecosystems in eastern China.

PubMed

Tang, Wenzhong; Shan, Baoqing; Zhang, Hong; Zhang, Wenqiang; Zhao, Yu; Ding, Yuekui; Rong, Nan; Zhu, Xiaolei

2014-11-21

A comprehensive analysis of heavy metal pollution was conducted in the representative limnetic ecosystems of eastern China, which are subject to rapid economic development and population growth. The results demonstrated that the average contents with standard deviations of Cd, Cr, Cu, Ni, Pb and Zn in the surface sediments were 0.925 ± 0.936, 142 ± 46.8, 54.7 ± 29.1, 60.5 ± 21.6, 61.9 ± 36.0 and 192 ± 120 mg/kg dry wt., respectively, and that higher values were mainly observed in the southern portion of the study area, especially in the basins of Southeast Coastal Rivers (SCRB) and the Zhu River (ZRB). The six heavy metals in the surface sediments all had anthropogenic origins. In addition, the limnetic ecosystems, especially in the southern portion of the study area were found to be polluted by heavy metals, especially Cd. Overall, two hotspots of heavy metal pollution in the limnetic ecosystems of eastern China were found, one that consisted of the heavy pollution regions, SCRB and ZRB, and another composed of Cd pollution. These results indicate that heavy metal contamination, especially Cd, should be taken into account during development of management strategies to protect the aquatic environment in the limnetic ecosystems of eastern China, especially in the two aforementioned basins.

Phytoextraction of heavy metals from municipal sewage sludge by Rosa multiflora and Sida hermaphrodita.

PubMed

Antonkiewicz, Jacek; Kołodziej, Barbara; Bielińska, Elżbieta Jolanta

2017-04-03

The aim of the study was to evaluate the efficacy of the multiflora rose var. "Jatar" (Rosa multiflora Thunb. ex Murray) and the Virginia fanpetals (Sida hermaphrodita Rusby) to phytoextract heavy metals from municipal sewage sludge. The 6-year field experiment involved four levels of fertilization with sewage sludge at doses of 0, 10, 20, 40, and 60 Mg DM (Dry Mass) sludge ha -1 . The increasing doses of sewage sludge were found to significantly increase the yield of multiflora rose and Virginia fanpetals biomass. They also significantly increased the content of heavy metals in these plants. The highest uptake of heavy metals by the multiflora rose and Virginia fanpetals crops was recorded at the fertilization dose of 60 Mg DM ⋅ ha -1 . Our investigations show that the Virginia fanpetals was more efficient in the phytoextraction of Cr, Ni, Cu, Zn, and Cd from the sewage sludge than the multiflora rose, due to the greater yields and higher heavy metal uptake by the former plant. In turn, the multiflora rose phytoextracted greater amounts of Pb from the sewage sludge. The analyses indicate that the Virginia fanpetals can be used for phytoremediation (phytoextraction) of heavy metals contained in sewage sludge.

Evaluation of Heavy Metal Removal from Wastewater in a Modified Packed Bed Biofilm Reactor

PubMed Central

Azizi, Shohreh; Kamika, Ilunga; Tekere, Memory

2016-01-01

For the effective application of a modified packed bed biofilm reactor (PBBR) in wastewater industrial practice, it is essential to distinguish the tolerance of the system for heavy metals removal. The industrial contamination of wastewater from various sources (e.g. Zn, Cu, Cd and Ni) was studied to assess the impacts on a PBBR. This biological system was examined by evaluating the tolerance of different strengths of composite heavy metals at the optimum hydraulic retention time (HRT) of 2 hours. The heavy metal content of the wastewater outlet stream was then compared to the source material. Different biomass concentrations in the reactor were assessed. The results show that the system can efficiently treat 20 (mg/l) concentrations of combined heavy metals at an optimum HRT condition (2 hours), while above this strength there should be a substantially negative impact on treatment efficiency. Average organic reduction, in terms of the chemical oxygen demand (COD) of the system, is reduced above the tolerance limits for heavy metals as mentioned above. The PBBR biological system, in the presence of high surface area carrier media and a high microbial population to the tune of 10 000 (mg/l), is capable of removing the industrial contamination in wastewater. PMID:27186636

Geochemical and geo-statistical assessment of selected heavy metals in the surface sediments of the Gorgan Bay, Iran.

PubMed

Bastami, Kazem Darvish; Bagheri, Hossein; Haghparast, Sarah; Soltani, Farzaneh; Hamzehpoor, Ali; Bastami, Mousa Darvish

2012-12-01

We investigated heavy metal concentrations of zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb), their spatial distribution and enrichment factor index in surface sediments of the Gorgan Bay. Sediment Quality Guidelines were also applied to assess adverse biological effects of these metals. Heavy metals were determined by inductively coupled plasma-mass spectroscopy (ICP-MS). The results indicated mean concentrations (ppm) of heavy metals were (mean±S.D.) Pb: 11.5±4.88, Cu: 18±8.83, Zn: 42±22.15 and Cr: 32±15.19. Based on Enrichment index, the Gorgan Bay is a low-enriched to non-enriched bay. Heavy metal contents were lower than the standard limits of PEL, ERL, and ERM that reveal no threatening influence of the metals in the Bay. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Calculation of environmental dredging depth of heavy sediments in Zhushan Bay of Taihu Lake metal polluted].

PubMed

Jiang, Xia; Wang, Wen-Wen; Wang, Shu-Hang; Jin, Xiang-Can

2012-04-01

Horizontal distribution of heavy metals in surface sediments of Zhushan Bay was investigated, and core sediment samples were collected in the representative area. Core sediments were divided into oxide layer (A), polluted layer (B), upper polluted transition layer(C1), lower polluted transition layer(C2) and normal mud layer(D) from top to bottom. The change of total contents of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb and contents of biological available Cr, Ni, Cu, Zn, As, Cd, Pb with depths were analyzed. Ecological risk assessment of heavy metals in sediments was done by potential ecological risk index method. At last, environmental dredging depth was calculated. The results shows that the contents of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb are 30.56-216.58, 24.07-59.95, 16.71-140.30, 84.31-193.43, 3.39-22.30, 0.37-1.59, 0.00-0.80 and 9.67-99.35 mg x kg(-1), respectively. The average concentrations of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb are 79.74, 37.74, 44.83, 122.39, 10.39, 0.77, 0.14 and 40.08 mg x kg(-1), respectively. Heavy metals in the surface sediments of Zhushan Bay mainly distribute in the west bank and the estuaries of Taige canal, Yincun Port, and Huanshan River,and Cd pollution is relatively serious. There is an accumulative effect of heavy metals in Zhushan Bay, and the contents of biological available metals decrease with depths. Ecological risk grades of Cd in layer A and B are high, and the comprehensive potential ecological risk grades of each layer are in middle or low. The environmental dredging layers are A and B, and the average dredging depth is 0.39 m.

Noninvasive Evaluation of Heavy Metal Uptake and Storage in Micoralgae Using a Fluorescence Resonance Energy Transfer-Based Heavy Metal Biosensor1[C][W][OPEN

PubMed Central

Rajamani, Sathish; Torres, Moacir; Falcao, Vanessa; Ewalt Gray, Jaime; Coury, Daniel A.; Colepicolo, Pio; Sayre, Richard

2014-01-01

We have developed a fluorescence resonance energy transfer (FRET)-based heavy metal biosensor for the quantification of bioavailable free heavy metals in the cytoplasm of the microalga Chlamydomonas reinhardtii. The biosensor is composed of an end-to-end fusion of cyan fluorescent protein (CFP), chicken metallothionein II (MT-II), and yellow fluorescent protein (YFP). In vitro measurements of YFP/CFP fluorescence emission ratios indicated that the addition of metals to the purified biosensor enhanced FRET between CFP and YFP, consistent with heavy metal-induced folding of MT-II. A maximum YFP/CFP FRET ratio of 2.8 was observed in the presence of saturating concentrations of heavy metals. The sensitivity of the biosensor was greatest for Hg2+ followed by Cd2+ ≈ Pb2+ > Zn2+ > Cu2+. The heavy metal biosensor was unresponsive to metals that do not bind to MT-II (Na+ and Mg2+). When expressed in C. reinhardtii, we observed a differential metal-dependent response to saturating external concentrations (1.6 mm) of heavy metals (Pb2+ > Cd2+) that was unlike that observed for the isolated biosensor (in vitro). Significantly, analysis of metal uptake kinetics indicated that equilibration of the cytoplasm with externally applied heavy metals occurred within seconds. Our results also indicated that algae have substantial buffering capacity for free heavy metals in their cytosol, even at high external metal concentrations. PMID:24368336

[Spatiotemporal variation characteristics of heavy metals pollution in the water, soil and sediments environment of the Lean River-Poyang Lake Wetland].

PubMed

Jian, Min-Fei; Li, Ling-Yu; Xu, Peng-Fei; Chen, Pu-Qing; Xiong, Jian-Qiu; Zhou, Xue-Ling

2014-05-01

Overlying water, sediments, surface soils in the typical wetland areas of Lean River and Poyang Lake which were rich in non-ferrous metal mineral resources on both sides of the river, were chosen for monitoring heavy metals including copper, lead and cadmium of base flow in average season, flood season, and dry season in 2012. Statistical analysis methods were coupled to characterize the spatiotemporal variation of heavy metals pollution and identify the main sources. The results indicated that the concentrations of copper were the highest in all samples of each sampling sites in the Lean River-Poyang Lake wetland. And the content values of copper, lead and cadmium in different samples of different sampling sites also showed that the content values of copper were higher than those of lead, and the content values of lead were also higher than those of cadmium. The results also showed that the heavy metals pollution of copper, lead and cadmium in flood season was the heaviest whereas the heavy metals pollution in dry season was comparatively light. The results of the contents of the three kinds of heavy metals elements in different sampling sites of the watersheds of lean River showed that the contents of copper in the samples from the upstream sampling sites of Lean River were higher than those of other samples from other sites. And the contents of lead in the samples from the downstream sampling sites of Lean River were higher than those of other samples from other sampling sites. The contents of cadmium in the samples from the midstream sampling sites of Lean River were higher than those of other samples from other sites. The first principal component representing copper pollution explained 36. 99% of the total variance of water quality. The second principal component concerning representing lead pollution explained 30. 12% of the total variance. The correlation analysis results showed that there were significant positive correlations among the contents of copper

Study of heavy metals transport by runoff and sediments from an abandoned mine: Alagoa, Portugal

NASA Astrophysics Data System (ADS)

Gerardo, R.; de Lima, J. L. M. P.; de Lima, M. I. P.

2009-04-01

Over time, several studies have been designed to understand heavy metals fate and its impact on the environment and on human health. However, only a few studies have focused on the transport of heavy metals in mining areas through the various hydrological processes such as runoff, infiltration, and subsurface flow. In particular, heavy rainfall events have a great impact on the dispersion of metals existing in the soil. This problem is often more serious in abandoned and inactive mining sites causing environmental problems. In Portugal, there are 175 identified abandoned mines that continuously threaten the environment through acid drainage waters that pollute the soil as well as surface and groundwater. An example is the abandoned mine of Alagoa, located near the village of Penacova (Centre of Portugal); in this site mining activities ceased about 30 years ago. The area is characterized by very steep slopes that are confining with a small stream; the mining excavation by-products were deposited on these slopes. We have selected this mine as a case study, aiming at understanding the transport mechanisms and dispersion of heavy metals and at contributing to the definition of the most appropriate mitigation measures for this area that is contaminated by heavy metals from the mine tailings. So far a total of 30 soil samples from 3 contaminated zones were collected and analysed for pH, texture and heavy metal content, using atomic absorption spectroscopy. Results indicate that the contents of Zn and Pb in the soil samples are in the range from 95-460 mg/kg and 67-239 mg/kg, respectively, which exceed the critical limit-values defined by the Portuguese legislation. These metals are dispersed downslope and downstream from the mine tailings by storm water. The next step of this work is to investigate the transport of heavy metals by runoff, by mobilization of sediments and by subsurface flow. Three spatial scales tests will be conducted: on the mine tailings, on the slope

Microwave-assisted pyrolysis of textile dyeing sludge, and migration and distribution of heavy metals.

PubMed

Zhang, Hedong; Gao, Zuopeng; Liu, Yang; Ran, Chunmei; Mao, Xiao; Kang, Qinhao; Ao, Wenya; Fu, Jie; Li, Jing; Liu, Guangqing; Dai, Jianjun

2018-05-01

This study investigated the pyrolysis characteristic of textile dyeing sludge (DS) using an auger pyrolyser under microwave irradiation at different pyrolysis temperature. The migration and distribution characteristic of heavy metals and their potential ecological risks were investigated using inductively coupled plasma mass spectrometry (ICP-MS) techniques. Temperature and additives (e.g. Ca-bentonite, kaolin and CaO) significantly affected product distribution and yields. Heavy metals showed different enrichment characteristics during pyrolysis and a great percentage of the heavy metals was retained in the sludge char (SC), depending on different temperatures and additives. CaO had a strong ability for retention of S, Pb and Ni. Ca-bentonite, kaolin and CaO had considerable ability to retain Cr at 650 ℃. Ca-bentonite and CaO had positive effects on Ni retention at 450 °C and 650 °C. As was enriched at 450 °C with addition of Ca-bentonite. Cu and Zn were enriched at 450 °C and 850 °C without additives and the corresponding residue ratios (RRs) were 88.68-100%, which indicated good stability of these heavy metals during microwave pyrolysis of DS. The heavy metal contents in SC were lower than those in the national standards (CJ/T 362-2011, China) and these heavy metals showed slight potential ecological risk to the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Heavy metal accumulation imparts structural differences in fragrant Rosa species irrigated with marginal quality water.

PubMed

Ahsan, Muhammad; Younis, Adnan; Jaskani, Muhammad Jafar; Tufail, Aasma; Riaz, Atif; Schwinghamer, Timothy; Tariq, Usman; Nawaz, Fahim

2018-09-15

Wastewater is an alternative to traditional sources of renewable irrigation water in agriculture, particularly in water-scarce regions. However, the possible risks due to heavy metals accumulation in plant tissues are often overlooked by producers. The present study aimed to identify heavy metals-induced structural modifications to roots of scented Rosa species that were irrigated with water of marginal quality. The chemical and mineral contents from the experimental irrigation canal water (control) and treated wastewater were below the limits recommended by the Pakistan Environmental Protection Agency (Pak-EPA) for medicinal plants. The experimentally untreated wastewater contained electrical conductivity (EC), chemical oxygen demand (COD), biological oxygen demand (BOD), and heavy metals (Co, Cu, Cd, Pb) that were above the recommended limits. The responses by wastewater-treated Rosa species (Rosa damascena, R. bourboniana, R. Gruss-an-Teplitz, and R. centifolia) were evaluated. The experimental data revealed that treated wastewater significantly increased the thickness of collenchyma (cortex and pith) and parenchyma tissues (vascular bundle, xylem, and phloem) of R. Gruss-an-Teplitz. Root dermal tissues (epidermis) of R. bourboniana also responded to treated wastewater. R. damascena and R. centifolia were the least affected species, under the experimental irrigation conditions. Collenchyma and dermal tissues were thicker in R. damascena and R. Gruss-an-Teplitz under untreated wastewater conditions. In parenchyma tissues, vascular bundles were thicker in R. damascena in untreated wastewater conditions, while the xylem and phloem of R. Gruss-an-Teplitz were thicker where treated wastewater was applied. In tissues other than the vascular bundle, the differences in anatomical metrics due to the experimental irrigation treatments were greater during the second year of the experiment than in the first year. The contents of metals other than chromium in the roots and

Effects of heavy metal pollution of highway origin on soil nematode guilds in North Shenyang, China.

PubMed

Han, Dechang; Zhang, Xiaoke; Tomar Vijay Vikram, Singh; Li, Qi; Wen, Dazhong; Liang, Wenju

2009-01-01

Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha (Shenyang-Harbin) Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu, Zn, and the nematode community structure were analyzed. The results showed that the contents of total and available Pb, Cu, Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway. The zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.

[Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

PubMed

Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

2013-03-01

The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

Crater-lake Santa Maria del Oro as a Pristine Reference for Persistent Organic Pollutants (POP' s) and Heavy Metals Content in Environmental Investigations in Western Mexico (Project Conacyt-Semarnat 2002-C01-0463, in Progress).

NASA Astrophysics Data System (ADS)

Zarate-Del Valle, P. F.; Gomez-Hermosillo, C. M.; Venegas-Garcia, D. J.

2007-12-01

Santa Maria del Oro Lake ( SMO) (21.37° N, 104.57° W; 750 m a.s.l.) is a quaternary crater-lake located at western Mexico in the natural border between two geological provinces: the plio-quaternary Trans-Mexican Volcanic Belt and the oligo-miocenic silicic volcanic province Sierra Madre Occidental. SMO, a tropical freshwater lake, is a warm-monomictic lake having a diameter of ca. 2 km and a mean depth at the depocenter of ca. 60 m, where three benthos cores were recovered. Contents of POP' s, total inorganic carbon (TIC), total organic carbon (TOC) and heavy metals were analyzed. Geochemistry and mineralogy also were studied in shallow sediments which corresponded to the decade of 50-60's, otherwise the beginning of industrial development of central Mexico; which is considered the possible source of emission of POP' s and heavy metals. Dioxin, furan, plaguicides and PCB' s contents were analyzed by a GC-MS applying USEPA methods. In the first 40 cm (n= 20) of the sedimentary column ( SC) the absence of POP' s was evidenced, applying a method detection limit ( MDL) of 5 μ g/ml for dioxin, furan and PCB' s. For plaguicides like chlordane and toxaphene the MDL was 0.5 μ g/ml and for plaguicides like DDT, aldrin, endrin, dieldrin, heptachlore and mirex the MDL was 5 μ g/ml. The MDL for HCB was 1 μ g/ml. The average (n= 30) for TIC, TOC and total carbon (TC) for the first 40 cm of the SC is as follows: TIC 2.4 %, TOC 3.7 % and TC 6.12 %. The average (n= 20) content (in ppm) of heavy metals for the first 20 cm of the SC is as follows: As 5.97, Cr 27.54, Cu 16.31, Ni 12.29, Pb 21.35 and Zn 82.46. These contents are roughly similar to the clarke of these metals in volcanic rocks. After the criteria of severe effect level ( SEL) of heavy metal in sediments, the content of these metals is below SEL levels. These results permit us to conclude that the sediments of SMO can be considered in unaffected state with respect to antropogenic contamination like POP' s and heavy

[GIS Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments of Shallow Lakes in Jiangsu Province].

PubMed

Li, Ying-jie; Zhang, Lie-yu; Wu, Yi-wen; Li, Cao-le; Yang, Tian-xue; Tang, Jun

2016-04-15

To understand pollution of heavy metals in surface sediments of shallow lakes, surface sediments samples of 11 lakes in Jiangsu province were collected to determine the content of six heavy metals including As, Cr, Cu, Pb, Zn and Ni. GIS was used to analyze the spatial distribution of heavy metals, and geological accumulation index (Igeo), modified contamination index (mCd) pollution load index (PLI) and potential ecological risk index (RI) were used to evaluate heavy metal contamination in the sediments. The results showed that: in the lakes' surface sediments, the average content of As, Cu, Zn, Cr, Pb, Ni in multiples of soil background of Jiangsu province were 1.74-3.85, 0.65-2.66, 0.48-3.56, 0.43-1.52, 0.02-1.49 and 0.12-1.42. According to the evaluation results of Igeo and RI, As, which had high degree of enrichment and great potential ecological risk, was the main pollutant, followed by Cu, and pollution of the rest of heavy metals was relatively light. Combining the results of several evaluation methods, in surface sediments of Sanjiu Lake, Gaoyou Lake and Shaobo Lake, these heavy metals had the most serious pollution, the maximum pollution loading and moderate potential ecological risk; in surface sediments of Gehu Lake, Baima Lake and Hongze Lake, some regions were polluted by certain metals, the overall trend of pollution was aggravating, the pollution loading was large, and the potential ecological risk reached moderate; in the other 5 lakes, the risk of sediments polluted by heavy metals, as well as the pollution loading, was small, and the overall was not polluted.

Monitoring heavy metal Cr in soil based on hyperspectral data using regression analysis

NASA Astrophysics Data System (ADS)

Zhang, Ningyu; Xu, Fuyun; Zhuang, Shidong; He, Changwei

2016-10-01

Heavy metal pollution in soils is one of the most critical problems in the global ecology and environment safety nowadays. Hyperspectral remote sensing and its application is capable of high speed, low cost, less risk and less damage, and provides a good method for detecting heavy metals in soil. This paper proposed a new idea of applying regression analysis of stepwise multiple regression between the spectral data and monitoring the amount of heavy metal Cr by sample points in soil for environmental protection. In the measurement, a FieldSpec HandHeld spectroradiometer is used to collect reflectance spectra of sample points over the wavelength range of 325-1075 nm. Then the spectral data measured by the spectroradiometer is preprocessed to reduced the influence of the external factors, and the preprocessed methods include first-order differential equation, second-order differential equation and continuum removal method. The algorithms of stepwise multiple regression are established accordingly, and the accuracy of each equation is tested. The results showed that the accuracy of first-order differential equation works best, which makes it feasible to predict the content of heavy metal Cr by using stepwise multiple regression.

Hydroponics reducing effluent's heavy metals discharge.

PubMed

Rababah, Abdellah; Al-Shuha, Ahmad

2009-01-01

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

Phytoremediation of heavy metals--concepts and applications.

PubMed

Ali, Hazrat; Khan, Ezzat; Sajad, Muhammad Anwar

2013-05-01

The mobilization of heavy metals by man through extraction from ores and processing for different applications has led to the release of these elements into the environment. Since heavy metals are nonbiodegradable, they accumulate in the environment and subsequently contaminate the food chain. This contamination poses a risk to environmental and human health. Some heavy metals are carcinogenic, mutagenic, teratogenic and endocrine disruptors while others cause neurological and behavioral changes especially in children. Thus remediation of heavy metal pollution deserves due attention. Different physical and chemical methods used for this purpose suffer from serious limitations like high cost, intensive labor, alteration of soil properties and disturbance of soil native microflora. In contrast, phytoremediation is a better solution to the problem. Phytoremediation is the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is a relatively recent technology and is perceived as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. Phytoremediation is an area of active current research. New efficient metal hyperaccumulators are being explored for applications in phytoremediation and phytomining. Molecular tools are being used to better understand the mechanisms of metal uptake, translocation, sequestration and tolerance in plants. This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of sediment characteristics on the heavy metal concentration and their ecological risk level of surface sediments of Vaigai river, Tamilnadu, India.

PubMed

Paramasivam, K; Ramasamy, V; Suresh, G

2015-02-25

The distributions of the metals (Al, Fe, Mg, Cd, Cr, Cu, Ni, Pb and Zn) were measured for the surface sediments of the Vaigai river, Tamilnadu, India. These values are compared with different standard values to assess the level of toxicity of the heavy metals in the sediments. Risk indices (CF, PLI and PER) are also calculated to understand the level of toxicity of the metals. Multivariate statistical analyses (Pearson's correlation analysis, cluster analysis and factor analysis) are carried out to know the inter-relationship between sediment characteristics and the heavy metals. From this analysis, it is confirmed that the contents of clay and organic matter play an important role to raise the level of heavy metal contents as well as PLI and PER (level of toxicity). Heavy metal concentrations of the samples (after removing silt and clay fractions from bulk samples) show decrease in their concentrations and risk indices compared to the level of bulk samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Contamination of Polish national parks with heavy metals.

PubMed

Staszewski, Tomasz; Łukasik, Włodzimierz; Kubiesa, Piotr

2012-07-01

The paper presents results of screening analysis of all Polish national parks (23) contamination with Cd, Cu, Pb and Zn on the basis of a three-level characteristic of heavy metal presence in Norway spruce stands: accumulation on the needle surface, concentration of heavy metals in spruce needles and concentration of bioavailable heavy metals in the soil. Based on the obtained results, the classification of forest ecosystem hazard in national parks with heavy metals was made using synthetic indicators. It was found out that Babiogórski, Magurski, Ojcowski and Gorczański National Parks, located in the southern part of the country, were the most polluted with heavy metals. It is probably due to a higher industrial activity in this part of Poland and the transboundary transport of air pollutants. A little lower level of pollution was observed in Kampinoski National Park located in the middle of the country. The concentration of heavy metals found in needles from national parks does not seem to be harmful for the health status of the trees. Statistically significant correlation between all parameters, which was found for cadmium--the most mobile of the analysed elements--shows that this metal can be proposed as a marker to reflect present effect of industrial emission on forests.

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