Total Amount Of Heavy Metals Research Articles

Salinity modifies heavy metals and arsenic absorption by the halophyte plant species Kosteletzkya pentacarpos and pollutant leaching from a polycontaminated substrate.

Phytomanagement of polycontaminated soils is challenging, especially in areas simultaneously affected by salinity. The wetland halophyte plant species Kosteletzkya pentacarpos was cultivated in a column device allowing leachate harvest, on a polycontaminated spiked soil containing Cd (6.5 mg kg−1 DW), As (75 mg kg−1 DW), Zn (200 mg kg−1 DW) and Pb (300 mg kg−1 DW) and irrigated with salt water (final soil electrical conductivity 5.0 ms cm−1). Salinity increased Cd bioavailability in the soil and Cd accumulation in the shoots while it had an opposite effect on As. Salinity did not modify Pb and Zn bioavailability and accumulation. Cultivating plants on the polluted soil drastically reduced the volume of leachate. In all cases, salinity reduced the total amounts of heavy metals removed by the leachate and significantly increased the proportion of Cd and Zn removed by the plants. Heavy metal contamination induced a decrease in shoot dry weight and an increase in malondialdehyde (an indicator of oxidative stress); both symptoms were alleviated by the additional presence of NaCl but this positive impact was not related to increase in protecting phytochelatins synthesis. It is concluded i) that bioavailability estimated by the 0.01M CaCl2 extraction procedure is not fully relevant from the heavy metal mobility, ii) that salinity decreased heavy metal percolation, especially in soils cultivated with K. pentacarpos and iii) that salinity improves plant tolerance to heavy metals in K. pentacarpos and that this species is a promising plant material for phytoremediation of polycontaminated soils.

Effect of Biochar on Available Heavy Metals During Sewage Sludge Composting and Land Application of Compost

The effects of biochar addition to compost on change characteristics and passivation effect of heavy metals (Cd, Pb, Cu, Zn, Ni) were investigated during the process of sludge composting with two different composts (group A:with biochar; group B:without biochar) and land application of compost. The results indicated that the total amount of heavy metals (except Ni) did not change significantly during the process of sludge composting and land application of compost. Additionally, biochar addition had little effect on the total amount of heavy metals. During the sludge composting process, five heavy metals (Cd, Pb, Cu, Zn, Ni) were passivated. Sludge composting with the addition of biochar can decrease the available contents of heavy metals, and the passivation effect of heavy metals was significant (P<0.05). The passivation rate of the five examined heavy metals (Cd, Pb, Cu, Zn, Ni)ranged from 16.39%-43.10%, and the passivation effect for Zn and Ni was more significant. However, the passivation effect was not significant in the sludge composting process without the addition of biochar (P>0.05). The concentrations of heavy metals in soil increased with the application of sewage sludge compost products. In the short term, biochar had a certain passivation effect on the available heavy metals in soils with sludge compost application, but the effect was not significant.

Distribution of Cu fraction in sediments using Suaeda heteroptera - Nereis succinea combination: A greenhouse study

A knowledge of the total amount of heavy metals is not enough to assess the environmental impact of polluted soils. Therefore, the determination of Cu fractions in sediment is important to evaluate its behavior in the environment and its mobilization capacity. The distribution of Cu (II) fractions in the sediment was studied in a laboratory simulation experiment. The results indicated that the distribution of Cu fractions was related to the concentration of Cu in sediments. In the Suaeda heteroptera group, the content of exchangeable and carbonate-bound were reducing, while the Fe-Mn oxide- and organic matter-bound were basically raising. In the Nereis succinea group, the content of Fe-Mn oxide- and organic matter-bound were from raising to reducing, and the residual was basically reducing with the increasing Cu concentrations. Generally speaking, the existence of N. succinea could enhance the uptake of Cu in the coastal sediment planted with S. heteroptera. When S. heteroptera and N. succinea in combination, effect of S. heteroptera and N. succinea on Cu fractions in sediments was significantly higher than the two working singly.

Assessment of the Speciation and Pollution of Heavy Metals in Paddy Soils from the Jiulong River Basin

Speciation characteristics of twelve heavy metals in 71 paddy soils from the Jiulong River Basin were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the modified BCR protocol. The risk assessment coding method (RAC), ratio of secondary phase and primary phase (RSP), and geoaccumulation index (Igeo) were applied to evaluate the pollution degree of heavy metals in the area. The results show that most of these elements are abundant in the paddy soils and the speciation characteristics of different heavy metals vary. The elements Cd and Mn mainly exist as acid soluble fractions in the soils, with a mean proportion of 46.2% and 35.2%, respectively; Fe and Pb mainly exist as reducible fractions in the soils, with a mean proportion of 64.5% and 41.5%, respectively; and V, Cr, Ni, As, Co, Sr, Zn, and Cu mainly exist as residual fractions in the soils, with a mean proportion of 79.6%, 78.4%, 73.1%, 67.7%, 51.9%, 49.7%, 45.3%, and 38.4%, respectively. The three pollution assessment methods focus on the acid-soluble phase, secondary phase, and total amount of heavy metals, respectively. All have their own application value and disadvantages of incompletion. The comprehensive analysis of these three pollution assessment methods helps to more accurately and comprehensively assess the pollution characteristics of the heavy metals. The results show that the paddy soils are moderately to severely polluted with Cd; the Mn and Sr pollution is mild to severe; the Zn, Pb, Cu, and Co pollution is mild to moderate; the As and Ni pollution is absent or moderate; and V, Fe, and Cr pollution is non-existent or mild.

Study on Purification Effect of Artificial Wetland on Micro-polluted River

The research on the purification effect of artificial wetland on micro-polluted river and the detection of aquatic plants showed that TP, TN, NH3-N and COD in river were significantly lower than those in untreated river, indicating that the artificial wetland has a good purification effect on these water quality indicators; Testing from different wetland types, it can be seen that the effect of removing TP, TN, NH3-N and other factors in the subsurface wetland is the best, and the artificial surface wetland is second, while the effect of removing COD factor it is close to that of artificial surface wetland. As for the effect of removing pollution factors in artificial wetlands in different seasons, it can be drawn frow the test that the removal rate of TP and TN in artificial wetlands in different seasons can be obtained: wet season &gt; normal season &gt; dry season; and the removal rate of NH3-N and COD is normal season &gt; dry season &gt; wet season. In addition to the TN factor, the water quality during the dry season and normal season is significantly better than that during the wet season. Based on the analysis of the total amount of heavy metals absorbed by three kinds of aquatic plants, it can be concluded that different plant has different effect of removing TN and TP.

Accumulation and transformation of heavy metals in surface sediments from the Yangtze River estuary to the East China Sea shelf

The concentration and speciation of heavy metals (Cu, Co, Ni, Zn, Cr, Pb and Cd) were studied in surface sediment from the Yangtze River(YR)to the East China Sea (ECS) shelf. The results showed that high contents of metals were found in the YR estuary (YRE) and in the nearshore muddy area, while lower concentrations were found in the YR channel and the ECS shelf. However, after standardization, the total content of most heavy metals from the YR showed little change or slightly increased during the transport process from the river to the estuary but decreased significantly outside the estuary, especially in the sediments of the ECS shelf. The residual fraction is the dominant fraction for all the metals, while the oxidizable and reducible fractions are the most important forms of the nonlithogenic fractions. The total amount of heavy metals from the YR to the continental shelf is mainly affected by the filtration of the estuary and the barrier impacts of the coastal current in the ECS. The environmental physicochemical conditions that vary significantly in the turbidity zone greatly influence the associated forms of metals. The metals in the acid-soluble fraction are mostly affected by the pH change in the sediment and the discharge of human activities, while the reducible fraction is significantly affected by the bottom water DO. The oxidizable fraction was affected by oxidation-reduction potential (ORP), primary productivity, as well as OM content. Therefore, with changes in the physicochemical conditions of the environment, the metals have undergone significant changes in their speciation from the YR to the ECS shelf. Various complex effects in the estuary area have not only a large filtration effect on the total amount of metals but also a major impact on the geochemical forms of the metals.

МОНИТОРИНГ ЗАГРЯЗНЕНИЯ СНЕЖНОГО ПОКРОВА г. ЧИТЫ ТЯЖЕЛЫМИ МЕТАЛЛАМИ

The forms of zinc, cadmium, lead and copper in the snow cover of Chita were determined. According to the numerical ecological-geochemical and sanitary-hygienic indicators, it was revealed that the city territory is characterized by an average and high level of pollution of snow cover. The main load of toxic ions accounts for the dust fraction of snow. By the dust load Pn the most unfavorable were Central (more than 12 t * km2 * day.) and East (more than 7 t·km2·day.) part of the city of Chita. This is probably due to the high anthropogenic load and the predominant direction of air masses. In addition, the relief and climatic factors that increase the retention of dust and toxic substances in the formation of dense smog are of great importance. The calculated average total load of the studied metals from the dust fraction (Zp = 76,295) corresponds to the low level of pollution, but there were also anomalies where there was a high level of this indicator. The share of water-soluble forms of pollutants does not exceed an average of 0.3% of the total amount of heavy metals. By the average value of the total load index (ZC) the share of water-soluble forms was 10.9%. However, the danger of this polluting factor is high, and when calculating the coefficient of contamination, it is necessary to dilute the melt water with clean water 84 times for fishing purposes and 15 times for economic and drinking use. For all forms of pollutants, the main sources of environmental revenues are thermal power and motor transport enterprises. A significant accumulation of toxic elements in the snow cover of Chita is associated with an unsuccessful location of the main industrial enterprises, the terrain of the territory and specific climatic conditions.

Comparision of Ecological Risk Assessment Based on the Total Amount and Speciation Distribution of Heavy Metals in Soil:A Case Study for Longyan City, Fujian Province

A total of 110 topsoil samples and 61 crop samples along the Lantian-Yangdong Villages were collected in Shizhong, Longyan City. The total amount and speciation of heavy metals(Pb, Cd, As) in soil and crops were determined. The characteristics of the absorption of heavy metals by specific crops in the study area were analyzed, and a new method of risk assessment based on the heavy metal speciation and its bioavailability was established by statistical analysis. This new method was used to evaluate the soil ecological risk and to compare it with the traditional method of potential ecological risk index (RI). The results indicated that the Lantian-Yangdong Villages were located in an area where Pb, Cd, and As mainly originate from the natural soil parent material with weak human disturbance. There was no significant Pb or As pollution in the whole region. Cd was the main pollutant with low pollution intensity. Four types of biological components except for the residual form followed the order of Cd(53.28%) > Pb(43.28%) > As(30.71%). Correlation and regression analyses of total metal concentrations, heavy metal speciation, and crop uptake in the study area showed that the correlations between the total amount of heavy metals and the ion exchange state, carbonate state, and other active forms were low; the results even showed nonlinear relationships between those variables.The ion exchange state had the greatest effect on the absorption of Pb, Cd, and As by coix seed and rice. From the perspective of bioavailability, the new method based on the heavy metal speciation was more accurate than the traditional method based on the total amount of heavy metals.

Distribution of heavy metals in maize and mudflat saline soil amended by sewage sludge

Sewage sludge has been considered as the economic choice for soil amendment. However, whether sewage sludge can effectively amend mudflat saline soil remains unclear. This paper was one of first studies to fill this knowledge gap by assessing the persistent effects of one-time application of sewage sludge on distribution of heavy metals in maize (Zea mays L.) grown in mudflat saline soil. On the premise of total amount of heavy metals from sewage sludge being in compliance with agricultural standard in China (GB/T 24600-2009), sewage sludge was used through one-time application, with the rates of 0, 30, 75, 150, and 300 t ha−1, to amend infertile mudflat soils. Ryegrass, Sesbania, and ryegrass were chosen as green manures for three consecutive seasons, successively planted and tilled. Maize was chosen as a test crop and sowed in 10th July 2013 and harvested 72 days after sowing. The results indicated that the sewage sludge amendment (SSA) increased uptake of cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in maize tissues, whereas it did not inhibit maize growth, and dry matter of maize plant tissues increased with increasing SSA rates. Total Cd, Cu, Pb, and Zn concentrations in mudflat soil increased with increasing SSA rates, but there were no significant changes in total Mn and Ni concentration in response to SSA. The highest Cd, Cu, Mn, Ni, and Pb concentrations were observed in roots of maize, and the root system acted as a barrier for metals, so metal uptake and translocation were lower in aerial parts of maize plant. The labile fraction of Cd, Cu, Mn, Ni, Zn, and immobile fraction of Pb in the sludge-amended soils increased with increasing SSA rates. The metal levels in grains were negligible in all the treatments and below the maximum permitted concentrations as specified in the national control standard in China (GB2715-2005). Sewage sludge can be applied with green manure for mudflat saline soil amendment, which provides an innovative solution for arable land resources and solid waste disposal.

The content of heavy metals in the leaves of Tilia cordata Mill. and in the soils of urban ecosystems of Cherkasy city

The growth of technogenic impact on urbo-landscapes is accompanied by man-made contamination of the environment. Among the most toxic and widespread pollutants of the urban ecosystems an important place belongs to heavy metals. The soil is the main source of accumulation of heavy metals and its uptake by the biota objects, including plants. Elevated concentrations of heavy metals in plant products, in turn, lead to intoxication of people and animals. Toxicity of heavy metals due to their biological activity and availability, resistance of their compounds in the environment, the possibility of small concentrations cause significant negative effects. For the city of Cherkasy the main polluters of the environment with heavy metals are the subsidiary of Cherkasy thermal power (accounting for 75% of the total amount of heavy metals emitted, and contribution of thermal power for emission of Pb, Cu and Zn reach 85%) and automobile transport. It should be noted that the city of Cherkasy (population 285.000 people) is an important economic center of Ukraine, with well-developed chemical and automobile industries. With atomic absorption spectroscopy the content of heavy metals (Cu, Zn, Pb and Cd) in the leaves of bio-indicator species Tilia cordata Mill. and soils from 24 localities of the city of Cherkassy was examined. The general content of the leaf biomass and soils from different localities of the degree of technogenic pollution of heavy metals are arranged in a sequence Zn &gt; Cu &gt; Pb &gt; Cd. In the city the content Pb and Cd in soils were below the MPK (maximum permissible concentration). Apparently, the content of copper and zinc soils, first of all, caused by pollution of chemical plants emissions, lead, due to industrial and transport factors and cadmium, of the distances to highways. The data obtained suggest that small-leaved linden (T. cordata Mill.) is as a representative species for bio-indication of heavy metals pollution in urban territories

Heavy metal compounds in a soil of technogenic zone as indicate of its ecological state

The emissions from the Novocherkassk power station comprise 1% of the total volume in the Russian Federation and up to 58% of the emissions in the Rostov oblast. The aim of this work was to assess the regularities of heavy metals accumulation and transformation in soils subjected to aerosol emissions from the power station on the basis of the fractional composition of their compounds. Studies have been conducted on the soils of monitoring plots distances from the power station (1.0–20.0 km) during 15 years. The monitoring plots located on fallow areas. Soil samples for the determination of soil properties and the contents of heavy metals compounds were taken from a depth of 0–20 cm. The soil cover in the region under study consisted of ordinary chernozems, meadow-chernozemic soils, and alluvial meadow soils. The total amount of heavy metals in soils was determined by X-ray fluorescence. Metals in soil extracts were determined by atomic absorption spectroscopy. The fractional composition of heavy metals was determined using combined fractionation. A combined approach for fractioning metal compounds in soils on the basis of and parallel extractions (1 N NH 4 Ac, pH 8; 1% EDTA in NH 4 Ac; and 1 N HCl) was used. Aerosol emissions from the power station are the major agents of technogenic impact on the soils under study in the Rostov oblast. The highest degree of contamination with metals (mg/kg: Ni - 64, Cd – 1.3, Cr - 145 and As – 12) was observed for soils located within a radius of 5 km from the power station along the predominant wind direction. It was marked the rise of metals mobility in the polluted soils and predominant participation of Cr and Ni organic-mineral complexes among their mobile species. The increasing of Cd mobility was provided predominantly by exchangeable forms and specifically sorbed by Fe-Mn (hydr)oxides. The environmental contamination hazard increases with the decreasing metal-buffering capacity of soils.

Distribution and phytoavailability of heavy metal chemical fractions in artificial soil on rock cut slopes alongside railways

Artificial soil is often sprayed onto cut slopes alongside railroad tracks to promote revegetation. This study evaluated the heavy metal content and the distribution of heavy metal chemical fractions in the soil, as well as the uptake of heavy metals by plants. The soil at four sites was determined to be considerably contaminated with Cd and Pb. The concentrations of Cd and Pb increased with the length of time the railway had been in use and decreased further away from the railway tracks. Pb primarily existed in reducible form but as residual fractions, whereas Cd was predominantly in exchangeable form. A correlation analysis indicated that pH, organic matter, and total phosphorus levels were important factors affecting the distribution of the heavy metal chemical fractions. The amounts of exchangeable Pb and Cd in the soil were highly correlated with their amounts in the plants sampled, indicating that the exchangeable fraction is a better indication of heavy metal phytoavailability than the total amount of heavy metals in the soil. Bioaccumulation and translocation factors indicated that Indigofera amblyantha had moderate tolerance and bioaccumulation capability for Pb, as did Leucaena leucocephala for Cd. These two plant species can serve as ideal slope remediation plants.

Evaluation of Heavy Metals and Polycyclic Aromatic Hydrocarbons in Honeys from Different Origins

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.

Heavy Metals in Atmospheric Particulate Matter: A Comprehensive Understanding Is Needed for Monitoring and Risk Mitigation

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Heavy Metal Contamination in Farm and Urban Soil in Mymensingh

A study was carried out to determine the status of heavy metals in farm and urban soils from intensively growing areas of Mymensingh. Sixty three soil samples were collected from 11 upazillas of Mymensingh. From these samples total amount of heavy metals like Pb, Cd, Ni, Cr, Fe and Mn were tested. The soils were also analyzed for texture, pH and organic matter content. The mean concentrations of Pb, Cd, Ni, Cr, Fe and Mn in farm soils were 19.64, 0.32, 39.80, 14.10, 1800.40, 135.66 ?g g-1, respectively and the mean concentrations of above metals in urban soils were 20.93, 0.37, 36.90, 28.85, 1810.08, 127.05 ?g g-1, respectively. The heavy metal concentrations in farm soils were within the limit allowed for maximum acceptable concentration for satisfactory crop production. Heavy metals in urban soils were also below the limit considered as contaminated soil. Most of the heavy metals in both farm and urban soils were negatively correlated with sand and positively correlated with silt. There was no significant correlation between heavy metal content and soil pH or organic matter in both farm and urban soils with very few exceptions. Most of the heavy metals did not show any significant correlation with each other expect Fe which showed significant correlation with Pb, Ni, Cr, Mn and Cd for both farm and urban soils.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14798 J. Environ. Sci. &amp; Natural Resources, 5(2): 81-84 2012

Characterization of the particle size fraction associated heavy metals in tropical arable soils from Hainan Island, China

Tropical arable soils were sampled from Hainan Island. The particle size fractions associated Cr, As, Cd and Pb were characterized and their leachability was analyzed as well. The pollution of heavy metals in the arable soils was not severe except Cr (204mgkg−1) in Haikou. The distribution of heavy metals increased with decrease of particle size. Although the smallest fractions (<53μm) occupied only 5.08–9.57%, they had the highest distribution factor (DF) of 3.50 for Cd, 2.11 for Pb, 1.73 for Cr and 1.09 for As, respectively. The contributions of micro-aggregates (<250μm) to the total amount of heavy metals was 41.9% for Cr, 44.6% for As, 61.6% for Cd and 48.6% for Pb, respectively, and the second mass loading came from the particles of 250–1000μm. The residues of Cr, Cd and Pb were correlated positively with the contents of organic carbon as well as Fe in fractions, while a large variation distribution of As was found in particles, indicating its high activity in soil microenvironment. The lowest leachability was found in the easily migratory micro-aggregates, which should be taken into account in the future environmental risk assessment and soil remediation.

Release of Heavy Metals from Concrete Made with Cement from Cement Kiln Co-Processing of Hazardous Wastes in Pavement Scenarios

Abstract Environmental safety assessments of products using cement from co-processing of hazardous wastes in cement kilns and formulation of criteria for pollution control of the cement products are necessary in Chinese environmental management departments. This article discusses the release of heavy metals from concrete using cement from the co-processing of hazardous wastes in cement kilns. The leaching test was based on typical applications of concrete in China. Total amount of heavy metals are much greater than leachability, and the ratio of total amount to leachability was dependent on the type of heavy metal. A good linear correlation between total amount and leachability of Cd was found (R2 is 0.994), but this was not the case for Cr, As, and Pb. pH influenced the release of heavy metals significantly, and the influences were related to the kinds of heavy metals. Diffusion control was the major release mechanism of Cr and Cd in concrete and the release curves fit very well the standard line with a ...

Heavy metals in outflows from a sewage treatment plant and in waters and sediments of ponds supplied with them

Abstract The examination of total amounts of heavy metals (Hg, Cd, Cu, Pb, Cr, Ni, Zn) was conducted in the outflow from a sewage treatment plant and in the waters and sediments of ponds supplied with them. As the water passed through the pond system, a decrease of heavy metal concentrations in the post-treatment sewage water supplying the ponds was observed. The highest concentrations of heavy metals were found in the outflow from the sewage treatment plant and lower concentrations were observed in the water of pond 1 (except for Zn), which was the direct receiver of post-treatment sewage, while the lowest values were noted in the final pond. The concentration of heavy metals in the sediments decreased in consecutive ponds. The highest concentrations were determined in the sediment of pond 1 that received the post-treatment sewage directly from the sewage treatment outflow, whereas the lowest values were estimated in the sediments of pond number 4, which was the final pond in the system.

The Role of Chloride Salts in Chemically Enhanced Phytoextraction of Heavy Metals From a Contaminated Agricultural Soil

Chemically enhanced phytoextraction of heavy metals has proved in several cases to be a perspective and costeffective method of soil remediation. The main drawback of this method continues to be the low mobility (and thus the bioavailability) of some heavy metals (e.g., lead [Pb]). The use of synthetic chelating agents, such as ethylenediaminetetraacetic acid (EDTA), significantly increased the mobility of heavy metals in soils and their translocation from the roots to the shoots of several plants (Blaylock et al., 1997; Huang et al., 1997). However, because of their high solubility and persistence in soils, chelates can possibly leach down the soil profile. Thus, they pose an important environmental risk for groundwater quality (Romkens et al., 2002). In addition, free EDTA and EDTAheavy metal complexes are potentially toxic to plants (Vassil et al., 1998). For these reasons, several alternatives to EDTA have been proposed. Among many, (S, S)-N, N’-ethylenediaminedisuccinic acid (EDDS), a biodegradable chelating agent, was introduced to minimize unwanted negative effects associated with the use of EDTA during phytoextraction experiments (Kos and Lestan, 2003). Xiong and Feng (2001) introduced chloride salts as another alternative for enhancing Pb accumulation in Brassica pekinensis. Highly soluble chloride salts dissociate in soil solution and thus provide (1) cations capable of exchanging the adsorbed heavy metals and (2) ligands needed to form watersoluble mobile complexes such as CdCl, CdCl3 , or CdCl4 . Other studies (Li et al., 1994; Smolders et al., 1998) also have proved the positive influence of chloride salts on heavy metal (especially Cd) accumulation in plants. The authors add that the use of chloride salts is preferred over the use of EDTA because of the lower costs and shorter dwell time of the formed soluble complexes in soils. Furthermore, the application of sodium chloride (NaCl) did not negatively influence plant biomass production to the extent that EDTA did (Xiong and Feng, 2001). However, many authors have focused on soils artificially spiked with a single metal in a form that does not correspond to natural conditions (e.g., Pb[NO3]2 or Cd[NO3]2) (e.g., Begonia et al., 2003, 2004; Hovsepyan and Greipsson 2005; Xiong and Feng, 2001). In addition, the application of mobilizing agents to soils contaminated with multiple metals can lead to a reduction in plant biomass yields and the total amount of heavy metals phytoextracted due to the toxicity of other metals present at high concentrations in the soil solution (Chen and Cutright, 2001). The main objectives of this study were (1) to determine the effect of different chloride salt (NH4Cl) concentrations on the mobility of cadmium (Cd), zinc (Zn), and Pb in a contaminated agricultural soil originating from the contaminated mining and smelting area of Přibram, Czech Republic, (2) to evaluate the phytoextraction efficiency of a hybrid poplar (Populus nigra · Populus maximoviczii) and maize (Zea mays) after the application of different NH4Cl concentrations, (3) and to compare the effectiveness of NH4Cl and EDTA in the phytoextraction process. M. Komarek (&) P. Tlustos J. Szakova Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture in Prague, Kamýcka 129, 165 21 Prague 6, Czech Republic e-mail: komarek@af.czu.cz

Study of the Transfer Coefficient of Cadmium and Lead in Ryegrass and Lettuce

The aim of study was to find the correlation between the concentration of the total amount of heavy metals of soils and that of plants because it shows which elements can be accumulated by different plants. The transfer coefficient is the metal concentration in plant tissues aboveground divided by the total metal concentration of soil. Pot experiments were conducted under greenhouse conditions. The total lead (Pb) content (about 21 mg · kg−1 soil) of soils was higher than the cadmium (Cd) content (about 0.21 mg · kg−1 soil). The Cd concentration of lettuce (averaging 0.93 mg · kg−1) was higher than that of ryegrass (averaging 0.20 mg · kg−1). The transfer coefficient of Cd was lower in ryegrass (averaging 0.95) than in lettuce (4.47). In this experiment, the concentration of Cd was almost five times higher in the four‐leaf lettuce than the Cd content of soil. The transfer coefficient of Pb was generally 0.064 in both plants.