Phytoremediation of Cd,Ni, Pb and Zn by Salvinia minima

Most metals disperse easily in environments and can be bioconcentrated in tissues of many organisms causing risks to the health and stability of aquatic ecosystems even at low concentrations. The use of plants to phytoremediation has been evaluated to mitigate the environmental contamination by metals since they have large capacity to adsorb or accumulate these elements. In this study we evaluate Salvinia minima growth and its ability to accumulate metals. The plants were cultivated for about 60 days in different concentrations of Cd, Ni, Pb and Zn (tested alone) in controlled environmental conditions and availability of nutrients. The results indicated that S. minima was able to grow in low concentrations of selected metals (0.03 mg L^?1 Cd, 0.40 mg L^?1 Ni, 1.00 mg L^?1 Pb and 1.00 mg L^?1 Zn) and still able to adsorb or accumulate metals in their tissues when cultivated in higher concentrations of selected metals without necessarily grow. The maximum values of removal metal rates (mg m² day^?1) for each metal (Cd = 0.0045, Ni = 0.0595, Pb = 0.1423 e Zn = 0.4046) are listed. We concluded that S. minima may be used as an additional tool for metals removal from effluent.     

Distribution patterns of Cd,Cu, Mn,Pb and Zn in wood fly ash emitted from domestic boilers

Abstract

Wood fuels being a renewable source of primary energy have been considered environmentally friendly. However, wood combustion in domestic boilers is a source of air pollution. The lack of a dust collection device is the reason why flue gases emit a significant load of particulate pollutants into the air, including heavy metals. The aim of this research was to assess the environmental hazard caused by both emissions of heavy metals during wood combustion in domestic boilers and their chemical forms present in fly ash.

From the various wood fuels burnt in domestic boilers, the fly ash selected for this study came from the combustion of briquettes of softwood from non-polluted areas, and from burning hardwood fuel from trees exposed to pollutants from heavy traffic. The wood fuels satisfy the quality demands determined in the EN 14961 Solid Biofuels - Fuel quality assurances. However, the concentrations of Cd, Cu, Pb and Zn in the fly ash are considerably higher than the appropriate limit values determined for soil improvers. Sequential extraction shows that Cd and Zn are associated mainly with the water leaching and carbonate fractions, regarded as mobile and bioavailable, and pose the potentially greatest hazard to the environment and human health. Cu, Mn and Pb associated with less mobile fractions may not pose a direct air quality hazard but, due to their high concentrations, medium-term and long-term effects on soils and surface and subsurface waters should be considered.     

Effects of mine effluent on uptake of Co,Ni, Cu,As, Zn,Cd, Cr and Pb by aquatic macrophytes

Concentrations of Ni, Co, Cu, Pb, Zn, Cd, Cr and As were determined in aquatic sediments, water and macrophytes collected from a fluvial system, contaminated by mine effluents. Myriophyllum verticillatum collected in May below the trace element point source accumulated 169 µg/g of Ni, 860 µg/g of Co, 37 µg/g of Cu, 31 µg/g of Pb, 92 µg/g of Zn, 6.9 µg/g of Cr and 1,200 µg/g of As (concentrations in dry weight). The aquatic macrophytes Nymphaea odoratae and Pontederia cordata accumulated the investigated trace elements to a much lesser extent. The concentrations of trace elements in Myriophyllum verticillatum decreased from May to August. Correlations were found between the concentrations of total Ni, Co and Cu in the bottom sediment and in the submerged macrophytes. However, there was no correlation between the amounts of these trace elements extractable by 0.5 N HCl from the sediments and the concentrations in the macrophytes.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.     

Bioaccessibility of Cd,Cr, Cu,Mn, Ni,Pb, and Zn in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) along the southeastern Black Sea coast

The adverse effect of seafood consumption on human health is related to the bioaccessibility in contrast with the total heavy metal level in the tissues. In this study, bioaccessibility of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) edible soft tissues collected along the southern Black Sea coast were investigated using in vitro digestion model. Total Pb concentration in the tissues was found to be higher than the maximum permissible limits set by European Commission. The bioaccessibility of metals in the tissues was found to be decreased in the order: Ni (83.11%) > Cu (80.47%) > Zn (76.86%) > Cd (73.32%) > Mn (69.11%) > Pb (61.07%) > Cr (58.44%). While significant positive linear regression was observed between total and bioaccessible concentrations for Mn, Pb, and Ni, significant negative linear regression was found for Cd (p < .05). The hazard quotients (HQ) calculated using bioaccessible amount were detected lower than the limit (HQ <1), which may not pose a potential hazard to humans reported by US Environmental Protection Agency. In sum, mussel consumption from sampling sites may cause a potential risk concerning human health especially for Cd and Pb in case of increased portion sizes.     

Element content (Cu, Fe, Mn, Ni, Pb, and Zn) of the ruderal plant Verbascum olympicum Boiss. from East Mediterranean

In this study, heavy metal content (Cu, Fe, Mn, Ni, Pb, Zn) was determined in soils and different organs of Verbascum olympicum Boiss. This species is endemic to Uluda? and spreads on destroyed areas such as: roadsides, developed building areas, ski lift stations and sheep folds. Soils and different organs (roots, stems, leaves and flowers) of plant samples were analyzed using an atomic absorption spectrophotometer for determining the element content. Heavy metal contents in soils and different organs in this species were highly correlated (P < 0.05). However, the contribution of plant organs to the accumulation capacity varied according to the metal. These results suggest that this species may be useful as a bioindicator for heavy metals.     

CEHIXM Extraction of Pb,Cd, Zn,and Mn from High Permeable Soils

A new method CEHIXM for extracting hea vy metals from high permeable soils under coupled electric-hydraulic gradient was investigated. Spent foundry sand, containing high levels of Pb, Cd, Zn, and Mn, was used as the contaminated source. A suitable ion-exchange resin was used for trapping and recovering the metals from the aqueous medium. Control experiments were conducted using hydraulic gradient alone to assess the leachability of the contaminants. The experiments were repeated with 50?V across the soil sample and without hydraulic gradient to evaluate ion migration under electric gradient. A number of CEHIXM experiments involving both hydraulic and electric gradients were conducted at a constant DC voltage of 50?V and a constant flow velocity of 0.0178?cm/ sec. With hydraulic gradient only, 3 to 8% metals were extracted, whereas with electric gradient only the metal removal rate was 0 to 0.7%. When the electric and hydraulic gradients were coupled, as much as 93% of Pb, 97% of Cd, 98% of Zn, and 94% of Mn were extracted, after 100?h of the processing.     

Potential of Typha angustifolia for phytoremediation of heavy metals from aqueous solution of phenol and melanoidin

Typha angustifolia was evaluated for various heavy metals (Cu, Pb, Ni, Fe, Mn, and Zn) bioremediation potential from aqueous solution containing variable concentrations of phenol (100–800 mg l^?1) and melanoidin (2500–8500 Co–Pt) at 20, 40, and 60 days. The concentration of phenol (200–400 mg l^?1) along with melanoidin 2500 Co–Pt showed optimum for phytoremediation of tested heavy metals, while, higher concentrations of melanoidin (5600–8500 Co–Pt) showed toxic effect on T. angustifolia along with phenol. Phenol and melanoidin showed adverse effect on T. angustifolia of up to 20 days incubation, but this leads to induction of peroxidase and ascorbic acid activity to cope with adverse conditions. Subsequently, as pollutants were decreased along with plant growth, peroxidase and ascorbic acid also declined. However, with reduction of peroxidase, catalase level was increased. The Cu, Zn, and Ni were accumulated at maximum in all tested conditions. The TEM observations of T. angustifolia showed clotted deposition of metals and shrinkage of cell in root, breakdown of spongy and palisade parenchyma of leaves at higher concentration of phenol (100 mg l^?1) and melanoidin (5500 Co–Pt). Thus, this study concluded that T. angustifolia could be a potential phytoremediator for heavy metals from metal, melanoidin, and phenol containing industrial wastewater at optimized condition.     

Trace Metals (Cd,Co, Cr,Cu, Hg,Ni, Pb,and Zn) in Food Supplements of Marine Origin

We determined the concentrations of Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn in dietary supplements of marine origin. Four supplement categories were studied; algae, coral, krill, and shark cartilage. A direct mercury analyzer was used for Hg determinations while acid digestions and ICP-AES were used for Cr analysis and ICP-MS for the other trace metals. Algae are the supplements showing the highest concentrations of Pb, Cr, and Ni with respective means of 1.6 mg Pb/kg dry weight (d.w.), 3.2 Cr mg/kg d.w., and 8.0 mg Ni/kg d.w. Krill supplements have the highest levels of Cd, Cu, and Zn with 0.65 mg Cd/kg d.w., 63 mg Cu/kg d.w., and 50 mg Zn/kg d.w., respectively. Shark cartilage supplements show the highest levels of Hg and Co with mean concentrations of 160 μg Hg/kg d.w. and 73 ± 51 μg Co/kg d.w., respectively. No samples in our study exceeded the provisional tolerable daily intakes set by Health Canada, the joint committee of the World Health Organization/Food and Agricultural Organization, or the U.S. Environmental Protection Agency. Nevertheless, Ni and Pb in algae and Hg in shark cartilage may end up contributing to a very significant portion of the allowable daily intake—leaving little room for normal intake through food consumption and other exposure pathways.     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Trace elements (Al,Cd, Cr,Cu, Fe,Mn, Ni,Pb and Zn) in Mytilus galloprovincialis and Tapes decussatus from Faro and Ganzirri Lakes (Sicily,Italy): Flow cytometry applied for hemocytes analysis

BackgroundTrace elements present in sessile molluscs, are important because they are used in human consumption and it has significantly increased in recent years. While their filtering of the water can lead to their build-up of organic and inorganic materials that can be sampled and analyzed, this can also lead to bioaccumulation of harmful substances, such as essential and non-essential elements, that can harm the human health if in taken in high concentrations or for a long period of time.MethodsIn the present study, the trace metal content (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of two sessile crustaceans, 20 Mytilus galloprovincialis (mussel) and 20 Tapes decussatus (clam) in Faro and Ganzirri Lakes (Messina, Sicily, Italy) were analyzed. Haemolymph samples were taken on both molluscs in order to analyze the haemocyte population by flow cytometric analysis. Unpaired t-tests were used to determine significant differences for the essential and non-essential metallic elements concentrations in the lake waters and in the tissues of M. galloprovincialis and T. decussatus and for hemocyte populations R1 (halinocytes) and R2 (granulocytes).ResultsThe results suggested that that in Faro Lake, the tissue Al, Cr and Pb levels in M. galloprovincialis were higher than those for T. decussatus, in contrast to Mn, Fe, Ni, Cu, Zn and Cd, which were higher in T. decussatus. Unpaired t-tests showed that there were significantly higher proportions of halinocytes in M. galloprovincialis versus T. decussatus for both Faro Lake (41.8 % vs. 24.3 %; P < 0.001) and Ganzirri Lake (43.0 % vs. 22.4 %; P < 0.001). In contrast, while there were significantly higher proportions of granulocytes in Faro Lake (21.2 % vs. 9.1 %; P < 0.001), this difference was not seen for the granulocytes of M. galloprovincialis versus T. decussatus in Ganzirri Lake (9.6 % vs. 13.0 %).ConclusionThis study shows that M. galloprovincialis and T. decussatus can indeed bioaccumulate some of these metal, such that activation of the immune responses is specific to certain cell types. Future research must focus on the balance of trace elements in the consumption of these shellfish, and analyzes with more sophisticated tools can be used to diagnose the increased concentration of trace elements and the quantification of trace metals from shellfish to clams.     

Heavy metals (Cd, Pb, Zn, Ni, Cu and Cr(III)) removal from water in Malaysia: post treatment by high quality limestone

This paper presents the results of research on heavy metals removal from water by filtration using low cost coarse media which could be used as an alternative approach to remove heavy metals from water or selected wastewater. A series of batch studies were conducted using different particle media (particle size 2.36-4.75 mm) shaken with different heavy metal solutions at various pH values to see the removal behaviour for each metal. Each solution of cadmium (Cd), lead (Pb), zinc (Zn), nickel (Ni), copper (Cu) and chromium (Cr(III)) with a concentration of 2 mg/L was shaken with the media. At a final pH of 8.5, limestone has significantly removed more than 90% of most metals followed by 80% and 65% removals using crushed bricks and gravel, respectively. The removal by aeration and settlement methods without solid media was less than 30%. Results indicated that the removal of heavy metals was influenced by the media and not directly by the pH. Investigations on the removal behaviour of these metals indicated that rough solid media with the presence of carbonate were beneficial for the removal process. Adsorption and precipitation as metals oxide and probably as metals carbonate were among the two mechanisms that contributed to the removal of metals from solution.     

Investigation of Vetiver Grass Capability in Phytoremediation of Contaminated Soils with Heavy Metals (Pb,Cd, Mn,and Ni)

ABSTRACT

Soil contamination with heavy metals has become a worldwide concern. A sustainable technology to mitigate heavy metal contamination is extremely important. Phytoremediation is a cost-effective method, environmentally friendly, and esthetically pleasing. The aim of this study was to investigate the potential of Vetiver phytoremediation of soils contaminated with heavy metals. This research was conducted as a factorial design with four different heavy metals (lead, cadmium, manganese, and nickel) with three varying levels and also three replications for each treatment. Statistical analysis of data was performed using SPSS19 software and analysis of variance, Duncan and Pearson correlation tests. The results showed that, the highest uptake rate was related to lead metal with 282.45 mg/kg of dry soil and 83.4% uptake percentage. Then, the mean and percentage of adsorption for cadmium, nickel and manganese were 248.3 mg/kg (53.2%), 69.4 mg/kg (65.5%), and 63.29 mg/kg (61%), respectively. Lead was found to be the main component of uptake by Vetiver plant. It was found that the roots of the plant have absorbed more heavy metals than the shoots. And at the roots in total 1089.05 and on average 363.01 mg/kg and at the shoots 901.19 and on average 300.39 mg/kg, the metals used were adsorbed on three levels and four treatments. The results of analysis of variance, Duncan test and Pearson correlation showed that the effect of applied treatments on lead uptake in roots and shoots increased significantly (P ≤ 0.05) with increasing levels of treatments. The biological concentration factor was more than one, and the transfer factor was close to one. Therefore, it can be used as a phytostablization plant. The results showed that Vetiver can be considered as a refining plant due to its vegetative characteristics, cost-effectiveness and high adaptation to environmental conditions.     

Fluxes and budgets of Cd, Zn, Cu, Cr and Ni in a remote forested catchment in Germany

The input of heavy metals by atmospheric deposition to forested watersheds substantially decreased during the last decades in many areas. The goal of our study was to identify the present sinks and sources of metals and factors influencing metal mobility at the catchment and soil profile scale. We determined concentrations and fluxes of Cd, Zn, Cu, Cr and Ni in precipitation, litterfall, soil solutions (Oi, Oe, Oa horizon percolates, 20 and 90?cm soil depth) and runoff in a forest ecosystem in NE-Bavaria, Germany for 1?year. The metal concentrations in solutions were mostly <10???g?l^?1 beside Zn (<1200???g?l^?1). The present total deposition was estimated at 1.0, 560, 30, 1.2 and 10.4?g?ha^?1?year^?1 for Cd, Zn, Cu, Cr and Ni, respectively. The mass balance (total deposition minus runoff) at the catchment scale indicated actual retention of Zn, Cu and Ni, but an almost balanced budget for Cr and Cd. Considering the soil profile scale, the Oi horizon still acted as a sink, whereas the Oe and Oa horizons were presently sources for all metals. The solid?Csolution partitioning coefficients indicated higher mobility of Cd and Zn than of Cu, Cr and Ni in forest soils. In the mineral soil horizons, K_d values derived from field measurements were substantially larger than those predicted with empirical regression equations from Sauv?? et al. (Environ Sci Technol 34:1125?C1131, 2000; Environ Sci Technol 37:5191?C5196, 2003). The mineral soil acted as a sink for all metals beside Cd. Dissolved organic C and pH influenced the metal mobility, as indicated by significant correlations to metal concentrations in Oa percolates and runoff. The solid?Csolution partitioning coefficients indicated higher mobility of Cd and Zn than of Cu, Cr and Ni in forest soils. Overall, the decreased deposition rates have obviously induced a source function of the Oe and Oa horizon for metals. Consequently, mobilization of metals from forest floor during heavy rain events and near surface flow conditions may lead to elevated concentrations in runoff.     

Serum levels of Cd, Pb, Cu and Zn in cigarette smokers

In order to show the accumulation of Cd, Pb, Cu and Zn in smokers, levels of these metals in serum were determined in 108 subjects: 32 non-smokers, 37 average cigarette smokers and 39 heavy cigarette smokers. The analysis was carried out by potentiometric stripping analysis (PSA) with the Tecator "Striptec System". Backward oxidation time of the amalgamated metals, by means of electrolysis, in a thin "film" of mercury in an electrode, gives their concentration measure. Our data showed an increase in average values of Cd and Pb in the serum of heavy smokers compared with average and non-smokers. Instead, as regards Cu and Zn, no differences were found in the two groups of smokers compared with the non-smokers used as controls. Results obtained of the Cd and Pb levels in serum are compatible with the presence of these metals in cigarette tobacco and inhaling them could contribute to disease connected with their accumulation in the human organism. For these subjects the increase in Cd values is of particular importance as it could predispose pulmonary emphysema.     

Effects of Amendments on Growth and Uptake of Cd and Zn by Wetland Plants,Typha angustifolia and Colocasia esculenta from Contaminated Sediments

A pot study was conducted to compare the effects of amendments (CaHPO₄ and cow manure) on growth and uptake of Cd and Zn from contaminated sediments by two wetland plant species, Typha angustifolia and Colocasia esculenta. Contaminated sediments (Cd 33.2 mg kg^–1 and Zn 363 mg kg^–1) were collected from Mae Tao basin, Mae Sot district, Tak province, Thailand. The experiment consisted of 4 treatments: control (uncontaminated sediment), Cd/Zn, Cd/Zn + 5% CaHPO₄, and Cd/Zn + 10% cow manure. Plants were grown for 3 months in the greenhouse. The addition of CaHPO₄ resulted in the highest relative growth rate (RGR) and highest Cd accumulation in both T. angustifolia and C. esculenta while the lowest RGR was found in C. esculenta grown in the cow manure treatment. Both plant species had higher concentrations of metals (Cd, Zn) in their belowground parts. None of the amendments affected Zn accumulation. C. esculenta exhibited the highest uptake of both Cd and Zn. The results clearly demonstrated the phytoremediation potential of C. esculenta and the enhancement of this potential by CaHPO₄ amendment.     

Geochemical controls for Al, Fe, Mn, Cd, Cu, Pb, and Zn during experimental acidification and recovery of Little Rock Lake, WI, USA

Concentrations of Al, Fe, Mn, Cd, Cu, Pb, and Zn were measured in thereference and treatment basins of Little Rock Lake (Vilas County, Wisconsin), alow-alkalinity, seepage system (pH 6.1, alkalinity25eq/L) during six years of a whole-basinacidificationand the first four years of the lake's recovery. The treatment basin wasacidified with H₂SO₄ in three two-year steps to pH5.6, 5.1, and 4.7. By the end of year 4 of recovery, treatmentbasin pH increased to 5.3 as a result of internal alkalinity generation.During acidification, dissolved Mn and Fe (0.4mpore-size filters) increased at pH 5.6; dissolved Al, Cd, and Zn becameelevated at pH 5.1; and dissolved Pb at pH 4.7. Dissolved Cu remainedsimilar in both basins to pH 4.7. Al, Fe and Mn levels declinedsignificantly during the recovery period, approaching values at pH 5.3intermediate between the concentrations at pH 5.6 and 5.1 during acidification.Dissolved Al and Fe in the reference basin were near the equilibrium levels forsolubility of gibbsite (Al(OH)₃) and amorphousFe(OH)₃(s).The acidified basin was undersaturated relative to gibbsite, and dissolved Alwas limited by pH disequilibrium between the water column and sediments andpossibly by Al-DOC precipitation. Dissolved Fe apparently was controlled bysolubility of amorphous Fe(OH)₃(s) and Fe-DOC precipitation.Dissolved Mn levels in both basins were consistent with manganite[-MnOOH(s)] solubility. Elevated levels of Cd, Pb, and Zn in thetreatment basin during acidification probably resulted from less efficientscavenging of atmospherically-deposited Cd, Pb, and Zn by settling particles.     

Litter accumulation in woodlands contaminated by Pb,Zn, Cd and Cu

Summary Close to a primary lead-zinc-cadmium smelter the standing crop of litter in woodlands was found to be elevated relative to more distant sites. The total litter accumulation is similar to that from contaminated sites reported by other authors but in this case the concentrations of heavy metals are considerably lower than those reported for other sites. Evidence is provided to support the hypothesis that within the woodlands studied, litter accumulation is not closely pH dependent, but is clearly related to both cadmium and zinc concentrations in litter. Litter accumulation occurs in certain particle size ranges and fractionation shows that the weight of accumulated litter in these size ranges is highly correlated to cadmium concentrations. These results are discussed in relation to the reported possible long term effects of metal contamination on decomposition processes and the possibility of adaptation to these adverse effects.     

Kinetic sorption modelling of Cu, Ni, Zn, Pb and Cr ions to pine bark and blast furnace slag by using batch experiments

Storm water and landfill leachate can both contain significant amounts of toxic metals such as Zn, Cu, Pb, Cr and Ni. Pine bark and blast furnace slag are both residual waste products that have shown a large potential for metal removal from contaminated water. There are however many variables that must be optimized in order to achieve efficient metal retention. One of these variables is the time of which the solution is in contact with each unit of filter material. Metal sorption was studied in two laboratory experiments to improve the knowledge of the effects of contact time. The results showed that pine bark was generally more efficient than blast furnace slag when the metal concentrations were relatively small, whereas blast furnace slag sorbed most metals to a larger extent at increased metal loads. In addition, sorption to blast furnace slag was found to be faster than metal binding to pine bark. A pseudo-second-order kinetic model was able to describe the data well within 1000 s of reaction time.     

Soil chemical properties affect the concentration of elements (N,P, K,Ca, Mg,As, Cd,Cr, Cu,Fe, Mn,Ni, Pb,and Zn) and their distribution between organs of Rumex obtusifolius

Background and aims

The ionome (elemental composition) of grassland species has rarely been studied at the level of individual organs and little is known about effects of soil chemical properties on the ionome. Using the model oxalate plant Rumex obtusifolius, we asked how its biomass production and the distribution of elements between its organs is affected by soil chemical properties.

Methods

We established a pot experiment with R. obtusifolius planted in acidic non-contaminated control and in slightly acidic and alkaline soils anthropogenically contaminated by the risk elements As, Cd, Pb, and Zn. Both contaminated soils were untreated and treated by lime and superphosphate. We determined biomass production and the concentrations of elements in its organs.

Results

Biomass production was negatively related to the mobility of micro- and risk elements. Restricted transport of micro- and risk elements from belowground organs into leaves was recorded in untreated contaminated soils. In both lime-treated soils and in superphosphate-treated alkaline soil, elevated transport of micro- and risk elements from belowground organs into leaves was recorded in comparison to untreated contaminated soils. The lowest concentrations of micro- and risk elements were recorded in stems and seeds, followed by belowground organs and leaves.

Conclusions

R. obtusifolius is an As-, Cd-, Pb-, and Zn-excluder and is sensitive to high availability of micro- and risk elements in the soil. Soil chemical properties affect the distribution of essential elements within the plant greatly.