High Translocation Factor Values Research Articles

High phytoremediation and translocation potential of an invasive weed species (Amaranthus retroflexus) in Europe in metal-contaminated areas

We demonstrated the metal accumulation potential of Amaranthus retorflexus, a European weed species, both in moderately and strongly metal-contaminated sites. Metal accumulation in roots, stems, and leaves were studied. We also calculated the bioaccumulation factor (BAF), and translocation factor (TF) values to quantify the metal accumulation, and translocation between plant organs. Our findings indicated that metal accumulation correlated with metal concentration; that is plant organs accumulated higher concentration of metals in the contaminated area than in the control one. We found that the concentrations of Ba, Mn, Sr and Zn were the highest in leaves, and Al, Cr, Cu, Fe and Pb in roots. High BAF value was found for Sr in all studied areas, indicating this metal’s high accumulation potential of Amaranthus retorflexus. High TF values were found for Al, Ba, Cu, Fe, Mn, Sr and Zn; these metals were successfully transported to aboveground plant organs. We demonstrated that A. retroflexus, a fast-growing, rapidly spreading weed in Europe, was especially useful for heavy metal phytoremediation and phytoextraction.

Phytoremediation Potential of Native Hyperaccumulator Plants Growing on Heavy Metal-Contaminated Soil of Khatunabad Copper Smelter and Refinery, Iran

The characterization of prospective plants is one of the critical issues in the efficiency and success of the phytoremediation process. Due to adaption and tolerance to different environmental stresses, native plant species have priority in this method. This study examined fifty plants of five species, namely Launaea acanthodes, Artemisia sp., Cousinia congesta, Peganum harmala, and Stipa sp., growing near a smelter and refinery in Iran to identify potential species for phytoextraction and phytostabilization. Therefore, Pb, Ni, Mn, Mo, S, and Cu concentrations in sampled plants and soils were analyzed. Three different pollution indices, namely metal accumulation index (MAI), translocation factor (TF), and bioconcentration factor (BCF) were used for evaluating the metal concentrations in roots and shoots of each plant species. The results indicated that Artemisia sp., with values of 3.21, 1.09, and 1.14 for MAI, BCF, and TF, respectively, is appropriate for phytoextraction in the study area. Plants such as Launaea acanthodes and Cousinia congesta with high BCF and low TF values showed the potential for phytostabilization. Investigating the indices for different elements demonstrated that Launaea acanthodes had a BCF value greater than 1 and a TF value less than 1; therefore, this plant could be used in the phytoremediation of arsenic through the phytostabilization technique. Furthermore, copper has very low bioavailability in these plant species. In addition, these native plant species were highly capable of accumulating sulfur from the soil because the BCF and TF indices for all inspected species were higher than 1; for Launaea acanthodes, the relevant TF value was about 10. The proposed native plant could be applied in practical applications of phytoremediation for soil remediation of contaminated sites around the metal factories and mines in southeastern Iran.

Phytoremediation of Cadmium-Contaminated Soils: A Review of New Cadmium Hyperaccumulators and Factors Affecting their Efficiency

A promising solution for the remediation of cadmium (Cd) contaminated soil involves the use of Cd hyperaccumulators to reduce levels of soil Cd. The suitability of various plant species to act as cadmium (Cd) hyperaccumulators was reviewed by considering bioconcentration factor (BCF), translocation factor (TF) and Cd concentration in shoots relative to soil parameters such as pH and organic matter content, and planting and growing parameters. High BCF and TF values (max 81 and 13.7 respectively) were observed in soils with low soil Cd concentration, soil organic matter (SOM) content (< 2%) and low soil pH, with biannual harvesting possible for some species. Certain species such as Youngia erythrocarpa and Gnaphalium affine were efficient as hyperaccumulators in soil with > 40% SOM content.

Phytoremediation Potential of Selected Ornamental Woody Species to Heavy Metal Accumulation in Response to Long-Term Irrigation with Treated Wastewater

Arid and semiarid environments of Mediterranean countries suffer from scarcity of water resources, which limits their agriculture productivity. Using treated wastewater (TWW) is considered an alternative strategy for irrigation purposes in such areas. However, TWW contains substantial levels of heavy metals (HMs) and contaminants that pollute the environment and soil. The aim of this study is to evaluate the phytoremediation potential of six selected woody tree species under long-term irrigation with TWW. The concentration, bioaccumulation factor (BFC), translocation factor (TF), and comprehensive bioconcentration index (CBCI) of HMs were measured in the various parts (roots, bark, and leaves) of the studied tree species. The results show a general pattern of mineral accumulation in the roots and low translocation to the areal parts of various species. Cupressus sempervirens, which is a native species in Mediterranean environments, had higher TF values for Fe, Mn, Cu, Cr, Cd, and Pb metals in its areal parts compared to other tree species. The study shows that Ficus nitida has the potential to be a hyperaccumulator for Cd in its bark, with a TF value that exceeds 12. Deciduous trees species (Populus nigra and Robinia pseudoacacia) were found to have high TF values for Ni and Cd toward their areal parts, whereas a higher TF for Cr (1.21) was only found in P. nigra bark. Cupressus sempervirens had, significantly, the highest bark and leaf CBCI values (0.83 and 0.82, respectively), whereas Ficus nitida had the second-highest values in the bark and leaves (0.56 and 0.51, respectively). Therefore, Cupressus sempervirens and Ficus nitida are considered good hyperaccumulators for various HMs, and can be used for phytoremediation activities in polluted areas.

Assessment of the phytoremediation capabilities of bracken fern (Pteridium aquilinum) for the remediation of heavy metals (Pb, Ni and Cd) contaminated water

This study was carried out to investigate the potential uptake of heavy metals (Pb, Ni, and Cd) by Pteridium aquilinum plant from aqueous solutions. The whole plant strands were cultured in 36 experimental pots containing 5, 10 and 15 (mg/L) of Pb2+, Ni2+ and Cd2+ aqueous solutions. The plants were harvested after 24, 48, 72 and 96 hours of exposure and segmented into leaves, stem and root, respectively. The heavy metals content in the plant parts were analyzed using Atomic Absorption Spectrophotometer version VGP 210. The highest actual accumulations for Pb, Ni and Cd were recorded in the root at 15 mg/L of the aqueous solution after 96 hours of exposure with mean values of 4.29±0.04, 4.06±0.01 and 0.65±0.00 mg/kg, respectively. The highest total actual accumulations recorded in the plant were 9.19±0.14, 10.80±0.03, and 1.23±0.04 mg/kg for Pb, Ni and Cd, respectively. The accumulation of the heavy metals in the plant parts was in this order; root > stem > leaves. The results reveal that, the accumulation of heavy metals in the plant increases with increase in the concentration of the aqueous solutions and the duration of exposure to the aqueous solutions. The uptake of heavy metals by the plant is in this order; Ni > Pb > Cd. The translocation factor (TF) recorded for Pb, Ni and Cd in the plant were all greater than 1 (>1) except for Cd at exposure duration of 96 h in the 15 mg/L Cd2+ aqueous solutions, with the highest TF values of 2.500, 1.886 and 1.601, respectively. This indicates that more of the heavy metals were stored in the shoot. P. aquilinum is therefore described as a good accumulator plant, which could be used for phytoextraction of Pb, Ni and Cd in aqueous solutions of the metals. Key words: Phytoremediation, Pteridium aquilinum, heavy metals, contamination, translocation factor.

Uptake and allocation of selected metals by dominant vegetation in Poyang Lake wetland: From rhizosphere to plant tissues

Wetland plants have shown much potential for the removal of metals from soils by accumulating in plant tissues. Therefore, analysis of the metal accumulation and translocation capabilities of wetland plants is important for effective phytoremediation of heavily polluted wetlands. However, few studies have been conducted to analyze metal accumulation in metal-contaminated wetlands of Poyang Lake, China. The aim of this study was to investigate the absorption and transportation characteristics of metals (Cr, Ni, Cu, Zn, Cd, Pb) in five dominant plant species (i.e. Phragmites australis (Cav.) Trin. ex Steu, Triarrhena lutarioriparia L Liu, Carex cinerascens Kukenth., Artemisia selengensis Turcz. ex Bess., Phalaris arundinacea Linn), in three wetlands of Poyang Lake (China). The pollution assessment indicated that the studied wetlands were all polluted by metals with PLI (pollution loading index) >1 and Cd was the main pollutant presenting a high ecological risk. The metal concentrations in different plant tissues did not exceed either the toxic critical values or the hyperaccumulation critical values. Bioaccumulation factor (BAF) and translocation factor (TF) were used to clarify the accumulation and translocation characteristics of metals by wetland plants. Triarrhena and Artemisia showed significantly high BAF values for Cd (8.26 and 4.31, respectively); this indicated their suitability and potential for Cd phytostabilization. The significantly high TF values of Cd (5.29) and Pb (3.25) in Phragmites indicated its ability for Cd and Pb phytoextraction. The high BAF and TF also indicated the high potential of Triarrhena, Artemisia and Phragmites as hyperaccumulators. The correlation analysis and multiple statistical analysis indicated that interactive effects of soil properties on metal accumulation are more significant than any single soil property, and influence of soil properties may partly depend on plant species. This study provides valuable information for phytoremediation of metal contaminated wetlands with suitable plant species.

Remediation potential of early successional pioneer species Chenopodium album and Tripleurospermum inodorum

Remediation with plants is a technology used to decrease soil or water contamination. In this study we assessed the remediation potential of two weed species (Chenopodium album and Tripleurospermum inodorum) in a moderately metal-contaminated area. Metal concentrations were studied in roots, stems and leaves, in order to assess correlations in metal concentrations between those in soil and plants. Furthermore, we calculated bioaccumulation factor (BAF), bioconcentration factor (BCF) and translocation factor (TF) values to study the accumulation of metals from soil to plants and translocation within plants. We found correlation in metal concentrations between soil and plants. The metal accumulation potential was low in both species, indicating low BAF and BCF values. In contrast, high TF values were found for Mn, Ni, Sr, Zn, Ba, Fe, Cu and Pb in C. album, and for Fe, Mn, Ni, Zn and Sr in T. inodorum. Our results demonstrated that the potential of C. album and T. inodorum might be limited in phytoextraction processes; however, when accumulated, metals are successfully transported to aboveground plant organs. Thus, to achieve the efficient remediation of metal-contaminated soils, removal of the aboveground plant organs is recommended, by which soil disturbance can also be avoided.

Evaluation of the phytoremediation potential of native plants growing on a copper mine tailing in northern Chile

Mining operations in northern Chile are responsible for numerous mine tailings deposits, which may represent a risk to human health and the environment. This study evaluated the phytoremediation potential of three plant species (Prosopis tamarugo, Schinus molle and Atriplex nummularia) to remediate copper mine tailings in northern Chile. To improve the characteristics of the tailing, three treatments based on arbuscular mycorrhizal fungi and organic and inorganic amendments were applied. Plant roots and shoots and the associated tailings samples were collected and analyzed for total metal concentrations of Cu, Mn, Fe, Pb, Zn and Cd. Bioconcentration Factor (BCF) and Translocation Factor (TF) were estimated to evaluate the plant species potential for phytoremediation. The results show that A. nummularia presents high TF values on untreated tailings for Pb and Zn; on tailings treated with CaCO3/compost for Mn, Fe, Pb and Zn, and on tailings treated with CaCO3/compost/mycorrhizae only for Zn. P. tamarugo presents high TF values on the untreated tailings for Pb and Zn; and on tailings treated with CaCO3/compost for Mn. S. molle presents high TF values on untreated tailings for Cu, Mn, Pb and Zn; on the tailing treated with CaCO3/compost for Mn and Zn, and on the tailing treated with CaCO3/compost/mycorrhizae for Mn and Pb. High TF values show that the plants studied under the specific characteristics of the treated or untreated tailings, present the potential of being used for phytoextraction. Regarding the BCF, the experiments showed values lower than 1 for all the metals, except for Cd, which for A. nummularia developed in the amended tailing, presented potential characteristics of a hyperaccumulator. This metal even had in general BCF values higher than 1 and TF lower than 1, which shows the potential of the three evaluated species as phytostabilizers for Cd. Regarding the effect of the amendments, the untreated tailing presented lower removal efficiency than the tailings treated with CaCO3/compost (T1) and CaCO3/compost/mycorrhizae (T2). On the other hand, no significant difference was found between treatments T1 and T2.

Cobalt, chromium and nickel contents in soils and plants from a serpentinite quarry

Abstract. The former serpentinite quarry of Penas Albas (Moeche, Galicia, NW Spain) left behind a large amount of waste material scattered over the surrounding area, as well as tailing areas. In this area several soils were studied together with the vegetation growing spontaneously over them with the aim of identifying the bioavailability of heavy metals. The potential of spontaneous vegetation for phytoremediation and/or phytostabilization was evaluated. The pH of the soils ranges from neutral to basic, with very low organic matter and nitrogen contents. There are imbalances between exchangeable cations like potassium (K) and calcium (Ca), mainly due to high magnesium (Mg) content that can strongly limit plant production. Moreover, in all of the studied soils there are high levels of cobalt (Co), chromium (Cr) and nickel (Ni) (&gt;70, &gt;1300 and &gt;1300 mg kg−1, respectively). They exceed the intervention limits indicated by soil guideline values. Different soil extractions were performed in order to evaluate bioavailability. CaCl2 0.01 M is the most effective extraction reagent, although the reagent that best predicts plant availability is a mixture of low molecular weight organic acids. Festuca rubra, L. is the spontaneous plant growing in the soils that accumulates the highest amount of the metals, both in shoot and roots. Festuca also has the highest translocation factor values, although they are only &gt;1 for Cr. The bioconcentration factor is &gt;1 in all of the cases, except in the shoot of Juncus sp. for Co and Ni. The results indicate that Festuca is a phytostabilizer of Co and Ni and an accumulator of Cr, while Juncus sp. is suitable for phytostabilization.

MONITORING OF ENVIRONMENTAL POLLUTION IN A WOODY FOREST IRRIGATED WITH CONTAMINATED WASTEWATER SUBJECTED TO A PRIMARY TREATED

This study was aimed at monitoring the environmental pollution of aloamy sand soil cultivated with different tree woody species, i.e., Morus alba,Khaya senegalensis, Acacia saligna and Populus nigra and irrigated with treatedcontaminated wastewater through drip irrigation system. Some heavy metals, i.e,Cd, Co, Ni and Pb were determined in each of irrigation water, irrigated soil andgrown woody trees, whether the expected phytoremediators were able toaccumulate and translocate these heavy metals, from lower plant part tissues tothe upper ones, taking into consideration their concentrations in irrigation waterand irrigated soil. In order to achieve this target, two areas were selected inEgypt, i.e., a) Egyptian Chinese friendship woody forest of the previous four treespecies at Sadat City, Minufiyah Governorate, Egypt which irrigated with aprimary treated wastewater and b) Egyptian-Japanese woody forest at Wadi AlNatron, Behaira Governorate, which irrigated with natural underground water, asa control for Acacia saligna only.The obtained results showed an always seasonal difference as regardsdifferent studied heavy metal concentrations in irrigation water during 2010 thatwas noticeably higher than 2009. However, Ni and Pb concentrations inirrigation water of Sadat City area exceeded the permissible values of Egyptcontaminated water. Also, Ni concentration in the natural underground water ofWadi Al-Natron area exceeded the permissible limit values of fresh water. As forheavy metal concentrations in the soil, data revealed that Cd concentrations werefound in a low concentration at soil supporting Populus nigra vs a highconcentration in subsurface layer (20-40 cm) in the soil supporting Acaciasaligna. The highest concentration of Ni was occurred at subsurface layer (20-40cm) of soil supporting Acacia saligna and Khaya senegalensis. On the otherhand, soil Pb and Co concentrations were almost similar for the four tree species.Concerning the metal concentrations in tree species, there wereinsignificant differences for Cd concentrations in different tree stems, however,the different distribution pattern of Co concentrations in stem could becategorized in an ascending order of Populus > Morus > Khaya > Acacia. Coand Ni concentrations in leaves were also taken an ascending order of Morus >Khaya > Acacia > Populus. Pb concentrations in leaves were taken ascendingorder of Morus > Acacia > Khaya > Populus. All metals were successfullytransported from roots to stems for all the investigated tree species. In Morusalba metals showed translocation preferences of Pb > Ni > Co > Cd vs Cd > Pb> Ni > Co in Khaya, Cd > Ni > Co > Pb in Acacia and Pb > Co > Ni > Cd inPopulus. In addition, Morus alba exhibited Ni and Co highest translocationfactor values that were found only at the highest temperature degrees.Moreover, Ni and Co concentrations in plant were found to be affected bysoil pH, organic matter and irrigation water salinity these may be assistingnaturally to accelerate soil phytoremediation processes at warm climate underdesert regions. So, it could be recommended that using Morus alba and Populusnigra for metal removal from soil is only technically feasible in short time period if more metal can be made available by adding chemicals to soil that increasedtheir concentrations. It is essential in case of using Morus alba as aphytoremediator to discard any fruit or leaves, however, it is also recommendedto study the effect of accumulated metals in Morus leaves on silk warm as abiological indicator. The metal amounts extracted by plants can be put intoperspective by calculating a theoretically decrease in soil metal concentrationsfrom the known plant maximum metal concentrations in order to calculate theconcentration factor, i.e., CF = metal concentration in plant tissue/itsconcentration in the soil. This could be achieved according to the number ofplanted trees/fed. Also, it should be following up Ni concentration in the naturalunderground water at the Egyptian-Japanese forest to avoid Ni pollution.

Phytosequestration of Metals in Selected Plants Growing on a Contaminated Okhla Industrial Areas, Okhla, New Delhi, India

Contamination of metal ions in soil and water represents more pressing threats to resources as well as human health. The present research was carried out to screen the phytosequester plants growing in industrial waste- and wastewater-affected industrial areas of Okhla, New Delhi, India. Accumulation trend of metal Fe, Zn, Cu, Cr, Pb, Cd, Hg, and As from soil and wastewater by plants were collected for study. Among aquatic plants Hydrilla verticillata, Marsilea quadrifolia, and Ipomea aquatica were found to be highest metals accumulator, Eclipta alba and Sesbania cannabina among terrestrial plant were highest accumulator of metals. Among the algal spp. Spirulina platensis and Phormidium papyraceum were the most efficient in accumulating Cd and Hg. The maximum bioconcentration factor (BCF) was recorded in Hygroryza aristata for the metals (Hg, Cd) in M. quadrifolia (Cd, Cr), in E. alba (Cr, Cu), and in S. platensis (Hg, Pb). However, the translocation factor (TF) of metals was found more in M. quadrifolia followed by I. aquatica than other plants. Among all the plants, H. verticillata showed high TF and low BCF values for toxic metals (Pb, Cr) and was suitable for phytostabilization of these metals. Our study showed that native plant species growing on contaminated sites may have a potential of phytosequestration of these metals.

Potential of Sonchus Arvensis for the Phytoremediation of Lead-Contaminated Soil

Sonchus arvensis is one of the pioneer plant species that were found in the abandoned Bo Ngam Pb mine in Thailand. S. arvensis was collected from three sites. The highest Pb shoot concentration was 9317 mg kg−1 and the highest translocation factor (TF) and bioaccumulation factor (BF) values were 2.5 and 6.0, respectively. To investigate Pb uptake capacity of S. arvensis, a hydroponic experiment was performed for 15 d. S. arvensis exposed to 5 mg L−1 Pb solution had the highest Pb shoot accumulation (849 mg kg−1). In a pot study, S. arvensis was grown in Pb mine soils amended with organic and inorganic fertilizers for 2 mo. The addition of organic fertilizer to the soil increased plant dry biomass sharply. All treatments with ethylene-diamine-tetra-acetic acid (EDTA) had Pb accumulation in shoots greater than 1000 mg kg−1 and the highest Pb shoot accumulation was found in S. arvensis grown in soil amended with organic fertilizer and EDTA (1397 mg kg−1). In a field trial study, S. arvensis was grown at three sites in the mine area for 6 mo. S. arvensis could tolerate a total Pb of 100,000 mg kg−1 in the soil and accumulated Pb in the shoots up to 3664 mg kg−1 with high TF (2.19) and BF (2.38) values. These results suggest that S. arvensis is a good candidate for Pb phytoremediation.

Decontamination and/or revegetation of fly ash dykes through naturally growing plants

Present study is focused on the decontamination and/or revegetation of fly ash dykes through naturally growing plants, namely Calotropis procera, Cassia tora, Chenopodium album, Sida cardifolia, Blumea lacera. The results of sequential extraction study showed that maximum amount of metals (Na, K, Fe, Mn, Cr, Pb, Ni, Cd) were associated with residual and Fe–Mn fractions. Diethylenetriamine penta acetic acid (DTPA)–triethanolamine (TEA) extraction assessed the bioavailability of the metals. The total metal accumulation in tested plants was found in the order; C. album > S. cardifolia > C. tora > C. procera > B. lacera. The maximum bioconcentration factor (BCF) was recorded in S. cardifolia for the metals (Na, Fe, Zn, Cd), in C. procera for the metals (Mn, Cu, Ni, Cr) and in C. album for the metals (Co, Pb). However, the translocation factor (TF) of most of the metals was found more in S. cardifolia followed by C. album than other plants . Among all the plants, C. album have shown high BCF and low TF values for toxic metals (Pb, Cd) and suitable for phytostabilization of these metals. Principal component analysis was used to predict translocation behavior of the metals in different parts of the plants which was found similar for the metals (Cu, Zn, Mn, Cr). All examined plants are suitable for revegetation (naturally grows on fly ash dykes) and S. cardifolia and C. album may be used for decontamination purposes.