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Translocation and accumulation of Cr, Hg, As, Pb, Cu and Ni by Amaranthus dubius (Amaranthaceae) from contaminated sites
Abstract
Phytoremediation is an emerging technology where specially selected and engineered metal-accumulating plants are used for bioremediation. This study was undertaken to evaluate the potential of Amaranthus dubius for phytoremediation of chromium (Cr), mercury (Hg), arsenic (As), lead (Pb), copper (Cu) and nickel (Ni). Locally gathered soil and plants of A. dubius were investigated for the metals from a regularly cultivated area, a landfill site and a waste water treatment site. Metals were extracted from the samples using microwave-digestion and analyzed using Inductively Coupled Plasma-Mass Spectroscopy. The mode of phytoremediation, effect of the metals on the plants, ability of the plant to extract metals from soil (Bioconcentration Factor) and the ability of the plants to move the metals to the aerial parts of the plants (Translocation Factor) were evaluated. The survey of the three sites showed that soils were heavily contaminated with Cr, Hg, Cu and Ni. These levels were far above acceptable standards set for soils and above the standards set for the Recommended Dietary Allowance. Specimens of A. dubius from the three sites showed that they could tolerate Hg, sequester it from the soil, and translocate it to the shoots. Cr could only be removed from the soil and stored in the roots, with limited amounts translocated to the aerial parts. Pb, As, Ni, and Cu have some degree of transportability from the soil to the roots but not to aerial parts. The ability of A. dubius to be considered for phytoremediation has to be viewed with caution because translocation of the metals to the aerial parts of the plant is limited.
... Bioconcentration factor is used as an index to determine the quantity of metal extracted by the plant from soil (Mellem., et al. 2009). The Bioconcentration factor (BCF) is a measure of the plant's ability to absorb and accumulate metal from its growth medium which in this case is soil. ...
... It was asserted by [5] that higher BCF value is an indicator of plant species' suitability for phytoextraction. BCF values 2 were regarded as high values [22]. ...
... A TF value < 1 is an indicator of metal accumulation and storage in root. While TF value > 1 indicate translocation to aerial part of plant [22]. Hence the plant is suitable for phytoremediation. ...
Artisanal mining for Gold in Zamfara state of Nigeria led to massive contamination of the environment with lead (Pb) leading to poisoning and death. The approach for the clean-up involves excavation of the soil and dumping it somewhere which is a temporary solution that is equal to postponement of the reckoning day. The aim of this study was to evaluate the phytoremediation potential of some plants as a cheaper solution to this problem. The treatments consisted of three plant species (Amaranthus cruentus, Brassica oleracea var. capitata and Helianthus annus) factorially combined with four soils (the top soils of Regular Agricultural soil from BUK, Lead (Pb) contaminated soil from Zamfara, Soil from Sheka area peri-urban garden along the banks of Salanta stream contaminated with tannery effluents from Sharada Industrial Estate and BUK soil artificially polluted with a standard addition of Nitrate salts of Pb, Cd, Cr and Ni at the rate of 200 mg/kg for Pb and Cr, and 40 mg/kg for Ni and Cd), all laid out in a Completely Randomized Design (CRD) and replicated three times. Results have shown that Amaranth emerged as the plant with the highest accumulation of metal in its tissue. Across the three plant species, Pb is the most highly accumulated metal and Ni is the least concentrated. The Bioconcentra-tion Factor (BCF) index >2 was recorded for Cr, Mn, and Cd in the tissue of Amaranth. The Translocation Factor index >1 was recorded for Mn, Cd, Pb, Cr, Ni, and Zn. Cabbage had relatively high BCF index for some metals, meaning it can sequester Cd, Cr, Mn and Pb. The TF index >1was recorded for all of the metals. The implication of this is that Cabbage had the ability to translocate all the tested metals. Sunflower has also accumulated a good amount of the various heavy metals. BCF index >2 was recorded with Cd, Cr, Cu, Mn and Pb. But the TF index >1 was seen across all the metals. Soil from Zamfara was observed to produce plants with significantly higher Pb in the shoot, while differences in metal content in the shoot tissue among plant species was not significant.
... Plants species possess detoxification mechanisms, which enable them to uptake some anthropogenic toxic materials when absorbing soil nutrients (Pourrut et al. 2011;Sytar et al. 2013;Alagić et al. 2015). Heavy metals (HMs) are among the most important soil polluters, which can transfer from soil to plant roots and consequently other aboveground plant parts with essential (Cu, Co, Mn, Fe, Zn and Ni) and non-essential (e.g., Cd, Cr, Hg, Pb, As) roles (Clemens 2006;Mellem et al. 2009;Vamerali et al. 2010). ...
... mg/kg-DW. Although Zn is one of the most important plant essential metals (Mellem et al. 2009;Vamerali et al. 2010), here the mean Zn concentrations in the roots and AGPs were lower than Cd and Cu. Conversely, in Bora et al. (2015), the ranking order of HMs in aboveground parts of grapevine (cv Fetească albă, Fetească regală and Riesling Italian) occurred in the following order: Cu > Zn > Ni > Pb > Co > Cd, and Probst et al. (2009) stated that Zn is easily accumulated in green tissues like leaves. ...
... This implies that the roots absorbed the least Pb and Cr and then had the weakest correlation coefficients between the roots and the grapevine AGPs ( Fig. 2 and Table 1). In line with these findings, Mellem et al. (2009) and Tiwari et al. (2009) found that Cr and Pb are not easily transferred to aboveground plant parts and mainly being stored in root cells. Similar to these findings, Vystavna et al. (2015) reported a significant positive relationship between Cr contents in soils and roots, but natural plant barriers in the mechanisms of Cr do not allow excessive contents of Cr into the aerial parts (Ko et al. 2007). ...
Grapevine varieties possess desirable characteristics for phytoremediation purposes. We investigated the potential of grapevine cv Askari in phytoremediation of heavy metal (HM) pollutions. In total 80 grapevine seedlings were exposed to four levels of HM stress (mild, low, moderate, and severe) in greenhouse condition during two growing years (2018 and 2019). The HM concentrations (Zn, Cu, Cd, Cr, and Pb) were subsequently determined in the soils, roots, and grapevine aboveground parts (AGPs), and then phytoextraction and phytostabilization potential assessment indices, i.e., biological absorption coefficient (BAC), bioconcentration factor (BCF), and translocation factor (TF), were calculated. Results led to ranking of the cumulative concentration order of the HMs, i.e.: soils (3476.6) > AGPs (1418.8) > roots (562.2) mg/kg-DW. The mean concentrations ranking order of studied HMs were in soil: Cu (1184.8) > Pb (865.5) > Cd (803.2) > Cr (623.0) > Zn (277.9) mg/kg-DW; roots, Cu (242.0) > Cd (239.5) > Zn (188.8) > Pb (63.5) > Cr (17.2) mg/kg-DW; and AGP environments, Cu (910.2) > Cd (322.9) > Zn (160.3) > Pb (152.9) > Cr (25.3) mg/kg-DW. Principal component analysis results demonstrated the same distribution pattern for the studied HMs between soil, root, and AGP environments, and the highest correlation coefficients were found for Cu, Zn, and Cd. Based on the obtained results (Cu-BAC (> 1), Zn-BCF (> 1), Zn-TF (< 1), Cu-AGP mean concentrations (> 1000 mg/kg-DW), and Cd-AGP mean concentrations (> 100 mg/kg-DW)), it can be concluded that grapevine cv Askari possesses potentials for phytoremediation purposes of Cu, Zn, and Cd. These results were acquired in a greenhouse environment and under controlled conditions; we suggest that the phytoremediation potential of this grapevine variety be assessed in a contaminated vineyard environment as well.
... To evaluate the potential of plant species for phytoextraction, the Translocation Factor (TF) was considered. This ratio is an indication of the ability of the plant to translocate metals from the roots to the aerial parts of the plant [18]. It is represented by the ratio: ...
... The highest translocation factor 4.952 in 100% contaminated soil for copper shows the plant transfer more Cu pollutants than others in the scrapheap soil. The high translocation factor in all metals revels that it mitigates fireworks' pollutants and make the environment harmless to the agriculture [18]. The more translocation factor of metals shows the plant tolerance mechanism have involved neutralizing toxic elements and reach to the cytoplasm, i.e. metabolic processes and cell membrane were protected against damage [19]. ...
... Findings from different experiments have indicated that Amaranthus has a higher proximate composition than commonly consumed food crops, such as corn (Zea mays), buckwheat, rye, and rice [15]; comparable nutritive characteristics to commonly patronized vegetables, e.g., spinach (Spinacia oleracea L.) [31]; equivalent nutrient content to some fodder crops, such as barley, maize, and wheat [46]; and is rich in extremely rare amino acids (e.g., lysine and tryptophan) that could replace animal protein and supplement human diets with moderate-quality amino acids [47,48]. Metabolic diseases, such as diabetes, ulcers, congestive cardiac, liver, and renal failure, cancer, helminthic infections, and most degenerative diseases, such as ageing hypertension, atherosclerosis, obesity, and being chronically underweight are induced by damages done to cells and tissues by free radicals [17,[49][50][51][52]. Several species of Amaranthus are reported to play important roles in the regression of oxidative stress-induced disorders due to their ability to scavenge free radicals, thereby neutralizing their degenerating consequences [13,22,[53][54][55][56][57]. ...
... The use of plants to stabilize, degrade, and extract pollutants has become a safer, cost-effective, and complementary green technique compared to engineering-based approaches, as plant tissues serve as channels for uptake, chelation, and volatilization of pollutants [62][63][64]. It is also common knowledge that green plants sequester carbon dioxide and other gaseous biomolecules, bringing about non-invasive environmental clean-up [54,59,61,65]. Thus, several species of Amaranthaceae have been implicated in-efficient CO 2 sequestration and phytomining of heavy metals introduced into the environment due to natural processes or anthropogenic activities [34,60,66,67]. ...
Leafy vegetables promote reparation of energy loss due to oxidative stress, and they have the potential to alleviate hunger and malnutrition as well as other forms of metabolic imbalance ravaging the world. However, these vegetables are underutilized, despite the fact that they harbor essential minerals needed for critical cellular activities. As amaranth is one of the earliest vegetables reputed for its high nutraceutical and therapeutic value, in this study, we explored research on the Amaranthus species, and identified areas with knowledge gaps, to harness the various biological and economic potentials of the species. Relevant published documents on the plant were retrieved from the Science Citation Index Expanded accessed through the Web of Science from 2011 to 2020; while RStudio and VOSviewer were used for data analysis and visualization, respectively. Publications over the past decade (dominated by researchers from the USA, India, and China, with a collaboration index of 3.22) showed that Amaranthus research experienced steady growth. Findings from the study revealed the importance of the research and knowledge gaps in the underutilization of the vegetable. This could be helpful in identifying prominent researchers who can be supported by government funds, to address the malnutrition problem in developing countries throughout the world.
... When the BAF > 1, it indicates that the plant species have the potential to hyperaccumulate chemical species from soil or growing media (Mganga 2014). On the other hand, TF is used to assess the mobility of metals within different plant parts, and it will reflect the plant's ability to translocate metals to above-ground parts (Mellem et al. 2009). If the TF is greater than 1, it implies that the metals are being actively translocated from roots to shoots which is indicative that such plant is a good candidate as a phytoextraction agent especially when the BAF > 1 (Singh et al. 2010). ...
... On the other hand, the TF for Cr and Mn was greater than 1 but the BAF < 1 would imply that these metals could be transported much easier into the above-ground parts. The higher the bioaccumulation factor the more suitable the plant is for phytoextraction; a higher bioaccumulation factor is considered to be greater than the value two (Mellem et al. 2009). According to Chehregani and Malayeri (2007), Euphorbia cheiradenia is one of the plant species which can accumulate higher amounts of Pb, Ni, Cu, Cd, and Zn which were found in an area considered to be a lead waste pool in Iran. ...
Discarding fly ash from a coal power plant into a dumpsite does not only contribute to deforestation and loss of productive land but also leads to contamination of air, soil, and groundwater. Therefore, fly ash should be managed properly to avoid the migration of contaminants. One management option is phytoremediation using adapted plants and as a prerequisite, there is a need to identify suitable plants that can be used for revegetation of fly ash dumpsites. To identify prospective plants, a survey was carried out by assessing the plants growing in Morupule B fly ash dumpsite based on their ability to accumulate heavy metals and their bioconcentration (BAF) and translocation factors (TF). Of the twenty-two-plant species growing in the fly ash dumpsite of Morupule B power plant station, N. glauca is a potential phytoextraction agent for Cu (TFCu = 1.02; BAFCu = 2.16) and Pb (TFPb = 1.38; BAFPb = 1.65); P. burchellii for Pb (TFPb = 1.61, BAFPb = 0.9) and Zn (TFZn = 1.35; BAFZn = 5.74); I. pes-tigridis for Pb (TFPb = 1.35; BAFPb = 1.56) and Zn (TFZn = 1.62; BAFZn = 7.43); A. pungens for Cr (TFCr = 1.22; BAFCr = 0.11), Cu (TFCu = 2.18; BAFCu = 1.14), and Zn (TFZn = 1.04; BAFZn = 1.44); E. hirta for Zn (TFZn = 1.54, BAFZn = 2.44); A. spinosus for Pb (TFPb = 1.29; BAFPb = 1.55); C. dactylon for Cu (TFCu = 1.86; BAFCu = 1.07) and Zn (TFZn = 1.00; BAFZn = 2.46); and D. aegyptium for Pb (TFPb = 1.19; BAFPb = 2.57). Other plants growing in the fly ash dumpsite are potential candidates for phytostabilization as they can tolerate a high concentration of metals and low essential nutrients. Also, different plant groups variably modified the pH, EC, OM, and exchangeable fractions of metals in the rhizosphere wherein grasses can increase the OM at higher rates, and it has a higher capacity to acidify and solubilize heavy metals in the rhizosphere leading to higher EC and available metals compared to other plant groups. Overall, the information presented is useful in identifying plants or their combinations for the phytoremediation of fly ash and other heavy metal-polluted environments.
... Translocation Factor (TF) is a ratio of ketal concentration in plant shoot and metal concentration in plant roots. Bio-Concentration Factor (BCF) is a ratio of metal concentration in plant roots and metal concentration in soils (Mellem et al., 2009). TF indicates the rate of transfer of heavy metals from plant roots to plant shoots, while BCF determines the plant ability in absorbing heavy metals. ...
... Bio-Concentration Factor (BCF) is a common index usually used in determining and evaluating the ability of a plant to extract heavy metals. Plants with the BCF value higher than 1 are categorized as hyperaccumulators, while plants with BCF value lower than 1 are considered as accumulators (Mellem et al., 2009;. The metal accumulator plants have different ways of storing heavy metals in their body. ...
Heavy metal contamination was an environmental and human health problem all over the world. Cadmium is the most hazardous heavy metals due to its high mobility and toxicity at low concentrations. Lead (Pb) also belongs to the hazard element caused by its prolonged persistence in the soil. This study aimed to develop the remediation techniques on polluted land, i.e. a combination of biochar and indigenous plant. The biochar was produced by slow pyrolysis method. This experiment was conducted at the farmland at Sumber Brantas, Malang, East Java. We used rice husk and tobacco waste biochar, and Eleusine indica (L.) Gaertn and Rorippa sylvestris (L.) Bess. as remediator plants. The results showed that rice husk biochar had a significant effect on pH value and potassium content (p = 0.0001; p=0.0004). On the contrary, the soil nitrogen content, soil organic-C content, and soil cation exchange capacity applied with tobacco waste biochar application were higher than that applied with rice husk biochar (p = 0.03; p=0.00001; p = 0.00001). The improvement of soil characteristics increased the growth of Eleusine indica and Rorippa sylvestris as indicated by the plant height and biomass. The addition of biochar could promote the growth of remediator plant and enhanced the accumulation of Pb and Cd in the plants. Mixtures of rice husk biochar and tobacco waste biochar caused Eleusine indica more effectively absorbed heavy metals than Rorippa sylvestris on all types of biochar treatments; Eleusine indica absorbed Pb and Cd higher than Rorippa sylvestris as shown by Pb and Cd contents in the soil.
... The root-shoot ratio is an indication of plant ability to translocate HMs from its root to aerial parts (shoot) (Mellem et al., 2012). Heavy metals accumulated by plants largely stored in the roots are indicated by TF values less than 1, however, the values greater than 1 indicates higher translocation of HMs to the aerial parts (shoot) (Mellem et al., 2009). The TF of T. latifolia for other HMs has already been well documented for different heavy metals and found in line with present findings such as for Ni, Cd, Mg and Zn > 1 and for Cr, Cu, Fe, Mn 1 (Hazra et al., 2015). ...
... The TF of T. latifolia for other HMs has already been well documented for different heavy metals and found in line with present findings such as for Ni, Cd, Mg and Zn > 1 and for Cr, Cu, Fe, Mn 1 (Hazra et al., 2015). Similar to TF, BCF root and shoot of T. latfifolia in present study is parallel to the findings of Hazra et al. (2015) and Grisey et al. (2012) for other HMs such as Cd, Cu, Mn, and Fe ! 2. The higher BCF !2 is considered as high and an indication of plant suitability for the phytoremediation of that HM (Blaylock et al., 1997;Mellem et al., 2009). ...
Chelate-assisted phytoextraction by high biomass producing macrophyte plant Typha latifolia L. commonly known as cattail, is gaining much attention worldwide. The present study investigated the effects of Lead (Pb) and Mercury (Hg) on physiology and biochemistry of plant, Pb and Hg uptake in T. latifolia with and without citric acid (CA) amendment. The uniform seedlings of T. latifolia were treated with various concentrations in the hydroponics as: Pb and Hg (1, 2.5, 5 mM) each alone and/or with CA (5 mM). After four weeks of treatments, the results revealed that Pb and Hg significantly reduced the plant agronomic traits as compare to non-treated plants. The addition of CA improved the plant physiology and enhanced the antioxidant enzymes activities to overcome Pb and Hg induced oxidative damage and electrolyte leakage. Our results depicted that Pb and Hg uptake and accumulation by T. latifolia was dose depend whereas, the addition of CA further increased the concentration and accumulation of Pb and Hg by up to 22 & 35% Pb and 72 & 40% Hg in roots, 25 & 26% Pb and 85 & 60% Hg in stems and 22 & 15 Pb and 100 & 58% Hg in leaves respectively compared to Pb and Hg treated only plants. On other hand, the root-shoot translocation factor was ≥1 and bioconcentration factor was also ≥2 for both Pb & Hg. The results also revealed that T. latifolia showed greater tolerance towards Hg and accumulated higher Hg in all parts compared with Pb.
... In this context, phytoremediation can be considered as economical and very valid option for lightly polluted areas (Kumar et al., 1995) [47] . Phytoremediation can be accomplished by several means including phytoextraction, phytostabilization, phytovolatilization and phytodegradation (Mellem et al., 2009) [60] . Bio-sorption is one of the processes which involves a solid (sorbent) and a liquid (solvent) which containing dissolved materials attracted by affinity, through several mechanisms, involving chemisorption, physisorption, complexation, ionexchange, chelation and entrapment (Côrtes et al., 2015;Kang et al., 2016;Mahajan and Sud, 2012;Wang et al., 2017) [14,42,56,102] . ...
... In this context, phytoremediation can be considered as economical and very valid option for lightly polluted areas (Kumar et al., 1995) [47] . Phytoremediation can be accomplished by several means including phytoextraction, phytostabilization, phytovolatilization and phytodegradation (Mellem et al., 2009) [60] . Bio-sorption is one of the processes which involves a solid (sorbent) and a liquid (solvent) which containing dissolved materials attracted by affinity, through several mechanisms, involving chemisorption, physisorption, complexation, ionexchange, chelation and entrapment (Côrtes et al., 2015;Kang et al., 2016;Mahajan and Sud, 2012;Wang et al., 2017) [14,42,56,102] . ...
This paper provides a broad review of the process of heavy metal entering to food chain via different sources. A thorough study was conducted on heavy metals including possible sources, parameters control the plant availability in micro environment, mechanism of taking up by plants, translocation through the plants, extent of heavy metals in organically amended soils, impact of organic fertilizer on heavy metal availability and finally, the novel strategies available for removal of heavy metals from the environment. Metal contamination issues are becoming increasingly common in Sri Lanka and everywhere. Heavy metals such as cadmium, copper, lead, arsenic and chromium are major environmental pollutants, particularly areas in high anthropogenic activities. Agricultural activates have been identified as major source of heavy metals entering to food chain and, organic agriculture has been popularized throughout the world recent past due to safety and environmental concerns. However, limited evidence exists for comparison heavy metal content in the products of conventional and organic systems and, a thorough analysis is required to confirm the safety of organic products.
... The translocation factor (TF) is the ratio of metal concentration in the leaves & stems and the metal concentration in the root (Mellem et al., 2009). It is calculated as: ...
Hyperaccumulator plants, such as Ipomoea carnea, are known for their ability to accumulate heavy metals in their aerial parts. This study aimed to determine whether I. carnea is an iron hyperaccumulator. Ten sites within the Ramgram Municipality, Nawalparasi (west) district were selected randomly- five near industrial areas and five away from industries. Two plants from each site were harvested along with the soil samples nearby, following the standard protocols for collection. After sun-drying, the plant samples for four weeks and soil samples for three days, iron concentrations in roots, shoots, leaves, and soil were measured with an atomic absorption spectrophotometer using ashing and wet acid digestion. The results showed a significant correlation (r = 0.728, p < 0.05) between the root iron concentration and the total iron in the plant. The analysis of variance revealed differences in iron accumulation in the roots, stems, and leaves of I. carnea. In the industrial areas, the biological absorption coefficient was 0.12 as compared to 0.08 in the non-industrial areas, indicating I. carnea is a low accumulator. The bioconcentration factor and the translocation factor were observed to be higher in the industrial areas. Overall, I. carnea was not found to be an effective iron hyperaccumulator in the study area, as indicated by the biological absorption coefficient, bio-concentration factor, and translocation factor values. In addition, the soil iron concentration was within the acceptable limit in the study area.
... The bioconcentration factor (BCF) (Souza et al. 2012) represents the ability of a certain metal in plant stems and leaves or roots (Mellem et al. 2009;Zacchini et al. 2009). The bioconcentration factor of plant aerial parts is calculated by formula (1): where [Metals] Shoot represents the total concentration of heavy metals in plant stems and leaves; ...
Aims
HDS sediment is a type of solid waste produced when the high-concentration mud method (HDS) is adopted to treat acid wastewater from copper mines. It can rationally utilize sediment resources by using phytoremediation, which plays a role in the ecological restoration of mines.
Methods
To reveal the effect of different phytoremediation on the heavy metal, enrichment capacity and microbial diversity of the HDS sediments of copper mines, in this experiment, the HDS sediments of a copper mine without phytoremediation were selected as the control group, while the sediments of black locust (Robinia pseudoacacia), slash pine (Pinus elliottii Engelmann) and Chinese white poplar (Populus tomentosa Carr.) were used as test groups to analyze the physical and chemical properties, heavy metal pollution and bioaccumulation capacity of HDS sediments under three phytoremediation.
Results
The results show that different phytoremediation can reduce the sediment's conductivity and adjust the sediment’s pH value to the range suitable for plant growth. The BCFShoot and BTF values of Chinese white poplar to Cd and Zn and slash pine to Pb were both greater than 1.
Conclusions
As discovered from the bioconcentration coefficient and biotransport coefficient results, Chinese white poplar is a Cd-enriched and Zn-enriched plant, while slash pine is a Pb-enriched plant.
... In general, translocation to the aerial parts of the plant is indicated by translocation factor (TF) values greater than 1. TF was calculated using the given formula (Mellem et al. 2009;Chandra et al. 2018): ...
The glass manufacturing industry produces hazardous effluent that is difficult to manage and causes numerous environmental problems when disposed of in the open. In this study, an attempt was made to study the phytoremediation feasibility of water lettuce (Pistia stratiotes L.), a free-floating aquatic macrophyte, for the removal of six heavy metals from glass industry effluent (GIE) at varying concentrations (0, 25, 50, 75, and 100%). After a 40-day experiment, the results showed that 25% GIE dilution showed maximum removal of heavy metals i.e., Cu (91.74%), Cr (95.29%), Fe (86.47%), Mn (92.95%), Pb (87.10%), and Zn (91.34%), respectively. The bioaccumulation, translocation, and Pearson correlation studies showed that the amount of heavy metals absorbed by vegetative parts of P. stratiotes was significantly correlated with concentrations. The highest biomass production, chlorophyll content, relative growth rate, and biomass productivity were also noted in the 25% GIE treatment. Moreover, the multiple linear regression models developed for the prediction of heavy metal uptake by P. stratiotes also showed good performance in determining the impact of GIE properties. The models showed a high coefficient of determination (R² > 0.99), low mean average normalizing error (MANE = 0.01), and high model efficiency (ME > 0.99) supporting the robustness of the developed equations. This study outlined an efficient method for the biological treatment of GIE using P. stratiotes to reduce risks associated with its unsafe disposal.
... A TF<1 indicates an excluder character of the plant for the target metal and a TF>1 corresponds to a plant with the ability to translocate the target metal from roots to shoots. In the case of BCF, a value higher than 1 corresponds to a plant with the ability to accumulate the target metal in a determined part of the plant [24,25]. The removal efficiency will also be calculated to obtain the total mass of the target metal removed from tailings according to Equation (3). ...
: In Chile, most tailings impoundments are in Northern and Central Chile, 20% of them are abandoned. Municipal budgets to manage these environmental liabilities are very limited and the use of native and endemic plant species to remove heavy metals from tailings is a low-cost alternative. Ex-situ phytoremediation experiments were conducted over seven months to evaluate the potential of Lycium chilense and Haplopappus foliosus to remove copper and lead from mine tailings. The results indicate that both species can concentrate high levels of both elements and they present removal efficiencies for Cu close to 50%. The best performance was presented by Haplopappus foliosus, accumulating higher concentrations of both metals than Lycium chilense. Also, it presents a bioconcentration over 1.
... Evenness was found to be higher in Hydrocarbon exploration site than the adjacent site.The BCF specifies the ability of the plant to absorb the trace element in the plant with concern to the trace element concentration in the media 25 . Values above 1 are high for the translocation factor, which is a measure of the concentration of metal in aerial portals to that in roots 15 . It was also observed that all the plants found in both the sites have some level of the metals in either their root or shoot parts. ...
Phytoremediation is the use of plants to remediate an area of any types of contaminants. This technique is becoming popular in recent years due to its cost effective and environment friendly nature. The present study was conducted in a hydrocarbon exploration site of Tripura to determine the types of plants present in the area and to check the concentration of elements like iron, chromium, and sulphur in the plants that are found during the study. The adjacent site was also explored for comparative analysis and structural diversity. It was observed that only herb species was found in the hydrocarbon exploration area. There was no shrub species in the area. However, in the adjacent area both herb and shrub species were found. The element content in the plants shows that all the plants absorbed some amount of the mentioned elements in their root and shoot part. The study is significant as no earlier study of such kind has been conducted in Tripura.
... where C plant part is the metal concentration (mg kg −1 , dry matter) detected in the selected plant part and C soil is the metal concentration (mg kg −1 , dry matter) detected in the growing media (Li et al., 2007;Rezvani & Zaefarian, 2011). The translocation factor refers to the ratio of metal concentration in selected aboveground plant organs (C aboveground plant part ) and metal concentration in roots (C roots ) (Malik et al., 2010;Mellem et al., 2009): ...
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.
Supplementary Information
The online version contains supplementary material available at 10.1007/s10661-023-11422-3.
... Translocation factor (TF) indicators as widely applied to evaluate the trace element accumulation in the plant parts were calculated. The translocation factor (TF) refers to the ratio of the total element concentration of leaves (C leaves ) and element concentration of roots (C roots ): C leaves /C roots [24]. ...
Carex species are widely used in many parts of the world and contain a large number of ecologically diverse species. Among the Carex species, some of them are known to be glycophytes, while others are halophytes. Carex morrowii Boott (Cyperaceae) is resistant to trample through their root structure and has an essential ornamental value in the landscape with their leaves. However, no information was found about the level of salinity tolerance/sensitivity of the Carex morrowii among these species. In the present study, changes in trace element contents (Na, K, Ca, Cu, Mn, Mg, Ni, Fe, P, Zn, and N) and their transport from roots to leaves, osmotic regulation, alterations in chlorophyll and carotenoid contents, nitrogen assimilation (nitrate reductase activity; NRA) and total soluble protein content in both roots and leaves of Carex morrowii under different salinity concentrations (50 mM, 100 mM, 200 mM and 300 mM NaCl) were examined in detail. Our study provides the first detailed data concerning the responses of leaves and roots and the determination of the level of salinity tolerance/sensitivity of the Carex morrowii. The K⁺/Na⁺ ratio was preserved up to 200 mM NaCl, and accordingly, the element uptake and transport ratios showed that they could control moderate NaCl levels. Ca homeostasis that is maintained even in 200 mM NaCl concentration can be effective in maintaining the structural integrity and selective permeability of the cell membranes, while 300 mM NaCl concentration caused decreased photosynthetic pigments, and deterioration in element content and compartmentation. Moreover, these data suggest that plant parts of Carex morrowii respond differently against varied levels of salinity stress. Although the decrease in NR activity at 200 mM and 300 mM NaCl concentrations in the leaves, NR activity was maintained in the roots. Consequently, Carex morrowii is moderately tolerant to salinity and the carotenoid content and osmotic regulation of Carex morrowii appears to be instrumental in its survival at different salinity levels. Especially the roots of Carex morrowii have a remarkable role in salinity tolerance.
... Pb (Figlioli et al., 2019).Figlioli et al. (2019) reported that the increase in chlorophyll biosynthesis in Pb treated plants was related to increased photosynthetic protein level, Rubisco (ribulose-1,5bisphosphate carboxylase-oxygenase). In addition, the chloroplasts had a preserved ultrastructure after Pb exposure with no alteration in thylakoid organization(Figlioli et al., 2019) which might be due to a limited Pb translocation to the aboveground parts(Mellem et al., 2009). Chlorophyll a fluorescence: The evaluation of the quenching parameters in L. crithmoides plants treated with increasing Pb concentrations showed that Fv/Fm, Fv'/Fm', ETR and all of the energy fluxes (ABS/RC, TRo/RC, ETo/RC and DIo/RC) were not affected by Pb stress and remained stable as the control (p < 0.05; table 1). ...
Review Proccess: Peer review The effectiveness of chlorophyll a fluorescence as a quick tool to detect the effect of Pb-stress on Limbarda crithmoides and Helianthus annuus species, when exposed to increasing Pb concentrations (0-500 µmol.L-1) for 45 days, was evaluated. The chlorophyll level in plant leaves, as well as the fresh weight and Pb content in the shoots and roots in both plant species, were also determined. L. crithmoides did not show any significant variation in photochemical quenching parameters and energy fluxes in all Pb concentrations despite the change in OJIP plot of 100 µmol.L-1 Pb. In addition, a significant increase in chlorophyll a content was noted along with an increase in the biomass production. However, in H. annuus, Pb stress increased energy absorption, dissipation and trapping and decreased energy transport and electron transport rate. In addition, the OJIP curve showed a notable modification at 300 and 500 µmol.L-1 Pb, without significant changes in the chlorophyll contents and in the biomass production under all Pb concentrations. Results also revealed that Pb was accumulated in the shoots and roots of L. crithmoides and H. annuus and the accumulation was more notorious in the roots of the treated plants. Lead exhibited different influence on the photosystem II performance in both species, thus, the evaluation of chlorophyll fluorescence was a very efficacious tool to reflect the physiological status of L. crithmoides and H. annuus under Pb stress.
... TF and BCF are presented by Equations (1) A value of BCF greater than 1 indicates the potential use of a plant species for phytoremediation. In contrast, a TF > 1 shows the ability for the metal to be translocated from roots to shoots and vice versa; if it is less than 1 (TF < 1), the species is a metal excluder [39][40][41][42][43][44]. ...
Mining activities have been a part of the history of Chile since time immemorial, generating pollution and environmental liabilities. Due to the lack of regulation, many tailings are deposited close to rivers or/and on unstable ground, near which towns have been built, generally in locations with no budget for their treatment. This study tested three plant species from Northern and Central Chile to remove total chromium, nickel, and zinc from tailings: Solidago chilensis, Haplopappus foliosus, and Lycium chilense, which complements the few existing studies on heavy metals removal with native or endemic Chilean shrubs. The experiments were conducted ex situ, and the initial and final concentrations of metals were determined in tailings and plants to obtain the removal efficiency, translocation and bioconcentration factors. Among these species, the best performance was obtained using Solidago chilensis, achieving removal efficiencies of 24% for Cr, 19% for Ni, and 17% for Zn, showing the ability to phytostabilize chromium and the higher resistance concerning the toxicity threshold. Haplopappus foliosus and Lycium chilense presented a slight tendency to stabilize chromium. Only Solidago chilensis showed little ability to extract Zn.
... The work sufficiently demonstrated that there is a connection between the polyphenolic content of extractives and their antioxidant properties. As a result, this may be used as a health supplement (Mellem et al., 2009;Rodríguez et al., 2011;Vargas-Ortiz et al., 2021). ...
Plants have long been a significant source of phytomedicines for human health, so it is important to look into the different phytoconstituents that they contain. The existence of secondary metabolites has a number of pharmacological and biochemical effects, according to the phytochemical study of Amaanthus dubius. Preliminary analyses of Amaranthus dubius with ethanol, methanol, acetone, ethyl acetate, chloroform, and hexane were conducted to identify the following phytocho-chemical extracts: alkaloids, flavonoids, phenols, tannins, saponins, cardiovascular glycosides, steroids, proteins, and carbohydrates. The results of this study indicated that Amaranthus dubius methanol extracts with the highest amount of secondary compounds are essential for human health. The methanolic extract of Amaranthus dubius had reducing activity, but it was lower than L-ascorbic acid, a reference antioxidant, and the extractives increased the reducing activity as the extract concentration increased. Higher absorbance means further reducing strength. The present study revealed that methanolic extract of Amaranthus dubius had significant free radical scavenging potential.
... Translocation factor is the ratio between the concentrations of contaminant in the aerial part of the plant to that in the root. This ratio is an indication of the ability of the plant to translocate the contaminant from the roots to the aerial parts of the plant [13]. It is represented by a ratio. ...
Arsenic (As) is a highly toxic metalloid present naturally in the earth’s crust. In developing countries apart from drinking water, one major reason for arsenic toxicity among human beings is through contaminated crops and vegetables. The nutritional quality of the crops and vegetables grown in the arsenic-infested area gets compromised. A major challenge is to protect the vegetables and crops from arsenic contamination. Attempts have been made through different remediation technologies. The present research is designed to reduce the arsenic load in arsenic-sensitive (non-hyperaccumulator) plants by co-cultivation with hyperaccumulator plants, thus saving food chain contamination to humans. In the present study, done in potted plants, it has been found that co-cultivated B. oleracea has 1.5 times decreased arsenic translocation compared to the control plant; on the contrary, hyperaccumulator B. juncea showed higher translocation. Plant health biomarkers like total chlorophyll and protein contents were two times higher in co-cultivated B. oleracea compared to the As-treated control which actually seconds the fact of less translocation in the co-cultivated plants. The stress marker like proline content, super oxide dimutase, and malondialdehyde content showed a decrease in co-cultivated B. oleracea compared to the control plant grown in arsenic-infested soil which again reflected less stress in co-cultivated plants. From these findings of the research, we can hypothesize that hyperaccumulator B. juncea might save B. oleracea from arsenic-induced toxicity when co-cultivated and thus can save food chain-mediated contamination to human beings.
... Oat plant is also used for assessment of toxic elements among higher plants (Chang et al. 1997) under inadequate low pH conditions in soil (Loureiro et al. 2006;Bilski and Foy 1987;Small and Jackson 1949). Mellem et al. (2009) reported that Amaranthus dubius plant is more capable of removing the toxic elements by roots in contaminated soil, but toxic elements such as Cr, Ni, As, Pb, and Cu could not uptake and absorb in plant shoot. Environmentally friendly techniques such as bioassay and transgenic techniques have been recommended to evaluate the genotoxic potential effects of contaminants on plants such as micronucleus (MCN) induction and random-amplified polymorphic DNAs (RAPDs) techniques (Angelis et al. 2000;Arkhipchuk et al. 2000;DeWolf et al. 2004;Liu et al. 2005). ...
Contamination of plants with toxic elements (TEs) is a renowned environmental issue worldwide. The rapid increase in population and high food demand give rise to several pollutants that finally contaminate the ecosystem. Plants cultivated on contaminated soils show a reduction in growth, nutrient uptake, and yield. The concentrations exceeding the optimal levels in plants have both direct and indirect adverse effects on plants. The contamination of toxic elements not only reduces the plant growth and development but also affects other activities such as photosynthesis, plant mineral nutrition, and decreases the activities of some enzymes. This chapter addresses the issues related to the causes, uptake, transmission, and effects of toxic elements on plant nutrients when grown on contaminated soils. According to the available literature, toxic elements have great impact on plant growth and nutritional contents; therefore, plants cultivated on metal-polluted soil are nutrient scarce with reduce plant growth.
... respectively. BCF values > 2 were regarded as high values 10 . Out of the 18 plants found in both the sites, 8 plants have BCF shoot values more than 2 and 5 plants have BCF root values exceeding 2. Plants with BCF value (generally > 1) are considered as suitable for phytoextraction experiment 3 . ...
The plants found in the hydrocarbon exploration sites needs to be identified and the concentration of different minerals need to be determined. The present study has been conducted to determine the phosphorus content in the soil and plants of hydrocarbon exploration site. The phosphorus content in the soil and plants found in the adjacent site were also determined. The highest phosphorus content in root and shoot was recorded in Cynodon dactylon (L.) Pers. and Lantana camara respectively of ONGC Kanchanmala Adjacent site. Ageratum conyzoides L. of ONGC Kanchanmala site has the lowest root and shoot phosphorus content. The Translocation factor and Bioconcentration factor was also calculated. The study will give an idea of the phosphorus content in the soil and plants found in the two sites. The plants which have highest phosphorus concentration in their tissue can be used in future experiment in phosphorus contaminated sites.
... For this factor, the values lower than 1 indicate that metals are accumulated by plants but stored in the roots. The values higher that 1 indicate translocation to the aerial parts (Mellem et al. 2009). The TF values, for all the metals examined varied from <0.001 to 3.7, and similar to BAF with the lowest for REE (<0.001-0.10) ...
Background and aim
The presence of chlorides in soils, e.g., from de-icing salts may change metal availability to plants.
Methods
To assess the role of de-icing chlorides on bioavailability of metals, the samples of the rhizosphere soils, roots and shoots of Juncus effusus L. were collected monthly from April to June of 2019 in the vicinity of roads and analyzed for trace (Ag, Cd, Co, Cu, Pb, Zn) and rare earth elements (from La to Lu).
Results
Concentrations of Cl ⁻ were distinctly higher in the shoots than in the roots. Apart from Cd, the concentration sequence of the other metals was as follows: rhizosphere soils>roots>shoots. The bioaccumulation and translocation factors indicated that Cd was the most preferably transported to the shoots as opposed to Ag, Co, Pb and REEs that showed a very low translocation potential. Negative correlations, which were noted between Cu and Co in the shoots and Cl ⁻ in soils, revealed their role in salinity stress alleviation. All soil samples showed a positive anomaly of Ce and a negative anomaly of Eu, whereas the shoots showed in turn a negative anomaly of Ce and a distinct positive anomaly of Eu. The lowest salinity factors (K/Na, Ca/Na) of the shoots resulted from an increase of salinity in J. effusus by higher sodium concentrations derived from de-icing NaCl.
Conclusions
De-icing agents may change the uptake of other elements. In natural habitats, the factors affecting this process include: type of element, soil metal concentrations and interactions, and individual plant features.
... The content of Cu in different biomass varies significantly; for example, wheat straw contains 0.06 ppm Cu [17], beech wood contains 43 ppm Cu [17], phyto remed from plants in contaminated sites contains 70 ppm Cu [18], sewage sludge contains 330 ppm Cu [19], chicken litter contains 71 ppm Cu [20], and paper sludge contains 310-450 ppm Cu [21,22]. According to Saarela et al. [16], the pine bark obtained nearby the metal industry in Kokkola, Finland, contained about 515 ppm of Cu. ...
The role of Cu-based phases in combustion processes has boldly emerged with the drastic increase in the waste combustion, sparking the need to update thermodynamic databases for a better understanding and control. In the present work, we have reviewed the content and sources of Cu in selected biomass fuels and ashes, and examined the mechanisms through which it affects combustion processes and the environment. Phase equilibria and thermodynamic properties of phases in the CuCl-CuSO4 system and their effects on the melting behavior of chlorides and sulfates of Na, K, Cu, Pb, Zn, and Fe were investigated. The observed results are presented and discussed.
... Plants for the last two to three decades have been studied for their ability to degrade and sequester organic pollutants in the soil via different constituent parts. The sphagneticola trilobata and amaranthus hypochondriacus have been used to accumulate a variety of toxic substances in the soil [36,37] . For this reason, their proven phytoremediation potential has gained importance in the restoration of polluted soil. ...
... TF represents the index that indicates the ability of the plant to translocate heavy metals from root to shoot biomass [27]. Values of TF less than 1 indicates that the heavy metal accumulates in roots to a greater extent and its translocation to the shoot biomass is poor [28]. ...
Water pollution is recognised as one of the major environmental problems. Floating treatment wetlands (FTW) have emerged as a powerful tool that can help in the revitalisation of polluted waters. This study is set out to assess the feasibility of selected plant species in FTW to accumulate Cr and Ni from water contaminated with low concentrations of both heavy metals. The results showed that all investigated species contained more Cr and Ni in the be-lowground biomass whereby the translocation of these metals into the aboveground parts was very low. Species Phragmites australis had great potential for accumulation of Cr and Ni with significantly higher Cr and Ni concentrations in roots compared to the other investigated species. Furthermore, the present study suggests that species Iris pseudacorus may also have a good potential for removal of both heavy metals, species Canna indica for the accumulation of Ni and species Alissma plantago-aquatica, Menianthes trifoliata and Iris sibirica 'Perry's Blue' for the accumulation of Cr. Future studies should concentrate on the investigation and assessment of phytoremediation potential of the same species growing in water contaminated with higher levels of Cr and Ni.
... Other plants in Brassicaceae family such as Brassica campestris, Brassica oleracea, and Thlaspi caerulescens are also able to accumulate heavy metals to a higher extent (Memon and Schröder, 2009;Rizwan et al., 2018). Mellem et al. (2009) proposed that Cr, Hg, As, Pb, Cu and Ni could be bioremediated using Amaranthus dubius through their root system. Basella alba shows the ability of phytoextraction for Zn, Cu and Ni due to the multi-nucleolus and multi-vacuoles and formation in root cells (Chandra et al., 2018). ...
A R T I C L E I N F O Keywords: Heavy metal Instrumental neutron activation analysis Soil-to-plant transfer factor Target hazard quotient A B S T R A C T The contamination of heavy metals in agricultural ecosystem is one of the most important problems in developing countries as Vietnam. In this study, we investigated the multi-element concentrations in soil, vegetables, soil-to-plant transfer factors and target hazard quotient (THQ) due to the consumption of heavy metals in Ho Chi Minh City, Vietnam. In general, the element concentrations in soil and plants were similar to different studies in the world and in the range of allowable values provided by WHO and the Ministry of Health of Vietnam. The transfer factors indicated the influence of element characteristics and plant genotypes on the accumulation and translocation of elements from soil to plants. It is found that I. batatas, B. alba, A, tricolor, O. basilicum, and B. juncea could be potential candidates for phytoremediation in soil contaminated of heavy metals. The results of individual and total THQ were below unity for Cr, Mn, Fe, Co, Zn, As, and Sb. The total THQ is in the range from 0.11 for R. sativus to 0.84 for B. alba with the average value of 0.43, in which Mn and As are the major contributions to the total THQ with the average values of 75% and 18%, respectively. The safety assessment based on national regulations and THQ indicated that the consumption of investigated vegetables poses no risk to the consumers.
... Unacceptably high levels of Pb (50-21,000 mg/kg) were reported in soil, near the abandoned Edendale mine in South Africa (Oyourou et al. 2019). Mellem et al. (2009) reported 105 mg/kg Cu from domestic and industrial solid waste Editorial responsibility: Jing Chen. sites, in soils sampled in Durban, South Africa. ...
This paper describes an investigation into the accumulation and distribution of Cu and Pb in Helichrysum splendidum, to assess the potential use of the plant in the phytoremediation of Cu- and Pb-contaminated soils. Plants of the same age were exposed to soils artificially contaminated with 10, 50, 100, 500 and 1000 mg/L Cu(II) and Pb(II). Although plant growth was not affected by the presence of Cu, high concentrations of Pb (> 500 mg/L) stunted the plants. Chlorophyll production was slightly reduced when plants were exposed to high concentrations of Cu (> 500 mg/L), whereas all the plants growing in Pb-contaminated soils indicated low levels of chlorophyll. Significant amounts of Cu and Pb were accumulated in the roots, with corresponding bioconcentration factors of > 1. Translocation of Cu to the shoots was restricted for plants growing in > 500 mg/L Cu-treated soils, whereas Pb was translocated to the shoots for all treatments, with translocation factors > 1. The Cu and Pb tolerance mechanism was ascribed to chelation and free radical scavenging, through the production of phenolic compounds. Helichrysum splendidum is able to adapt to and ameliorate soils contaminated with low to high levels of Cu(II) and Pb(II) and has potential for application in phytoextraction and phytostabilization of contaminated soils.
... Some authors detected high accumulations of Zn, moderate amounts of Cr, and low amounts of Pb [78]. Other studies revealed that Cr and Pb can be stored mainly in the roots and show low rates of translocation to their aerial parts, which would determine the low potential of this taxon for phytoremediation purposes [79]. In relation to S. rhombifolia, this medicinal plant showed medium tolerance to Cd and a low accumulation capacity for this metal [80]. ...
The study evaluates pollution by Pb, Zn, and Cr, and a possible sustainable solution through phytoremediation technologies, in the surroundings of Haina, a very polluted area of the Dominican Republic. Soils and plants were analyzed at 11 sampling points. After sample processing, the elemental composition was analyzed by ICP-OES. Soil metal concentrations, contaminating factors, pollution load indexes, and the Nemerow pollution index were assessed. Soil metal concentrations showed Pb > Zn > Cr, resulting in very strong Pb pollution and medium-impact Zn pollution, with an anthropogenic origin in some sites. This means that some agricultural and residential restrictions must be applied. Accumulation levels in plant tissues, bioaccumulation factors in roots and shoots, and translocation factors were determined for Acalypha alopecuroidea, Achyranthes aspera, Amaranthus dubius, Bidenspilosa, Heliotropium angiospermum, Parthenium hysterophorus, and Sida rhombifolia. The vast majority of the plants showed very low levels of the potentially toxic elements studied, although it may be advisable to take precautions before consumption as they are all considered edible, fodder, and/or medicinal plants. Despite their low rate of bioaccumulation, most of the plants studied could be suitable for the application of phytoremediation of Zn in the field, although further studies are needed to assess their potential for this.
... This mechanism minimizes the health risk and human exposure from the metals and metalloid in its leaves, which are being used for medicinal purposes. Even if it is an invasive weed, Alternanthera sessilis may be considered viable for phytoremediation since amaranths exhibit fast growth with high biomass and may grow even in hot weather conditions (Mellem et al. 2009). ...
In unregulated mining and processing for Cu and Au, large amounts of heavy metals and metalloids are generated as tails. These wasted by-products could actually pose serious environmental problems. The objective of this study was to assess the potential ability of Alternanthera sessilis and Aster philippinensis thriving abundantly in a small-scale mine processing site at Kias, Benguet, for possible Cu, Pb, Zn, and As uptake. It also aimed to determine the cellular localization of the contaminants within the plant biomass. Alternanthera sessilis and Aster philippinensis exhibited low bioaccumulation factor (BF) and translocation factor (TF) values for Cu, Pb, Zn, and As. The BF and TF values could suggest possible exclusion mechanisms of the plants in avoiding phytotoxicity. SEM-EDX analysis of the Alternanthera sessilis roots indicated higher weight % of Cu, Pb, and As in the epidermis, and Zn in the cortex. On the other hand, Aster philippinensis roots showed high weight % of Zn and As in the epidermis and Cu and Pb in the cortex. The localization of the contaminants in the root epidermal and cortical cells signifies restriction of their mobility to the xylem, preventing migration to the shoot system. The findings of this study suggest that Alternanthera sessilis and Aster philippinensis are considered potential phytostabilizers capable of immobilizing contaminant toxicity in the soil and in the rhizosphere.
... Based on the results of the study, Bajo starfruit plant growing on fertilized or unfertilized soils has high Ni uptake with TF values of more than 1 ( Figure 5). According to Mellem et al. (2009), if the TF value is more than 1, translocation occurs more in the shoot. The high TF value indicates that the amount of metal translocated to shoot is also high. ...
Bajo starfruit is a wild plant that commonly grows in nickel mining areas and it is known to have the ability to take up Ni metal from the soil, even though its Ni uptake ability is still relatively low. The objective of this study was to explore the effect of the application of citric acid and NPK fertilizer on the ability of Bajo starfruit plant in phytoextraction of Ni from post nickel mining land. Citric acid as a ligand is expected to enhance the availability of Ni in the soil so that Ni uptake by plants increases, while NPK fertilizer is expected to enhance crop biomass production. The treatments tested were combinations of four doses of citric acid (0, 1, 2 and 3 g of citric acid/kg of soil) with two doses of NPK fertilizer (0, and 1.33 g/kg of soil). Eight treatments were arranged in a factorial randomized block design with four replications. The results showed that the application of NPK fertilizer without citric acid increased the number of leaves and dry weight of plants. After the growth of Bajo starfruit for 25 weeks, the application of 3 g citric acid/kg of soil without application of NPK fertilizer reduced the total soil Ni from 8926 ppm to 2400 ppm i.e.73.11%. Application of 2 g citric acid/kg of soil and 1.33 g NPK fertilizer/kg of soil resulted in Ni uptake by 118.18 mg/plant or increased by 38.61% compared to control. Application of 2 g citric acid/kg of soil without application of NPK fertilizer increased the BCF value of Bajo starfruit for nickel from 0.032 (control) to 0.035. However, treatments without the application of citric acid and fertilizer resulted in a higher TF value (13.9).
... Uptake of elements by plants = dry weight of plants x% elements in plants. (Mellem et al., 2009). The effect of CFA application on heavy metal (Zn, Cu, Cd, and Pb) uptake, and crop yields were statistically tested by one-way analysis of variance (one-way ANOVA, followed by the least significant difference (LSD) test at p = 0.05. ...
Considering the content of various elements in coal fly ash (CFA), it has the potential to be used as an additional source of nutrients in the soil. However, the use of CFA for agriculture is still debated because CFA contains several metal elements. The purpose of this study was to study the CFA phytotoxicity to seed germination and metal uptake by plants on acid soil. The first experiment was the study of the effect of extracts of various CFA and soil mixtures (5% - 45% CFA) on the germination of mustard seeds. The second study was a CFA phytotoxicity test for plant growth and metal uptake by the mustard plant. Results of the first experiment showed that the application of CFA had no significant effect on mustard seed germination, but had a significant effect on radicle length. CFA application increased the uptake of Pb and Cu by plant along with the increase in the proportion of CFA in the CFA + soil mixture. The contents of Cu and Pb in the mustard plant due to CFA application up to 30% were still below the threshold levels of Cu (36 ppm) and Pb (2 ppm).
... Metals that are accumulated by plants and largely stored in the roots of plants are indicated by TrF values <1. The greater values of TrF (> 1) indicating translocation to the aerial part of the plant (Mellem et al. 2009). ...
Lead (Pb) is a rapidly increasing heavy metal due to different human activities. It is highly toxic to plants, and its toxicity can impair various morphological, physiological and biochemical functions in plants. In the present study, an experiment was designed to investigate the response mechanisms to counteract Pb in the seedlings of Jatropha curcas. For this purpose, Pb accumulation, metabolite contents, antioxidant activity and accumulation of antioxidants such as phenolics and flavonoids were evaluated. The transcription levels of two genes, metallothioneins (JcMT2a) and phenylalanine ammonia-lyase (JcPAL), involved in the metal detoxification mechanism were also analyzed. The seedlings of J. curcas were hydroponically treated with different doses of Pb (0, 0.5, 5, 10, 20 and 40 mg/L). With increasing Pb dose in the nutrient solution, its accumulation was in the following pattern: roots> stems> leaves. The seedlings showed higher tolerance index (TI) in the highest Pb concentration. The dry weights of roots, stems and leaves, and the total content of proteins were significantly decreased with increasing Pb concentration. However, the photosynthetic pigments, total phenolic and flavonoid compounds were increased in response to elevated Pb concentrations. This was associated with increasing of total antioxidant capacity and radical scavenging activity. Relative transcription of JcMT2a and JcPAL showed distinct pattern in roots and leaves. Integral mechanism for Pb stress tolerance was likely accomplished by activation of antioxidant defense system which was evidenced by up regulation of JcPAL. Our study provides biochemical and genetic basis of Pb-induced defense mechanisms for metal detoxification in J. curcas.
... The translocation factor refers to the ratio of metal concentration in selected aboveground plant organs (C aboveground plant organ ) and metal concentration in roots (C roots ) (Cui et al. 2007;Mellem et al. 2009;Malik et al. 2010): ...
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.
Arbuscular mycorrhizal fungi (AMF) were inoculated into the root system of edible tomato plants to investigate their effect on the uptake and distribution of strontium radionuclide in the tissues of plants grown under laboratory conditions. The experiments were carried out in a sterile mixture of topsoil and sand, where in one series of experiments contaminated soil with 85Sr was used. Seeds were inoculated with a mixture of AMF at sowing, the second, control series was without application of AMF. Determination of radioactivity in soil and in different parts of tomato plants was carried out by gamma-spectrometric measurement. The obtained results and statistical analysis indicated a significant association between AMF inoculation of plants and the change in the distribution of 85Sr. The presence of AMF reduced the translocation of 85Sr from the root system to the aerial parts of tomato plants.
Euphorbia hirta is used traditionally for medicinal purposes. A vast stretch of land in West Bengal is arsenic affected, where agricultural activities present the hazard of arsenic entering the food chain putting the entire community at health risk. The present work tried to study if these areas could be safely utilized to grow this medicinal plant. In this study, the medicinal plant Euphorbia hirta and a known hyperaccumulator Brassica juncea were exposed to a high level of arsenic, and after a certain span of time, arsenic translocation in both the plants was checked. The data revealed that Euphorbia hirta is not a hyperaccumulator and does not translocate high levels of arsenic to the aerial parts of the plant as compared to Brassica juncea. It was also found that the biochemical and genetic effects of arsenic stress were enhanced significantly more in Brassica juncea than in Euphorbia hirta. Thus, the present study points to the growth potential of the common medicinal weed Euphorbia hirta in the arsenic-affected areas without being a cause of human health concern.
Purpose
HDS sediment is a type of solid waste produced when the high-concentration mud method (HDS) is adopted to treat acid wastewater from copper mines. It can rationally utilize sediment resources by using phytoremediation.
Methods
To reveal the effect of different phytoremediation on the heavy metal, enrichment capacity and microbial diversity of the HDS sediments of copper mines, in this experiment, the HDS sediments of a copper mine without phytoremediation were selected as the control group, while the sediments of black locust (Robinia pseudoacacia), slash pine (Pinus elliottii Engelmann) and Chinese white poplar (Populus tomentosa Carr.) were used as test groups to analyze the physical and chemical properties, heavy metal pollution and bioaccumulation capacity of HDS sediments under three phytoremediation.
Results
The results show that different phytoremediation can reduce the sediment's conductivity and adjust the sediment's pH value to the range suitable for plant growth. The BCFShoot and BTF values of Chinese white poplar to Cd and Zn and slash pine to Pb were both greater than 1.
Conclusions
As discovered from the bioconcentration coefficient and biotransport coefficient results, Chinese white poplar is an enriched plant of Cd and Zn, while slash pine is a plant full of Pb.
Phytoremediation is also called “botanical bioremediation” and is becoming a promising area of research, which has a tremendous effect on the decontamination of polluted soils, air, and water. Conventional remediation methods of heavy metal contaminated soils are expensive and environmentally destructive that leads to the discovery of eco-friendly and cost-effective alternate technologies. Metals with an atomic weight greater than 20, metallic density higher than 5 g cm−3, and a specific gravity greater than four are considered heavy metals. Some heavy metals are essential for plant growth (Fe, Mn, Zn, Cu, Mg, Mo, and Ni), and some metals are with unknown biological functions (Cd, Cr, Pb, Co, Ag, Se, Hg). The metal fraction in the environment is highly variable, and they are introduced into the atmosphere by both natural and anthropogenic sources. Metal hyperaccumulating plants have gained increased attention because of their potential to accumulate heavy metals, thereby decontamination of metal-polluted soil. This chapter provides information about the phytoremediation potential of various weed plants belonging to the families Amaranthaceae and Euphorbiaceae on heavy metal contaminated soil. Weeds are suitable for this purpose because of their inherent resistant capability and their non-suitability for fodder purposes. Species of Amaranthus, Alternanthera, Celosia, Achyranthes, etc. from the family Amaranthaceae and Acalypha, Phyllanthus, Euphorbia, Jatropha, etc., from the family Euphorbiaceae are proven hyperaccumulator weed plants that can be used as effective phytotemediator in heavy metal contaminated soil.
Sludge landscaping after compost stabilization is a popular recycling process; however, until trace elements (TEs) are extracted by plants and reduced to safe concentrations, they present a potential exposure risk. Three garden plants, Liriope platyphylla Wang et Tang (L. platyphylla), Iris tectorum Maxim (I. tectorum), and Photinia x fraseri Dress (P. x fraseri), were selected for field experiments, and their ability to phytoremediate TEs and the promotion effect of citric acid (CA) were studied over 3 months of observation. Among the three kinds of plants, L. platyphylla had the highest biomass per unit soil area, and the CA treatment further increased the biomass of this plant per unit soil area as well as the uptake of TEs. When treated with 3 mmol kg⁻¹ CA, L. platyphylla showed increases in the bioconcentration factors of Cu, Zn, Pb, and Cd by 24%, 63%, 27%, and 123%, respectively. Because of the large biomass and high concentrations of TEs, L. platyphylla had high phytoremediation indexes for Zn, Cu, Pb, Ni, and Cd, which reached 18.5, 3.7, 3.2, 2.2, and 0.4 mg m⁻², respectively, and were further improved by 60%–187% by the CA treatment. These advantages indicate the potential usefulness of L. platyphylla for phytoremediation. The results provide basic data and technical support for the use of sludge-based compost and phytoremediation by garden plants.
The aim of our study is to determine the hyperaccumulatory properties by examining the heavy metal accumulation (Co, Ni, Fe) in endemic Anchusa leptophlla subsp. tomentosa, Alyssum pateri subsp. pateri, Glaucium acutidentatum and non endemic Erysimum uncinatifolium species collected from a copper mining area in Elazığ Maden district. All species collected are hyperaccumulator according to their Bioconcentration Factor (BCF) values of Co element. According to NiBCF and FeBCF values, A. leptophlla and E. uncinatifolium species were found to be hyperacumulators. According to Transfer Factor (TF) value, it is determined that Co element can be transported upper organs in A. leptophlla, A. pateri species, whereas Ni and Fe elements in A. leptophlla, A. pateri, E. uncinatifolium species. Among the species examined, the CoEF values for A. leptophlla and NiEF values (EF>1) in all species are found to be higher than 1 according to the Enrichment Factor (EF). It can be said that the Ni accumulation capacities of all species are higher. In the study, soils samples taken from sampling area according to the Geo-accumulation index (Igeo) were found to be moderately contaminated in by Co and not so polluted by Fe.
The latest developments in photovoltaic studies focus on the best use of the solar spectrum through Luminescent Solar Concentrators (LSC). Due to their structural characteristics, LSC panels allow considerable energy savings. This significant saving can also be of great interest in the remediation of contaminated sites, which nowadays requires green interventions characterized by high environmental sustainability. This study reported the evaluation of LSC panels in phytoremediation feasibility tests. Three plant species were used at a microcosm scale on soil contaminated by arsenic and lead. The experiments were conducted by comparing plants grown under LSC panels doped with Lumogen Red F305 (BASF) with plants grown under polycarbonate panels used for greenhouse construction. The results showed a higher production of biomass by the plants grown under the LSC panels. The uptake of the two contaminants by plants was the same in both the growing conditions, thus resulting in an increased total accumulation (defined as metal concentration times produced biomass) in plants grown under LSC panels, indicating an overall higher phytoextraction efficiency. This seems to confirm the potential that LSCs have to be building-integrated on greenhouse roofs, canopies, and shelters to produce electricity while increasing plants productivity, thus reducing environmental pollution, and increasing sustainability.
Landfill leachate is characterised by high chemical and biological oxygen demand and generally consists of undesirable substances such as organic and inorganic contaminants. Landfill leachate may differ depending on the content and age of landfill contents, the degradation procedure, climate and hydrological conditions. We aimed to explain the characteristics of landfill leachate and define the practicality of using different techniques for treating landfill leachate. Different treatments comprising biological methods (e.g. bioreactors, bioremediation and phytoremediation) and physicochemical approaches (e.g. advanced oxidation processes, adsorption, coagulation/flocculation and membrane filtration) were investigated in this study. Membrane bioreactors and integrated biological techniques, including integrated anaerobic ammonium oxidation and nitrification/denitrification processes, have demonstrated high performance in ammonia and nitrogen elimination, with a removal effectiveness of more than 90%. Moreover, improved elimination efficiency for suspended solids and turbidity has been achieved by coagulation/flocculation techniques. In addition, improved elimination of metals can be attained by combining different treatment techniques, with a removal effectiveness of 40–100%. Furthermore, combined treatment techniques for treating landfill leachate, owing to its high chemical oxygen demand and concentrations of ammonia and low biodegradability, have been reported with good performance. However, further study is necessary to enhance treatment methods to achieve maximum removal efficiency. HIGHLIGHTS
Membrane bioreactors and integrated biological techniques could remove up to 100% of ammonia.;
Enhanced elimination of metals can be gained by combining different treatment methods.;
Better elimination efficiency for suspended solids has been achieved by coagulation/flocculation.;
In Chile, 85% of tailings impoundments are inactive or abandoned and many of them do not have a program of treatment or afforestation. The phytoremediation of tailings with Oxalis gigantea, Cistanthe grandiflora, Puya berteroniana and Solidago chilensis have been tested in order to find plants with ornamental value and low water requirements, which enable reductions in molybdenum (Mo), copper (Cu) or lead (Pb) concentrations creating an environmentally friendly surrounding. Ex-situ phytoremediation experiments were carried out for seven months and Mo, Cu and Pb were measured at the beginning and at the end of the growth period. The capacity of these species to phyto-remedy was evaluated using the bioconcentration and translocation factors, along with assessing removal efficiency. Solidago chilensis showed the ability to phytoextract Mo while Puya berteroniana showed potential for Cu and Mo stabilization. The highest removal efficiencies were obtained for Mo, followed by Cu and Pb. The maximum values of removal efficiency for Mo, Cu and Pb were 28.7% with Solidago chilensis, 15.6% with Puya berteroniana and 8.8% with Cistanthe grandiflora, respectively. Therefore, the most noticeable results were obtained with Solidago chilensis for phytoextraction of Mo.
Abstract
Background and Objectives: Soil contamination is one of the most important pollutants in the environment. Lead (Pb) is one of the heavy metals and important pollutant in arid ecosystem. The use of plants to remove contaminated soil or Phytoremediation is an economical method. Todays due to increasing the pullution of soil sources and resultant problems, identification the resistant plant species against soil pollution is essential. Effeciency of Vetiver and Brassica to Pb uptake has not studied and compared, therefore, this study was carried out in order to compare the Phytoremediation capacity of Pb by two plants i.e. Vetiveria zizanioides and Brassica oleraceae, and to indentify the better specie for this purpose.
Materials and Methods: A completely randomized design with factorial arrangement in greenhouse conditions was carried out. Treatments included two types of plants (Vetiveria zizanioides and Brassica oleraceae) and three rates of Pb contamination in soil (50, 250 and 500 mg / kg prepared from lead nitrate) in three replicates. After measuring the amount of Pb in soil by DTPA, the concentration of Pb in root and shoot of plants, Translocation factor (translocation from roots to shoots) and Bio-accumulation factor (translocation from soil to roots) were measured, too. Data analysis was performed using JMP software and comparison of means by LSD method.
Results: The results of analysis of variance showed that the effect of plant type, soil contamination rates and their interaction on accumulation content of lead in root and soil were Significant at P<0.01, while the effect of soil contamination rate on the shoots of plant was Significant at P<0.05. The highest accumulation contents of lead in roots and shoots were found in Vetiver plant containing 250 mg / kg of soil pollution rate treatment. Also, the highest amount of Pb accumulation in soil was related to Brassica containing 500 mg/kg of soil treatment. Vetiver in root and shoots accumulated Pb 3.5 and 2.1 times more than Brassica, respectively. In addition, the accumulation content of Pb in the roots of Vetiver was 4 times higher than its shoots, while the concentration of Pb in roots of Brassica was 1.5 times greater than its shoots. Translocation factor in both plant was less than 1, while bio-accumulation factor of Vetiver was greater than that of Brassica in all Pollution rates.
Conclusion: Despite the ability of both plants to accumulate lead in their roots and shoots, Vetiver had the better performance in lead uptake from soil and reduced lead amount in soil, so its application is recommended for Phytoremediation purposes.
Contamination through heavy metals/metalloids as well as other pollutants is a major concern to the environment. There is a gradual increase in the concentration of these toxic metal/metalloids and pollutants in the soil because of human as well as natural actions. To remove these contaminants from soil, phytoremediation is a very efficient, cheap and environmental friendly approach. Recently, for phytoremediation of these metals/metalloids contaminated soil, a novel method of phytoextraction and phytomining with hyperaccumulator plants is gaining popularity. Of these hyperaccumulator plant species, Brassicaceae has shown potential for removing these pollutants completely and permanently. Members of this family like T. caerulescens, A. murale, A. halleri, B. napus, B. nigra, R. sativus are very efficient phytoremediators. Indian mustard (B. juncea), belonging to this family is known to have a very high capacity for phytoremediation.
The leachate efluen of Semarang landfill is directly flew to the upper course of Kreo river is a fact that make Kreo river is possibly contaminated by heavy metal. Many banana trees are planted around the contaminated0soil. This study was conducted to determine Cr toxicity on banana trees that grow on contaminated soil and to determine public health risks that is caused by leachate of Semarang landfill. The measurement of bioaccumulation factor as the basic data for environmental safety and as the evaluation of wastewater processing is conducted through Cr level measurement. The research shows 1) Cr concentration on WWTP Jatibarang Semarang landfill’s efluen leachate in the rainy season exceeds the environmental safety limit. 2) Cr concentration in the water before and the after of efluen leachate contamination is under the standard. 3) Cr contamination in the soil around Jatibarang landfill’s efluen leachate contamination area exceeds its limit. 4) The bioconcentration factor shows the banana trees can accumulate Cr from soil to the tree. 5) Most of Cr accumulation in the banana trees is translocated to the air and to the root of the tree. 6) The banana plants such as root, stem and pseudostem from the Cr contaminated soil is safe for consumption.
Phytoremediation efficiency depends on the ability of plants to accumulate, translocate and resist high levels of metals without symptoms of toxicity. This study was conducted to evaluate the potential of grain amaranth for remediation of soils contaminated with Cd. Three grain amaranth varieties, “Pribina” (A. cruentus), “Zobor” (A. hypochondriacus x A. hybridus) and Plainsman (A. hypochondriacus x A. hybridus) were tested under different level of Cd (0, 5, 10 and 15 mg/L) in a hydroponic experimental treatment. All could be classified as Cd excluders or Cd-hypertolerant varieties able to grow and accumulate significant amounts of Cd from the hydroponic solution, preferentially in the roots. Under the highest level of Cd exposure, qRT-PCR expression analysis of five stress-related genes was examined in above- and below-ground biomass. The results show that the Cd concentration significantly increased the mRNA level of chitinase 5 (Chit 5) in amaranth roots as the primary site of metal stress. The involvement of phytochelatin synthase (PCS1) in Cd detoxification is suggested. Based on our findings, we can conclude that variety “Pribina” is the most Cd-tolerant among three tested and can be expected to be used in the phytomanagement of Cd loaded soils as an effective phytostabiliser.
Some heavy metals have bio-importance as trace elements but, the biotoxic effects of many of them in human biochemistry are of great concern. Hence, there is the need for proper understanding of the conditions, such as the concentrations and oxidation states, which make them harmful, and how biotoxicity occurs. It is also important to know their sources, leaching processes, chemical conversions and their modes of deposition to pollute the environment, which essentially supports lives. Literature sources point to the fact that these metals are released into the environment by both natural and anthropogenic sources, especially mining and industrial activities, and automobile exhausts (for lead). They leach into underground waters, moving along water pathways and eventually depositing in the aquifer, or are washed away by run-off into surface waters thereby resulting in water and subsequently soil pollution. Poisoning and toxicity in animals occur frequently through exchange and co-ordination mechanisms. When ingested, they combine with the body's biomolecules, like proteins and enzymes to form stable biotoxic compounds, thereby mutilating their structures and hindering them from the bioreactions of their functions. This paper reviews certain heavy metals and their biotoxic effects on man and the mechanisms of their biochemical activities.
This review presents the status of phytoremediation technologies with particular emphasis on phytoextraction of soil heavy metal contamination. Unlike organic compounds, metals cannot be degraded, and cleanup usually requires their removal. Most of the conventional remedial technologies are expensive and inhibit the soil fertility; this subsequently causes negative impacts on the ecosystem. Phytoremediation is a cost effective, environmental friendly, aesthetically pleasing approach most suitable for developing countries. Despite this potential, phytoremediation is yet to become a commercially available technology in India. This paper reports about the mobility, bioavaliability and plant response to presence of soil heavy metals. It classifies the plants according to phytoextraction mechanism and discusses the pathway of metal in plants. Various techniques to enhance phytoextraction and utilization of by-products have been elaborated. Since lot of biomass is produced during this process, it needs proper disposal and management. It also gives an insight into the work done by authors, which focuses on high biomass extractor plants. High biomas weeds were selected to restrict the passage of contaminants into the food chain by selecting non-edible, disease resistant and tolerant plants, which can provide renewable energy. Thus making phytoextraction more viable for present utilization. Keywords. heavy metals, phytoextraction, hyperaccumulator, indicator, excluder species
To identify populations with the ability to accumulate heavy metals, approximately 300 accessions pertaining to 30 plant species were grown for 4 wk in a hydroponic media that approximated the nutrient and heavy metal composition of a soil contaminated with moderate levels of cadmium (Cd), copper (Cur, and zinc (Zn). The results indicated that several Brassica spp. exhibited moderately enhanced Zn and Cd accumulation. Selected accessions of Brassica juncea (L.) Czern, B. napus L., and B. rapa L. were then grown in pots with heavy metal-contaminated soil to compare the Zn and Cd phytoextraction by these species to that of Thlaspi caerulescens J. & C. Presl, a known Zn and Cd hyperaccumulator, and two grass species, Agrostis capillaris L. and Festuca rubra L. The three Brassica spp. were the most effective in removing Zn from the contaminated soil, primarily because they produced more than 10 times the shoot biomass produced by T. caerulescens. When the soil was amended with Gro-Power, a commercial soil amendment that improves soil structure and fertility, removal of Zn by plant shoots doubled to more than 30 000 mg Zn pot-1 (4.5 kg). The results suggest that for phytoremediation of metal-polluted soils to be successful, a strategy should be considered that combines rapid screening of plant species possessing the ability to tolerate and accumulate heavy metals with agronomic practices that enhance shoot biomass production and/or increase metal bioavailability in the rhizosphere.
Wastewater from a sewage treatment works is channelled through a series of inter-connected settling ponds into a stream. Furthermore, leachates from a domestic and industrial landfill site are disposed into the first pond. From the variety of plants growing in the ponds, A. sessilis, P. stratiotes, R. steudelii and T. capensis were investigated for their ability to uptake chromium, lead and nickel (these metals are toxic to humans while nickel is also involved in plant growth). The levels of the metals in the water, plants and sludge were determined using an inductively coupled plasma-mass spectrometer (ICP-MS). For the plants, the amounts of the metals in roots, stems and leaves were also measured. In general it was found that the plants accumulated up to 15% of the level of metals in the water and that accumulation depends on the plant species as well as on the organ of the plant. The concentrations of metals in the water in the last pond were found to be well within the limits set by the South African National Water Act of 1998 for discharge of water into rivers. Furthermore, the results of this study, which involved a real system, were compared with those from model studies where conditions of the system could be controlled by the investigator.
Phytoextraction has shown great potential as an alternative technique for the remediation of metal contaminated soils. The objective of this study was to investigate cadmium (Cd) phytoextraction ability of high biomass producing weeds in comparison to indicator plant species. The pot study conducted with 10 to 200 mg Cd kg−1 soil indicated that Ipomoea carnea was more effective in removing Cd from soil than Brassica juncea. Among the five species, B. juncea accumulated maximum Cd, but I. carnea followed by Dhatura innoxia and Phragmytes karka were the most suitable species for phytoextraction of cadmium from soil, if the whole plant or above ground biomass is harvested. In the relatively short time of this experiment, I. carnea produced more than 5 times more biomass in comparison to B. juncea. There were significant differences (p < 0.05) between the shoot length and shoot mass of control and treated plants.
A small number of wild plants that grow on metal-contaminated soil accumulate large amounts of heavy metals in their roots and shoots. This property may be exploited for soil reclamation if an easily cultivated, high biomass crop plant able to accumulate heavy metals is identified. Therefore, the ability of various crop plants to accumulate Pb in shoots and roots was compared. While all crop Brassicas tested accumulated Pb, some cultivars of Brassica juncea (L.) Czern, showed a strong ability to accumulate Pb in roots and to transport Pb to the shoots (108.3 mg of Pb/g DW in the roots and 34.5 mg of Pb/g DW in the shoots). B. juncea was also able to concentrate Cr6+, Cd, Ni, Zn, and Cu in the shoots 58-, 52-, 31-, 17-, and 7-fold, respectively, from a substrate containing sulfates and phosphates as fertilizers. The high metal accumulation by some cultivars of B. juncea suggests that these plants may be used to clean up toxic metal-contaminated sites in a process termed phytoextraction.
The importance of biodiversity (below and above ground) is increasingly considered for the cleanup of the metal contaminated and polluted ecosystems. This subject is emerging as a cutting edge area of research gaining commercial significance in the contemporary field of environmental biotechnology. Several microbes, including mycorrhizal and non-mycorrhizal fungi, agricultural and vegetable crops, ornamentals, and wild metal hyperaccumulating plants are being tested both in lab and field conditions for decontaminating the metalliferous substrates in the environment. As on todate about 400 plants that hyperaccumulate metals are reported. The families dominating these members are Asteraceae, Brassicaceae, Caryophyllaceae, Cyperaceae, Cunouniaceae, Fabaceae, Flacourtiaceae, Lamiaceae, Poaceae, Violaceae, and Euphobiaceae. Brassicaceae had the largest number of taxa viz. 11 genera and 87 species. Different genera of Brassicaceae are known to accumulate metals. Ni hyperaccumulation is reported in 7 genera and 72 species and Zn in 3 genera and 20 species. Thlaspi species are known to hyperaccumulate more than one metal i.e. T. caerulescence = Cd, Ni. Pb, and Zn; T. goesingense = Ni and Zn and T. ochroleucum = Ni and Zn and T. rotundifolium = Ni, Pb and Zn. Plants that hyperaccumulate metals have tremendous potential for application in remediation of metals in the environment. Significant progress in phytoremediation has been made with metals and radionuclides. This process involves rising of plants hydroponically and transplanting them into metal-polluted waters where plants absorb and concentrate the metals in their roots and shoots. As they become saturated with the metal contaminants, roots or whole plants are harvested for disposal. Most researchers believe that plants for phytoremediation should accumulate metals only in the roots. Several aquatic species have the ability to remove heavy metals from water, viz., water hyacinth ( Eichhornia crassipes (Mart.) Solms); pennywort ( Hydrocotyle umbellata L.) and duckweed ( Lemna minor L.). The roots of Indian mustard are effective in the removal of Cd, Cr, Cu, Ni, Pb, and Zn and sunflower removes Pb, U, 137Cs, and 90rate and accumulate metals in their shoots. Genes responsible for metal hyperaccumulation in plant tissues have been identified and cloned. Glutathione and organic acids metabolism plays a key role in metal tolerance in plants. Glutathione is ubiquitous component cells from bacteria to plants and animals. In phytoremediation of metals in the environment, organic acids play a major role in metal tolerance. Organic acids acids form complexes with metals, a process of metal detoxification. Genetic strategies and transgenic plant and microbe production and field trials will fetch phytoremediaition field applications.The importance of biodiversity and biotechnology to remediate potentially toxic metals are discussed in this paper. Brassicaceae amenable to biotechnological improvement and phytoremediation hype are highlighted.
Indian mustard (Brassica juncea L.), a high biomass crop plant, accumulated substantial amounts of cadmium, with bioaccumulation coefficients (concentration of Cd in dry plant tissue/concentration in solution) of up to 1100 in shoots and 6700 in roots at nonphytotoxic concentrations of Cd (0.1 [mu]g/mL) in solution. This was associated with a rapid accumulation of phytochelatins in the root, where the majority of the Cd was coordinated with sulfur ligands, probably as a Cd-S4 complex, as demonstrated by x-ray absorption spectroscopy. In contrast, Cd moving in the xylem sap was coordinated predominantly with oxygen or nitrogen ligands. Cd concentrations in the xylem sap and the rate of Cd accumulation in the leaves displayed similar saturation kinetics, suggesting that the process of Cd transport from solution through the root and into the xylem is mediated by a saturable transport system(s). However, Cd translocation to the shoot appeared to be driven by transpiration, since ABA dramatically reduced Cd accumulation in leaves. Within leaves, Cd was preferentially accumulated in trichomes on the leaf surface, and this may be a possible detoxification mechanism.
Hydroponic and soil cultivations of Thelypteris palustris, the common marsh fern, were used to investigate its potential for use in phytoremediation of arsenic (As) contaminated water or soil. ICP-MS analyses indicate that both roots and fronds accumulated arsenic in levels up to 100 times the concentration of treatment solutions of 250 microg/L and 500 mug/L arsenic, but values varied widely and there was no significant difference in concentrations in fronds between the control (no arsenic) and treatments. Plants exposed to 500 microg/L exhibited necrosis in their fronds, suggesting that Thelypteris palustris is not a good candidate for phyotoremediation of arsenic-contaminated sites.
The metal content in several TCM drugs was determined by ICP-MS. The efficiencies of different sample digestion methods were compared. Since one of the products studied is known to contain arsenic sulfides as a main ingredient, a solvent fractionation scheme was developed and applied to speciate As in the product. The metal content in the same TCM drug produced by different manufacturers was compared. The concentration of some metals such as Pb and Cd differs widely with different manufacturers, suggesting that their origin is primarily from external contamination. The high sensitivity and precision of the ICP-MS technique offers considerable advantages over conventional ICP-OES techniques for the analysis of complex samples such as TCM materials. Standardized analytic protocols based on ICP-MS are being developed fur the determination and characterization of metals and trace elements in TCM materials for product quality assessment.
The leaves of Elaeagnus angustifolia L. (Elaeagnaceae) were tested as a possible biomonitor of heavy metal pollution in Kayseri. Concentration of Pb, Cd and Zn were determined in unwashed and washed leaves and soils. Differences between the unwashed and washed samples varied according to the metal pollutant levels. Significant correlations were obtained between the heavy metal concentrations in surface soil and washed leaf samples. E. angustifolia was found to be a useful biomonitor of the heavy metals investigated.
Digestion of biological materials is very important for trace element determinations. Although the microwave technique is mostly used, there are cases where open wet digestion is needed. This study examined the optimum conditions for the minimum loss of trace elements duringt he wet digestion of a sample. The effect of acid composition and digestion time for about 21 ions was investigated. The trace element concentrations were determined by differential pulse polarography. For the digestion procedure, a HClO4-HNO 3 mixture was used for the first step and, after its evaporation (60 min), HCl was added as the second step, since in some cases it was necessary. The recoveries were high for ions like Zn, Cu, Ti(IV), Cd, Fe, Mn(II), Co(II), V(III) and Mo(VI) after digestion (60 min) with the HNO3-HClO 4 mixture and the addition of HCl had no effect. However, although care was taken to minimize losses by usinga long-necked (30 cm) flask, low recoveries were obtained for Pb, Se(IV), As(III), Cr(III) and Cr(VI) when HCl was used after HClO4-HNO3 digestion. Since Se(IV), As(III), Cr(III), Sn(II) and Sb(III) were oxidized by the acid mixture this fact has to be considered for some procedures and they have to be reduced before their determination. It was found that when HNO3 was used alone or in an acid mixture for digestion, the recovery of Ni was only 40%. However, with the use of HClO4 or H2SO4, the recovery was very high.
Digestion of biological materials is very important for trace element determinations. Although the microwave technique is mostly used, there are cases where open wet digestion is needed. This study examined the optimum conditions for the minimum loss of trace elements during the wet digestion of a sample. The effect of acid composition and digestion time for about 21 ions was investigated. The trace element concentrations were determined by differential pulse polarography. For the digestion procedure, a HClO4-HNO3 mixture was used for the first step and, after its evaporation (60 min), HCl was added as the second step, since in some cases it was necessary. The recoveries were high for ions like Zn, Cu, Ti(IV), Cd, Fe, Mn(II), Co(II), V(III) and Mo(VI) after digestion (60 min) with the HNO3-HClO4 mixture and the addition of HCl had no effect. However, although care was taken to minimize losses by using a long-necked (30 cm) flask, low recoveries were obtained for Pb, Se(IV), As(III), Cr(III) and Cr(VI) when HCl was used after HClO4-HNO3 digestion. Since Se(IV), As(III), Cr(III), Sn(II) and Sb(III) were oxidized by the acid mixture this fact has to be considered for some procedures and they have to be reduced before their determination. It was found that when HNO3 was used alone or in an acid mixture for digestion, the recovery of Ni was only 40%. However, with the use of HClO4 or H2SO4, the recovery was very high.
(Microwave digestion of plant material for trace element determination.) A digestion method utilizing a mixture of nitric acid, hydrofluoric acid and hydrogen peroxide in closed vessels with a microwave system was developed for the determination of trace elements in plant materials and was tested on NIST standard reference materials [Citrus Leaves (SRM 1572) and Pine Needles (SRM 1575)] for Al, As, Ba, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Rb, Sr and Zn. Analyses were done by d.c. plasma atomic emission spectrometry. The results showed high reproducibility and good agreement with the certified values. Rapid ashing and dissolution of plant material, reduced sources of contamination and the simplicity of the system make the microwave digestion system suitable for routine laboratory application.ZusammenfassungFür die Bestimmung von Spurenelementen in Pflanzenmaterial wird ein Mikrowellenaufschlussverfahren im geschlossenen System unter Einsatz eines Säuregemisches aus Salpeter- und Flusssäure und Zusatz von Wasserstoff- peroxid vorgestellt. Die Aufschlussmethode wird anhand der Elemente Al, As, Ba, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Rb, Sr und Zn mit den Standardreferenzmaterialien von NIST, citrus leaves (SRM 1572) und pine needles (SRM 1575), getestet. Die mit der Plasmaemissionsspektrometrie ermittelten Elementkonzentrationen werden mit den zertifizierten Gehalten verglichen und zeigen sehr gute Übereinstimmungen wie auch hohe Reproduzierbarkeiten. Die kurzen Aufschlusszeiten, die reduzierten Kontaminationsgefahren und die leichte Handhabung lassen das Verfahren als geeignet für den Routinebetrieb im Labor erscheinen.
Phytoremediation is emerging as a potential cost-effective solution for the remediation of contaminated soils. Because contaminants such as lead (Pb) have limited bioavailability in the soil, a means of solubilizing the Pb in the soil and facilitating its transport to the shoots of plants is vital to the success of phytoremediation. Indian mustard (Brassica juncea) was used to demonstrate the capability of plants to accumulate high tissue concentrations of Pb when grown in Pb-contaminated soil. Concentrations of 1.5% Pb in the shoots of B. juncea were obtained from soils containing 600 mg of Pb/kg amended with synthetic chelates such as EDTA. The accumulation of Pb in the tissue corresponded to the concentration of Pb in the soil and the concentration of EDTA added to the soil. The accumulation of Cd, Cu, Ni, and Zn from contaminated soil amended with EDTA and other synthetic chelators was also demonstrated. The research indicates that the accumulation of metal in the shoots of B. juncea can be enhanced through the application of synthetic chelates to the soil, facilitating high biomass accumulation as well as metal uptake.
IntroductionCobalt and CopperNickelZincConclusion
The changing levels of lead (Pb) in the soil and vegetationalong two National Highways near Lucknow, India, wereinvestigated. The pattern of Pb deposition, as reflected bysoil Pb burdens, showed decrease in concentration withincreasing distances from the road margins. At both the sitesPb concentration was above background concentration even atthe soil core depth of 15 cm. Oryza sativa, Colocasiaesculentum, Luffa cylindrica and Cynodon dactylonplants contained a high mean concentration of Pb over theirrespective controls, with more accumulation in the undergroundportions of the plants. Milk samples, collected from cattlethat normally graze on the roadside pasture-lands dominatedby Cynodon dactylon, contained Pb at an elevatedconcentration.
Trivalent chromium (Cr3+) is essential for animal and human health, whereas hexavalent Cr (CrO42−) is a potent carcinogen and extremely toxic to animals and humans. Thus, the accumulated Cr in food plants may represent potential health hazards to animals and humans if the element is accumulated in the hexavalent form or in high concentrations. This study was conducted to determine the extent to which various vegetable crops absorb and accumulate Cr3+ and CrO42− into roots and shoots and to ascertain the different chemical forms of Cr in these tissues. Two greenhouse hydroponic experiments were performed using a recirculating-nutrient culture technique that allowed all plants to be equally supplied with Cr at all times. In the first experiment, 1 mg L−1 Cr was supplied to 11 vegetable plant species as Cr3+ or CrO42−, and the accumulation of Cr in roots and shoots was compared. The crops tested included cabbage (Brassica oleracea L. var. capitata L.), cauliflower (Brassica oleracea L. var. botrytis L.), celery (Apium graveolens L. var. dulce (Mill.) Pers.), chive (Allium schoenoprasum L.), collard (Brassica oleracea L. var. acephala DC.), garden pea (Pisum sativum L.), kale (Brassica oleracea L. var. acephala DC.), lettuce (Lactuca sativa L.), onion (Allium cepa L.), spinach (Spinacia oleracea L.), and strawberry (Fragaria ×
ananassaDuch.). In the second experiment, X-ray absorption spectroscopy (XAS) analysis on Cr in plant tissues was performed in roots and shoots of various vegetable plants treated with CrO42− at either 2 mg Cr L−1 for 7 d or 10 mg Cr L−1 for 2, 4 or 7 d. The crops used in this experiment included beet (Beta vulgaris L. var. crassa (Alef.) J. Helm), broccoli (Brassica oleracea L. var. Italica Plenck), cantaloupe (Cucumis melo L. gp. Cantalupensis), cucumber (Cucumis sativus L.), lettuce, radish (Raphanus sativus L.), spinach, tomato (Lycopersicon lycopersicum (L.) Karsten), and turnip (Brassica rapa L. var. rapifera Bailey). The XAS speciation analysis indicates that CrO42− is converted in the root to Cr3+ by all plants tested. Translocation of both Cr forms from roots to shoots was extremely limited and accumulation of Cr by roots was 100-fold higher than that by shoots, regardless of the Cr species supplied. Highest Cr concentrations were detected in members of the Brassicaceae family such as cauliflower, kale, and cabbage. Based on our observations and previous findings by other researchers, a hypothesis for the differential accumulation and identical translocation patterns of the two Cr ions is proposed.
Experience gained with the remediation of contaminated sites over the last 10 to 15 years has strongly increased the insight into the problem and how it can be tackled. A large number of remediation techniques, most of which focus on clean-up, are now available, and some of them are intensively applied in practice. However, the experiences gained with them show that they are not capable of solving all problems. Furthermore, each case of soil pollution is different and the way to manage it requires, within the limits set by policy and the finances available, a careful weighing of all relevant factors. Increased knowledge about the problem has resulted in potential new techniques, such as extensive in-situ treatment, the use of special treatment walls, phytoremediation and intrinsic natural degradation.
Accurate estimations of the emissions of primary pollutants are crucial for the modeling of photo-oxidants’ concentrations. For a majority of chemistry-transport models (CTMs), these emissions are taken into account near the surface only. They are expressed as surface fluxes and represent surface activities such as traffic, industries or biogenic processes. However, in the vicinity of large cities, commercial aircraft emissions represent a nonnegligible source, located both at the surface and at altitude, including landing and take-off of aircraft within the boundary layer. This is the case of Paris where one national airport (Le Bourget) and two international airports (Roissy-Charles-de-Gaulle and Orly) are located less than away from the city center. This study presents the first-model analysis of the impact of aircraft emissions on photo-oxidant concentrations over the Paris area. Using a three-dimensional aircraft emission inventory, we compare ozone surface concentrations obtained with and without these emissions by running the CTM CHIMERE during the second Intensive Observation Period of the ESQUIF project. The simulated differences enable us to estimate the impact of aircraft traffic emissions on ozone surface concentrations in and around the city. The results showed that the maximum impact, which consists in a fast ozone titration by NO near the airports within the surface layer, occurs during the night. In remote areas and at altitude, adding new emissions enhanced photo-chemistry during the afternoon. In order to estimate the impact of the uncertainty of our inventory, aircraft emitted masses of volatile organic compounds (VOCs) and NOx are perturbed. The results showed that NOx air traffic emissions have a more important impact than VOC emissions, particularly during the night and near the sources. Nevertheless, these variations of air traffic emissions do not change previous conclusions.
Plant-based remediation techniques are showing increasing promise for use in soils contaminated with organic and inorganic pollutants. Two contrasting approaches to remediation are being pursued: pollutant-stabilization and containment, where soil conditions and vegetative cover are manipulated to reduce the environmental hazard; and decontamination, where plants and their associated microflora are used to eliminate the contaminant from the soil.
Phytoremediation uses plants to remove pollutants from the environment. The use of metal-accumulating plants to clean soil and water contaminated with toxic metals is the most rapidly developing component of this environmentally friendly and cost-effective technology. The recent discovery that certain chelating agents greatly facilitate metal uptake by soil-grown plants can make this technology a commercial reality in the near future.
Samples of Pteris vittata L. (brake fern or ladder brake) collected in Genova and in areas outside urban centres, have been analysed for arsenic content in order to assess if hyper accumulating plants are suitable for monitoring purposes. Hyper accumulation ability of the Ligurian fern populations was evaluated by analysing specimens grown with hydroponic media added with As(v). Arsenic concentrations in the range 2-310 microg g(-1) dry weight have been measured in samples collected in different sites along the Ligurian coast. Arsenic concentrations in fern fronds correlate with the estimated arsenic emission in the area, verifying the applicability of P. vittata as an arsenic biomonitor.
Contaminated soils and waters pose a major environmental and human health problem, which may be partially solved by the emerging phytoremediation technology. This cost-effective plant-based approach to remediation takes advantage of the remarkable ability of plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues. Toxic heavy metals and organic pollutants are the major targets for phytoremediation. In recent years, knowledge of the physiological and molecular mechanisms of phytoremediation began to emerge together with biological and engineering strategies designed to optimize and improve phytoremediation. In addition, several field trials confirmed the feasibility of using plants for environmental cleanup. This review concentrates on the most developed subsets of phytoremediation technology and on the biological mechanisms that make phytoremediation work.
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.
The uptake of an element by a plant is primarily dependent on the plant species, its inherent controls, and the soil quality. Amaranthus hybridus (green herbs) and Amaranthus dubius (red herbs) were chosen to investigate their response and ability to accumulate and tolerate varying levels of elements in their roots and shoots. Red herbs and green herbs were grown in soil pots contaminated with three mixtures of Cd(II), Ni(II), Pb(II), and Hg(II). Plants in the control treatment were grown in the absence of the heavy metals mixture. The distribution of Cd, Ni, Pb, and Hg in the plants (in roots, stems, and leaves) was determined in two stages. Stage 1, after 5 weeks of plant growth and stage 2, full grown after 10 weeks of growth. In the red herbs the Cd concentration in the leaves at stage 2 was 150 ppm and was present in higher concentrations than Ni, Hg, and Pb. At the highest contamination level, in the green herbs plant, Hg was present in the highest concentration in the root, i.e., 336 ppm at stage 1, while the level in the leaves was 7.12 ppm. Both the green and red herbs species showed an affinity for Ni and Cd with moderate to high levels detected in the leaves, respectively.
The impact of coal mine dump contaminated soil on the elemental uptake by two edible plants, namely, Amaranthus dubius (red herbs) and Amaranthus hybridus (green herbs), was studied by investigating their response and ability to tolerate and accumulate varying levels of elements in their roots and shoots. The vegetation was grown on varying amounts of contaminated soil, viz. 0%, 5%, 15%, 25% w/w using coal mine dump soil. The soil was analyzed for soil pH, cation exchange capacity (CEC), soil organic matter (SOM), moisture content, and selected heavy metals. The distribution of six metals, namely, Pb, Cd, Hg, Ni, Mn, and Fe, in roots, stem, and leaves of the plants was determined in two stages of growth after 5 weeks and 10 weeks. All soil and plant samples were microwave digested and subjected to heavy metal analysis using the ICP-OES, GFAAS, and CVAAS. The pH of the coal mine dump contaminated soil decreased with an increase in contamination. Both the SOM and CEC values decreased, which increases the availability of elements, by providing more binding sites in the soil. Relatively, the red herbs had higher elemental concentrations than the green herbs. Both plants recorded high manganese accumulation. No mercury was detected in the soils or plants.
Environmental problems posed by municipal solid waste (MSW) are well documented. Scientifically designed landfills and/or open dumpsites are used to dispose MSW in many developed and developing countries. Non-availability of land and need to reuse the dumpsite space, especially in urban areas, call for rehabilitation of these facilities. A variety of options have been tried to achieve the goals of rehabilitation. In the last couple of decades, phytoremediation, collectively referring to all plant-based technologies using green plants to remediate and rehabilitate municipal solid waste landfills and dumpsites, has emerged as a potential candidate. Research and development activities relating to different aspects of phytoremediation are keeping the interest of scientists and engineers alive and enriching the literature. Being a subject of multi-disciplinary interest, findings of phytoremediation research has resulted in generation of enormous data and their publication in a variety of journals and books. Collating data from such diverse sources would help understand the dynamics and dimensions of landfill and dumpsite rehabilitation. This review is an attempt in this direction.
Chet, I.; Raskin, I. Mechanisms of cadmium mobility and accumulation in Indian mustard
- D E Salt
- M Blaylock
- N P B A Kumar
- V Dushenkov
- B D Ensley
Salt, D.E.; Blaylock, M.; Kumar, N.P.B.A.; Dushenkov, V.; Ensley, B.D.; Chet, I.; Raskin, I. Mechanisms of cadmium mobility and accumulation in Indian mustard. Plant Physiol. 1995, 109, 1427– 1433.
In Why Phytoremediation-Phytoremediation is the Most Cost-Effective Approach for Many Sites. IBC's Second Annual Conference on Phytoremediation
- B D Ensley
Ensley, B.D. In Why Phytoremediation—Phytoremediation is the Most Cost-Effective Approach for Many Sites, IBC's Second An-nual Conference on Phytoremediation, Seattle, WA, June 18–19, 1997.
Phytoremediation potential of Amaranthus sp. for heavy metals contaminated soil of oil producing territory
- A Bigaliev
- K Boguspaev
- E Znanburshin
Bigaliev, A.; Boguspaev, K.; Znanburshin, E. Phytoremediation po-tential of Amaranthus sp. for heavy metals contaminated soil of oil producing territory, In 10th Annual International Petroleum Envi-ronmental Conference, Houston, TX, Nov 10–14, 2003.
The cultivation of amaranth as a tropical leaf veg-etable with special reference to South Dahomey
- G J H Grubben
Grubben, G.J.H. The cultivation of amaranth as a tropical leaf veg-etable with special reference to South Dahomey; C.D.o.A. Research, Ed.; Royal Tropical Institute: Amsterdam, 1976.
Raskin, I. Phytoremediation
- D E Salt
- M Blaylock
Salt, D.E.; Blaylock, M.; Raskin, I. Phytoremediation. Annu. Rev. Plant Physiol. Plant Mol. Biol. 1998, 49, 643–668.
Microwave digestion of plant material for trace element determination
- B Zunk
- M Planck
Zunk, B.; Planck, M. Microwave digestion of plant material for trace element determination. Anal. Chim. Acta 1990, 236, 337– 343.
- Brooks R. R.