Phytoremediation Of Lead Research Articles

Phytoremediation of Lead: What Works, What Doesn’t

Phytoremediation of Lead: What Works, What Doesn’t

Poplar response to cadmium and lead soil contamination

An outdoor pot experiment was designed to study the potential of poplar (Populus nigra 'Italica') in phytoremediation of cadmium (Cd) and lead (Pb). Poplar was treated with a combination of different concentrations of Cd (w = 10, 25, 50mgkg−1 soil) and Pb (400, 800, 1200mgkg−1 soil) and several physiological and biochemical parameters were monitored including the accumulation and distribution of metals in different plant parts (leaf, stem, root). Simultaneously, the changes in the antioxidant system in roots and leaves were monitored to be able to follow synergistic effects of both heavy metals. Moreover, a statistical analysis based on the Random Forests Analysis (RFA) was performed in order to determine the most important predictors affecting growth and antioxidative machinery activities of poplar under heavy metal stress. The study demonstrated that tested poplar could be a good candidate for phytoextraction processes of Cd in moderately contaminated soils, while in heavily contaminated soil it could be only considered as a phytostabilisator. For Pb remediation only phytostabilisation process could be considered. By using RFA we pointed out that it is important to conduct the experiments in an outdoor space and include environmental conditions in order to study more realistic changes of growth parameters and accumulation and distribution of heavy metals. Also, to be able to better understand the interactions among previously mentioned parameters, it is important to conduct the experiments during prolonged time exposure., This is especially important for the long life cycle woody species.

Phytoextraction of Lead from Soil by Parthenium hysterophorus Linn.

In recent years, heavy metals toxicity has increased due to frequent use of fertilizer in soil. Which causes hazardous to the food. Parthenium Hysterophorus Linn. had shown characteristics against lead toxicity in the soil. Phytoremediation (phytoextraction) of lead using above plant to extract lead from lead contaminated soil. Contamination of soil by heavy metals is of wide spread occurrence as a result of human, agriculture and industrial activities.The contamination is a risk to all organism including human. Entrance to the toxicity metals into the human body beyond threshold limits, causes many disease and health abnormalities. Although lead is not an essential element for the plants, it gets absorbed and accumulated in different parts of the plant. Parthenium hysterophorus linn. is a weed, distributed throughout the tropics of the world and plains in India. Remediation of soil contaminated with lead using parthenium hysterophorus appear to have great potential for cleaning of lead contaminated soil. The phytochemical present in Parthenium hysterophorus linn. has good potential of phytoremediation in the removal of lead from contaminated soil and its optimum removal of lead was found to be 223.8 mg/kg of soil at a concentration of 600mg of lead/kg of soil. Emerging cleans up technologies for phytoremediation of lead (Pb) as phytoextraction using Parthenium hysterophorus linn. having the potential to provide environmentally sound and economically viable remedies for the cleaning of lead contaminated soils.Further, more research can be carried out to genetically modified Parthenium hysterophorus linn. for better phytoremediation of lead and molecular studies greatly help in understanding the mechanism and enhancing the efficiency of phytoremedation of Parthenium hysterophorus linn. Furthermore, advance research can be achieved by isolating the active principle from Parthenium hysterophorus linn, involved in great potential for cleans up soil contaminated with lead.

Phytoremediation of Lead by Vigna mungo

Phytoremediation of Lead by Vigna mungo

Phytoremediation of lead and cadmium by thornless honey loccust trees’(Gleditsia triacanthos L. var. inermis) in contaminatedsoil near the Tehran-Karaj highway

Phytoremediation is an emerging technology that uses plants to remove pollutants from contaminated sites. The present study examined the absorption of heavy metals by Gleditsia triacanthos L. var. inermis, a tree species planted in the landscape in Tehran-Karaj highway (Iran). This study was arranged in a split plot design with three replications. Experimental treatments included distances of planted trees from highway (30, 65, and 80 m) and three different sampling times (i.e. opening of leaves, late of June, and before the fall). The results showed that with the passage of time and approaching the fall, Pb concentration significantly increased. The highest concentration of Cd was observed in the mid-growth period. With increasing the distance, chlorophyll significantly increased. However, chlorophyll b and total chlorophyll were not influenced by the distance from the highway. The interaction of the distance and sampling time demonstrated that in the nearest distance from the highway, the concentration of chlorophyll decreased with the passage of time, while in the distance of 65 and 80 m from the highway, the concentration of chlorophyll increased in the middle of the growth period. In the nearest distance from the highway, the concentration of Pb significantly increased with the passage of time. By approaching fall, Pb concentration increased in 65 and 80 m from the highway. In the nearest distance from the highway, during mid-growth period, Cd concentration reached its maximum level.

Effects of lead contamination in soils on dry biomass, concentration and amounts of lead accumulated in three tropical pasture grasses

AbstractA greenhouse pot‐experiment was conducted to evaluate the phytoremediation abilities of three tropical pasture grasses (signalgrass, napiergrass and atratum) in response to two types of soils (Kunigami‐maji and Shimajiri‐maji) contaminated with three levels of lead (0, 150 and 300 mg kg–1). The results demonstrated that the dry biomass, lead concentration and the accumulated amounts were different among the plant species and between the soil types. The amounts of dry matter in three tropical pasture grasses grown on Kunigami‐maji soil were higher than that on Shimajiri‐maji soil. On both soils, lead concentration of roots was higher than that of shoots, and it was suggested that transportation of lead from roots to shoots was restricted in these plants. The lead accumulated amounts per plant grown on Kunigami‐maji soil were higher than that on Shimajiri‐maji soil. And, on Kunigami‐maji soil, accumulation of lead was relatively high in both shoots and roots of signalgrass and atratum, while, in napiergrass, the high level of lead was found only in roots. Amounts of lead extracted from the shoots of signalgrass, napiergrass and atratum grown on Kunigami‐maji soil contaminated with the highest lead level of 300 mg kg–1 were 1.64, 0.17 and 0.92 mg plant–1, respectively. As Kunigami‐maji had lower soil pH than Shimajiri‐maji, it can be suggested that lower soil pH may enhance lead bioavailability and uptake by the tropical pasture grasses. In conclusion, signalgrass and atratum could be useful for phytoremediation of lead contaminated soil, especially on Kunigami‐maji soil.

Influence of plant growth regulators and humic acid on the phytoremediation of lead by maize in a Pb-polluted calcareous soil

ABSTRACTPhytoremediation is a cleanup technology for the removal of contaminants from polluted soils. The influences of humic acid (HA) and four plant growth regulators, i.e. gibberellic acid, salicylic acid, 3-indoleacetic acid, and 6-benzylaminopurine on the phytoremediation of Pb by maize were investigated in a pot trial on a Pb-contaminated soil. Foliar spray of 6-benzylaminopurine and salicylic acid significantly increased mean root dry matter but none of growth regulators had a significant effect on that of shoot. Addition of HA decreased root dry matter and had no significant effect on that of shoots. Application of all growth regulators except gibberellic acid significantly increased root Pb uptake. Application of salicylic acid significantly increased mean uptake efficiency and shoot Pb concentration and uptake. Although addition of HA significantly increased mean phytoextraction and translocation efficiencies, these responses were mainly attributed to the role of HA in the reduction of both root dry weight and Pb uptake, meaning that HA is not promising in Pb phytoremediation by maize. Among the four plant growth regulators evaluated, salicylic acid was the most effective in enhancing phytoremediation through phytostabilization of Pb.

Enhancement of Lead Phytoremediation by Perennial Ryegrass (Lolium perenne L.) Using Agent of Streptomyces pactum Act12

It has been well recognized that microbes can assist phytoremediation of lead (Pb) by promoting plant growth and metal uptake. However, little is known about the potential of soil inoculation with actinomycetes to enhance Pb uptake and translocation in plants, particularly in semi-arid water-deficient areas. This study was focused on exploring the resistance of a soil actinomycete strain (Streptomyces pactum Act12) to Pb and its effects on plant growth, antioxidant responses, Pb uptake and translocation in perennial ryegrass (Lolium perenne L.). Special attention was given to experimental conditions in semi-arid area in Northerwest China. A fermentation culture of Act12 was applied in powder form to soil with or without Pb treatment (0–1,000 mg kg-1), and ryegrass plants were immediately grown in this soil, in pots, for 60 days under 20% relative soil moisture. Act12 showed tolerance to up to 1,200 mg Pb L-1 in plate culture and well colonized the soil containing less than 500 mg Pb kg-1. Under Pb stress, inoculated plants had higher biomass with greater plant height and root tiller number than the uninoculated controls. Additionally, higher catalase, superoxide dismutase and peroxidase activities were detected in leaves of inoculated plants under Pb stress. Inoculating soil with Act12 significantly increased Pb concentrations and uptake in plants grown in soil containing 200 to 1,000 mg Pb kg-1. The translocation and bioconcentration factors of inoculated plants were 10.5–36.2% and 37.3–133.1% higher than uninoculated plants, respectively. Streptomyces pactum Act12 can enhance Pb phytoremediation by perennial ryegrass and its powder form facilitates the use in semi-arid areas.

Effectiveness of arbuscular mycorrhizal fungi in phytoremediation of lead- contaminated soil by vetiver grass

ABSTRACTA greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of lead (Pb)-contaminated soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design. Factors included four Pb levels (50, 200, 400, and 800 mg kg−1) as Pb (NO3)2, AM fungi at three levels (non mycorrhizal (NM) control, Rhizophagus intraradices, Glomus versiforme). Shoot and root dry weights (SDW and RDW) decreased as Pb levels increased. Mycorrhizal inoculation increased SDW and RDW compared to NM control. With mycorrhizal inoculation and increasing Pb levels, Pb uptake of shoot and root increased compared to those of NM control. Root colonization increased with mycorrhizal inoculation but decreased as Pb levels increased. Phosphorus concentration and uptake in shoot of plants inoculated with AM fungi was significantly higher than NM control at 200 and 800 mg Pb kg−1. The Fe concentration, Fe and Mn uptake of shoot in plants inoculated with Rhizophagus intraradices in all levels of Pb were significantly higher than NM control. Mycorrhizal inoculation increased Pb extraction, uptake and translocation efficiencies. Lead translocation factor decreased as Pb levels increased; however inoculation with AM fungi increased Pb translocation.

Potential use of Sorghum bicolor and Carthamus tinctorius in phytoremediation of nickel, lead and zinc

Metals are very common contaminants in the soil. High-yielding biomass crops offer good potential for the phytoremediation of soils contaminated with heavy metals. Biomass fuel crops grown on contaminated land have several advantages as site remediation combined with bioenergy production. In this context, two energy crops, Sorghum bicolor and Carthamus tinctorius, were grown hydroponically to assess their potential use in phytoremediation of nickel (Ni), lead (Pb) and zinc (Zn) and biomass production. The experiment was carried out in a growth chamber using half-strength Hoagland’s solution spiked separately with five concentrations for Ni, Pb and Zn (between 5 and 100 mg L−1). Shoot and root biomass were determined and analyzed for their metals contents. Results showed that the tested plants were able to uptake Ni, Pb and Zn. Furthermore, roots accumulated more metals than shoots. Ni seems to be more toxic than Zn and Pb. In fact, both species were unable to grow at Ni concentration above 10 mg L−1. Metal toxicity ranked as follows: Ni > Zn > Pb. High toxicity symptoms and biomass reduction were observed at concentrations of Pb and Zn above 25 mg L−1 for both species. S. bicolor was more efficient than C. tinctorius in metal uptake due to the high biomass production and the relatively high shoot concentration of metal. S. bicolor could be successfully used in phytoremediation applications in marginal soils with moderately heavy metal contamination. However, results obtained through the hydroponic experiment need to be confirmed by field experiments.

Phytoremediation of lead using corn in contaminated agricultural land—An in situ study and benefit assessment

Phytoremediation is an environmentally friendly and economically feasible remediation technology for mitigating soil contamination in agricultural lands. However, phytoremediation can be a slow process, and for highly contaminated soils this approach would require hundreds to thousands of years to meet soil environmental quality standards. Such a long period of phytoremediation is relatively unfeasible without economic revenue from crop production. This study involves growth of corn in plots of lead-contaminated agricultural land with Pb concentrations of about 6000mg/kg. Our results showed that Bright Jean No. 7 corn was highly tolerant to lead, as evidenced by minimal effects on its growth and biomass production. Annually, each hectare of corn could produce up to 93.4 tons of dry matter and removed up to 7.2kg of lead. The corn biomass grown on such contaminated fields could be used as a bioenergy fuel, and each hectare of corn biomass could produce 1545GJ of thermal energy every year, which is equivalent to the heat from combustion of 57 tons of hard coal. The lead content in the corn kernel was less than the EU standard limit for animal consumption. Each hectare could produce approximately 25 tons of corn grains for animal feed per year, and the remaining parts of the plant could be used as the bioenergy fuel to generate heat energy equivalent to 40 tons of hard coal.

Lead phytoremediation of Rosmarinus officinalis and its effect on the plant growth

This project was conducted to evaluate lead absorption, accumulation rate and the effect of this metal on growth of Rosmarinus officinalis in Padina Research and Development greenhouse, Mashhad, Iran. The pot experiment was conducted in completely randomized design with 4 replications and 5 lead concentrations (0, 200, 400, 800 and 1000 µM). Root growth, stem growth, lead accumulation rate in root, lead accumulation rate in shoot, biological and transfer factors were measured. Analysis of variance indicated that root and stem growth decreased in treated plants with lead compared to control. No symptoms of lead poisoning were observed in plants. Lead accumulation rate were increased in root and stem with 953.5mg/kg and 1507.50mg/kg, respectively. According to the results, lead transfer and biological factors were higher than 1 in all treatments and were reached to 1.81 and 23, respectively. Considering that a plant is lead hyper-accumulator, can save higher than 1000mg/kg of it and has higher than 1 of biological and transfer factors. So this plant is considered as a hyper-accumulator plant.

Phytoremediation of lead (Pb) and Arsenic (As) by Melastoma malabathricum L. from Contaminated Soil in Separate Exposure

This study was conducted to investigate the uptake of lead (Pb) and arsenic (As) from contaminated soil using Melastoma malabathricum L. species. The cultivated plants were exposed to As and Pb in separate soils for an observation period of 70 days. From the results of the analysis, M. malabathricum accumulated relatively high range of As concentration in its roots, up to a maximum of 2800 mg/kg. The highest accumulation of As in stems and leaves was 570 mg/kg of plant. For Pb treatment, the highest concentration (13,800 mg/kg) was accumulated in the roots of plants. The maximum accumulation in stems was 880 mg/kg while maximum accumulation in leaves was 2,200 mg/kg. Only small amounts of Pb were translocated from roots to above ground plant parts (TF < 1). However, a wider range of TF values (0.01–23) for As treated plants proved that the translocation of As from root to above ground parts was greater. However, the high capacity of roots to take up Pb and As (BF > 1) is indicative this plants is a good bioaccumulator for these metals. Therefore, phytostabilisation is the mechanism at work in M. malabathricum's uptake of Pb, while phytoextraction is the dominant mechanism with As.

Investigation of Arbuscular mycorrhizal Fungus and EDTA Efficiencies on Lead Phytoremediation by Sunflower in a Calcareous Soil

ABSTRACT Lead (Pb) contamination of soils is a widespread problem. Mycorrhizal inoculation and synthetic chelators such as ethylenediaminetetraacetic acid (EDTA) may be useful for improving phytoremediation efficiency in Pb-contaminated soils. A greenhouse experiment was performed to study the influence of inoculation with arbuscular mycorrhizal fungus (AMF), Glomus mosseae, and addition of EDTA on phytoremediation of Pb by sunflowers (Helianthus annuus) in a calcareous soil. The experiment was a completely randomized design in a factorial arrangement with five levels of Pb, two levels of mycorrhizal treatments, and two levels of EDTA. Inoculation increased root colonization as Pb levels increased, but the addition of EDTA decreased it. Shoot and root dry matter yields increased by inoculation; however, they decreased with EDTA and Pb levels in co-application treatments. Pb concentration in shoots was significantly higher than that in roots, indicating a translocation factor greater than 1. Inoculation or addition of EDTA significantly increased Pb in roots and its translocation to shoots. The uptake index (UI) value increased in co-application of EDTA and AMF and the individual application of them; it is, therefore, concluded that both AMF and EDTA are effective in phytoremediation of Pb by sunflowers in the studied soil.

Pyrolysis of Hyperaccumulator Plants Used for the Phytoremediation of Lead Contaminated Soil

This study focuses on the phytoremediation of lead (Pb) contaminated soil by hyperaccumulator plants. In this study, pyrolysis was utilized for the stabilization of Pb into a solid product. In the first stage of the study, three types of phytoremediation plants were used, rape (Brassica napus), sunflower (Helianthus annuus), and corn (Zea mays). Their seeds were sown in simulated soils prepared with the addition of Pb compounds in a laboratory. The effect of chelate on the remediation capacity of the plants was investigated by the addition of EDTA in different concentrations. In this way, the transportation of Pb from the contaminated soils to the plants was examined. In the second stage, the initial plant compositions were determined by elemental analysis (C, H, N, and S), as well as a moisture, ash, volatile matter, and fixed carbon analysis. The contaminated hyperaccumulator plants were pyrolyzed at 500°C, with a heating rate of 35° C/min, in a fixed bed stainless steel (380 S) 240 cm 3 reactor. After pyrolysis, the Pb contents of the solid and liquid products were determined. A Toxicity Characteristics Leaching Procedure (TCLP) analysis was also utilized for the solid product. In this study, high phytoremediation efficiencies were observed for the phytoremediation of Pb contaminated soil using sunflower, corn, and rape, especially in the case of the chelate addition. Of the three plants, the best Pb removal efficiency (92%) from the soil was obtained with the rape. According to the pyrolysis results, the highest yields of liquid and solid products were obtained from the sunflower with gas products being obtained from the corn pyrolysis.

Utilization of kudzu as a lead phytoremediator and the impact of lead on selected physiological responses

Schwarzauer-Rockett, K., Al-Hamdani, S. H., Rayburn, J. R. and Mwebi, N. O. 2013. Utilization of kudzu as a lead phytoremediator and the impact of lead on selected physiological responses. Can. J. Plant Sci. 93: 951–959. This study was carried out to evaluate kudzu [Pueraria montana var. lobata (Willd.)] in lead phytoremediation. The impact of lead (PbNO3) concentrations of 100 and 200 mg L−1 on plant growth, photosynthetic pigments, photosynthesis, and stomatal conductance were evaluated. Additionally, concentrations of phenolic compounds and anthocyanin were determined. The lead was dissolved in 0.142 g L−1 ethylenediaminetetraacetic acid (EDTA) and an EDTA control treatment was added to evaluate the impact of EDTA on the above selected plant responses. Root accumulation of lead was significantly higher than in the shoot. Kudzu growth in response to the presence of lead and EDTA in the Hoagland's solution was similar to that of the EDTA control, except for plants growing at 200 mg L−1, which showed significantly lower root dry weight. Total phenolic compounds increased with the presence of EDTA and lead in the Hoagland's solution. Photosynthetic rate, stomatal conductance, chlorophyll a and chlorophyll b, carotenoids, and anthocyanin were not different (P≤0.05) among the treatments, with the exception that carotenoids were significantly higher in plants growing in the presence of EDTA without lead compared with 200 mg L−1 lead concentration. Kudzu accumulated most of the lead in the root and therefore can be considered as a rhizofiltrator. As kudzu was able to accumulate 1.02% (wt/wt) of lead it can be considered a hyper-accumulator.

Isolation of Burkholderia cepacia JB12 from lead- and cadmium-contaminated soil and its potential in promoting phytoremediation with tall fescue and red clover

Phytoremediation combined with suitable microorganisms and biodegradable chelating agents can be a means of reclaiming lands contaminated by toxic heavy metals. We investigated the ability of a lead- and cadmium-resistant bacterial strain (JB12) and the biodegradable chelator ethylenediamine-N,N'-disuccinic acid (EDDS) to improve absorption of these metals from soil by tall fescue and red clover. Strain JB12 was isolated from contaminated soil samples, analysed for lead and cadmium resistance, and identified as Burkholderia cepacia. Tall fescue and red clover were grown in pots to which we added JB12, (S,S)-EDDS, combined JB12 and EDDS, or water only. Compared with untreated plants, the biomass of plants treated with JB12 was significantly increased. Concentrations of lead and cadmium in JB12-treated plants increased significantly, with few exceptions. Plants treated with EDDS responded variably, but in those treated with combined EDDS and JB12, heavy metal concentrations increased significantly in tall fescue and in the aboveground parts of red clover. We conclude that JB12 is resistant to lead and cadmium. Its application to the soil improved the net uptake of these heavy metals by experimental plants. The potential for viable phytoremediation of lead- and cadmium-polluted soils with tall fescue and red clover combined with JB12 was further enhanced by the addition of EDDS.

The comparisons between Picea abies and Pinus sylvestris in respect of lead phytoremediation potential

Nowadays, heavy metals pollution has made some environmental problems in the biosphere. The technique of phytoremediation is using the plants in removing these environmental pollutants .In this study, Forty five three- year old seedlings of Pinus sylvestris L and Picea abies (L.) Karst were planted in plastic pots that there were put in open area. For each species, fifteen pots were treated with three lead concentrations 0 (control), 800, and 1600 mg Kg-1. At the end of October the amounts of Pb in roots, stems, leaves and soil were measured using ICP. Random data in 15 repetitions were analyzed using one-way analysis of variance. The results indicated that unlike Picea abies, P. sylvestris was suitable as a lead phytoremediation plant. In 800 mg kg-1 the Pb accumulation in both parts of P. sylvestris roots and stems while in high concentration 1600 mg kg-1, maximum Pb accumulation was observed in roots and leaves. In the species Picea abies we didn't observe any significant differences in Pb absorption between treatment and control up to 800 ppm, while in 1600 ppm Pb concentration was transported to stems and leaves. Comparison between the remaining Pb in different treatment levels of each horizontal layer of soil in P.sylvestris seedlings showed there was a significant difference only in first layer of soil. In P.abies there were significantly differences in horizons first and third. In conclusion, Pinus sylvestris is more suitable for Pb phytoremediation than Picea abies. * Corresponding Author: Seyyedeh Mahdokht Maddah  s.m.maddah@iausr.ac.ir

A Comparison of Electrical Stimulation for Electrodic and EDTA-Enhanced Phytoremediation of Lead using Indian Mustard (Brassica juncea)

Department of Chemistry and Physics, Western Carolina University, Cullowhee, North Carolina 28723, U.S.A.Received June 14, 2012, Accepted June 18, 2012The use of plants to remove toxic metals from soil (phytoremediation) is emerging as a cost-effectivealternative to conventional methods for the removal of heavy metals from contaminated soil. Indian mustard(Brassica juncea) was used as the plant to accumulate high tissue concentrations of lead when grown incontaminated soil. For this study, the application of an electric field combined effectively with EDTA-enhanced phytoremediation. A stimulation of direct and alternating electric potential was compared andEDTA-enhanced phytoremediation of lead using Indian mustard has been performed. The effects ofexperimental parameters such as operating voltage with different concentration of EDTA, the number ofgraphite electrodes, and cultivation period on the removal of toxic metal were studied. Shoot leadaccumulations in Indian mustard increased as the concentration of EDTA and dc electric potential wasincreased. Two to four folds was increased when EDTA plus a dc electric potential was applied, compared toan ac electric potential. The maximum lead accumulation in the shoots was achieved by applying EDTA plusdc electric potential with 6 graphite electrodes.Key Words : Phytoremediation, Lead, Indian mustard, Electrodics, EDTAIntroductionPhytoremediation is the use of living plants and the plantprocesses to reduce hazardous materials in environment.

Erratum to “Lead phytoremediation: a field application in a Site of National Interest” [J. Biotechnol. 150S (2010) S287

Erratum to “Lead phytoremediation: a field application in a Site of National Interest” [J. Biotechnol. 150S (2010) S287