The influence of Cd concentration in growing substrate (0, 10, 20, 40 mg·dm⁻³) and AMF colonization of root system on growth, flowering, and Cd accumulation in osteospermum shoots were examined. Cd in the applied concentrations did not affect decorative value of osteospermum, no chlorosis or necrosis were observed on leaf margins frequently visible on leaves of other bedding plants. Cd at higher concentrations (20 and 40 mg·dm⁻³) lowered dry weights of shoots and roots in non-mycorrhizal plants. Mycorrhizal plants were lower and had lower dry weights of shoots and roots. Cd did not affect dry weights of shoots and roots in mycorrhizal plants. The effects of Cd and mycorrhization on flowering of osteospermum were negligible. Cd content of osteospermum shoots increased with the increasing content of Cd in growing substrate. Mycorrhizal plants grown in substrate containing 40 mg Cd·dm⁻³ accumulated more Cd in shoots than non-mycorrhizal plants. Obtained results showed that osteospermum is very tolerant to Cd toxicity and can accumulate great amount of Cd in shoots.
Large areas worldwide are polluted by cadmium (Cd) and lead (Pb). The objective of this study was to develop and verify a simple model for phytoextraction of Cd and Pb. Consequently, a new model was developed based on soil and plant responses to Cd and Pb pollutants. Polluted soils were packed into some pots. Land cress and spinach seeds were germinated in the pots. Results showed the more Pb and Cd-tolerance of land cress compared to spinach. Land cress dry matter was about 50 times more than that of spinach at same contaminations. For spinach, there was a threshold soil Pb concentration (600 mg kg⁻¹), beyond which plant is more efficient to uptake Pb. Results also indicated that the proposed model with linear sorption isotherm can reasonably well predict the time needed for remediation of soil Pb. However, the model could not provide a reasonable prediction for Cd remediation.
The aim of our research was to estimate the efficiency of monoaecian fibrous hemp (Cannabis sativa L., "Benico" variety) for heavy metals phytoextraction from soil-sludge substratum during anaerobic sewage sludge management in non-industrial sites. Below are the results from a pot experiment with hemp as a plant which phytoextracts zinc, copper and nickel. On the basis of heavy metals analysis in substratum it was ascertained that an increase of hemp biomass caused thirtyfold reduction of zinc, thirty-fivefold reduction of copper and tenfold reduction of nickel in light soil of sewage sludge fertilized in comparison with their concentration at the beginning of the pot experiment.
Field experiments were carried out from 1999 to 2001 with nine crops (red beet, field pumpkin, chicory, common bean, barley, white cabbage, maize, alfalfa and common parsnip) to determine the cadmium and lead accumulation and distribution in the plants' organs. Based on the obtained results, species suited for phytoremediation were selected. Within the red beet, field pumpkin, chicory, common bean, white cabbage and parsnip the maximum Cd and Pb content was found in leaves. The red beet was characterized by the highest cadmium concentration ratio (shoots/roots). The red beet and common parsnip were characterized by the highest lead concentration ratios (shoots/roots). The phytoremediation efficiency of the investigated crops depended on the biomass production and the possibility of metal accumulation in harvestable organs.
Salix viminalis is a plant widely applied as a source of renewable energy. It is also known as a possible biofilter for extraction of soil and water contaminants. The current study presents preliminary results on heavy metal ion uptake (Cu²⁺, Cr³⁺, Zn²⁺) by living plants of Salix viminalis. In relation, a new concept of further utilization of ion-enriched wood is proposed as raw material for carbon-based catalyst fabrication by heat treatment of metal-impregnated partly dried biomass. Particular attention is paid to the distribution of heavy metal ions along the plant stem, since one intends to exploit natural transport and distribution of metal ions in living plants. The uptake from water solution and subsequent accumulation of ions in plant tissues was investigated regarding the form in which ions were present in water solution. Accumulation rates were higher for ion complexes with EDTA in comparison to aqua complexes.
The objective of the presented studies carried out in the Department of Horticultural Plant Fertilization, University of Life Sciences in Poznań was the investigation of the influence of the introduced doses of cadmium and lead (soil pollution) on the yield of the particular organs of selected cultivars of Marigold (Tagetes erecta L.) and to check whether these plants are suitable to be planted on soils polluted with the mentioned metals. Plants used in the experiment were planted in individual outflowless containers in plastic tunnel. The studied cultivars of Marigold were planted in a substrate artificially polluted with cadmium and lead. The two heavy metals were introduced in the following doses: Cd – 0 (control); 1; 5; 10 mg dm⁻³, Pb – 0 (control); 100; 500; 1000 mg dm⁻³. Statistical analyses carried out in the present paper refer to the analysis of variance for leaf, stalk and inflorescence matters and the number of inflorescences. Analysis of the mean total yield of the particular cultivars grown in all substrates has shown that the highest total yield was reached by ‘Titania’ cultivar, in the second place was ‘Hawaii’ and the smallest yield was obtained from ‘Mann im Mond’. The smallest amounts of cadmium and lead, regardless of the applied dose, remained in the substrate in which ‘Hawaii’ cultivar was grown.
In the Department of Plant Fertilization, University of Life Sciences in Poznań, a vegetation experiment (in plastic tunnel) was carried out in which the substrate was artificially contaminated with cadmium and lead and three cultivars of Tagetes erecta L. were planted in it: ‘Mann im Mond’, ‘Hawaii’ and ‘Titania’. The substrate was artificially contaminated with increasing doses of metals: Cd – 0 (control); 1; 5; 10 mg dm⁻³; Pb: 0 (control); 100; 500; 1000 mg dm⁻³. The objective of studies was to investigate which organs of Tagetes erecta L. cumulated the greatest amounts of cadmium and lead, what amounts of Cd and Pb move from the substrate to the organs of the studied cultivars and whether the studied cultivars of Marigold are suitable for the remediation of soils polluted with cadmium and lead. The metals contained in the particular plant organs, after dry mineralization, were identified by the method of atomic spectrophotometer AAS-3 of Zeiss Company. In all studied cultivars, the highest contents of cadmium were found in leaves, smaller amounts were shown in stalks, while inflorescences contained the smallest Cd amounts. The highest amounts of lead in all studied cultivars were found in the stalks, smaller amounts in the leaves and the least amount was shown in the inflorescences The greatest contents of cadmium and lead were found in the organs of ‘Hawaii’ cultivar, both in the leaves, stalks and inflorescences. The studied cultivars of Tagetes erecta can be utilized for the remediation of soils polluted by heavy metals.
A pot experiment was established in 2006 to examine whether induced phytoextraction can remove copper from soils polluted with emissions from copper smelters. Two soils tested in the experiment were sand and loam in texture, and contained 620 and 510 mg⋅kg-1 Cu, respectively. Maize was used as a testing plant. Two chelating agents: EDTA and biodagradable EDDS were introduced into the soils at the rates of 0.2; 0.5 and 1.0 mmol⋅kg-1 to intensify the process of Cu phytoextraction. The results that have been already published indicated that application of both chelators caused increase in Cu uptake by plants in 2006, although the concentrations of Cu in biomass were far below those required for effective phytoextraction. Additionally, both chelators caused intensive leaching of metals from soils. This paper focuses on the carryover effects observed in the subsequent year, 2007, certainly caused by the application of chelators. EDTA, particularly when applied at the highest rate, caused considerable deterioration of plant growth, reduction of plant yields and increased uptake of Cu by plants grown in both soils. The plants showed unquestionable effects of copper phytotoxicity. In the plots where EDDS was applied, a small decrease in yield was observed in the case of plants grown on sandy soil, whereas in plants grown on loamy soil a significant increase in plant yields and decrease in Cu concentrations in shoot biomass occurred compared with the control plots. Cu and Fe concentrations in plant shoots were positively correlated with each other, and the plants with the highest concentrations of Cu also contained the highest concentrations of Fe. Application of the chelating agents, particularly EDTA, in 2006 caused a long-lasting increase of Cu and Fe solubility in soil, and plant uptake of those elements in 2007 correlated positively with soil concentrations of soluble metal forms, extracted with 1 mol⋅dm-3 NH4NO3 and 0.01 mol⋅dm-3 CaCl2.
Berkheya coddii Roessler (Asteraceae), an endemic herbaceous and perennial nickel-hyperaccumulating plant growing on Ni-enriched ultramafic soils in South Africa, is perceived as a promising species for phytoremediation and phytomining due to its large biomass production and high Ni content. Total concentrations of a number of elements in mature leaves, soil and related bedrock were obtained. The average Ni concentration in leaves was 18,000 µg · g-1 dry mass, whereas in soil and bedrock the total amount of Ni was 1,300 µg · g-1 and 1,500 µg · g-1, respectively. Exceptionally high average Ni concentrations (55,000 ± 15,000 µg · g-1, n = 6) were found in B. coddii leaves from Songimvelo Game Reserve, including the highest-ever reported concentration of Ni in leaves (76,100 µg · g-1 - maximum value in a single sample). Young plants grown in pots with ultramafic soil accumulated small quantities of Cd, Pb or Zn, but the concentrations of these elements increased after the addition of metal solutions to the soil. Excised shoots immersed in concentrated solutions of Cd, Ni, Pb or Zn accumulated large amounts of these metals in the leaves.
Field experiments were carried out near Kraków (Poland), between 1999 and 2001, with nine crops (red beet, field pumpkin, chicory, common bean, barley, white cabbage, maize, alfalfa, common parsnip) to determine zinc and copper accumulation and their distribution in the plants’ tissues. Based on the results, species suitable for phytoremediation were selected. Field pumpkin and red beet were characterized by the highest zinc accumulation, especially in the leaves (119.14 and 64.97 mg·kg⁻¹ d. w. respectively). In the case of alfalfa, field pumpkin, and barley the maximum Cu content was found in the roots (35.81, 25.74, 15.92 mg·kg⁻¹ d. w. respectively). The field pumpkin, chicory, and red beet were characterized by the highest zinc concentration ratios (shoots/roots): 2.8, 2.2, 2.0. Concentration ratios for copper were within the range: 0.1 (barley) – 1.4 (common parsnip).
The aim of the research was to estimate efficiency of monoaecian fibrous hemp (Cannabis sativa L., "Benico" variety) for phytoextracting heavy metals from soil-sludge substrate during anaerobic sewage sludge treatment at non-industrial sites. Hemp is known to be an efficient lead, chromium and cadmium phytoextractor from soils, though these heavy metals cannot be found among plants nutrients. Heavy metals analysis of the substrate has shown that an increase in hemp biomass led to reducing lead, chromium and cadmium concentrations by a factor of six, twelve and nearly three, respectively. The effect was observed in light soil fertilised with sewage sludge and compared against respective metals concentration at the beginning of the pot experiment.