scholarly journals Changes in Anatomical Features of Chromolaena Odorata during Phytoaccumulation of Heavy Metals

Author(s):  
G.O. Omoregie ◽  
B. Ikhajiagbe

The present study investigated the accumulation of selected HMs by Chromolaena odorata and the concomitant effects on leaf anatomical features. Top soils were collected from a marked plot and pooled together to obtain a composite sample. The soil was sun-dried to constant weight and measured into experimental pots at 20kg each). The pots were divided into 5 metal groups with 3 sub-groups each. Each group was polluted with Manganese (Mn), Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) in their respective chloride forms. Concentrations of the metals in the soil were initially based on their respective ecological screening value/benchmark (ESV). The ESV values for the 5 HMs were 50, 4, 100, 50 and 50 mg/kg respectively. Within each group, the respective HMs was applied in 3 concentrations of 1ESV, 3ESV and 5ESV. The control experiment consisted of plants grown in soils with no exogenous application of the test metals. The experiment was triplicated. Twenty hours later, equal sized stem cuttings of C. odorata (2.0 – 2.3cm in thickness, 30 cm in length) were planted per experimental pot. Six months later, results showed significant accumulation of metals in plant stem, leaves, and most especially the root. Mn was the most accumulated HM in all plant parts (9.22 – 17.86 mg/kg), compared to Cd (0.85 – 1.66 mg/kg).Significant changes in folial anatomy were reported in HM-impacted plants compared to the control. There were more upper epidermal stomata (270 – 353 mm2) in Mn-exposed plants compared to the others. Increase in vascular bundle thickness (p<0.01) was reported in HM-exposed plants compared to control. Highly significant decrease in stem parenchyma thickness (p<0.01) never the less parenchyma thickness of HM-exposed plants ranged from 46.37 – 49.53 µm in Zn and Pb-exposed plants compared to 79.23 µm in the control.

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2149-2152 ◽  
Author(s):  
A. Grappelli ◽  
L. Campanella ◽  
E. Cardarelli ◽  
F. Mazzei ◽  
M. Cordatore ◽  
...  

Experiments on the real possibility of employing microorganisms to capture inorganic polluting substances, mainly heavy metals from urban and industrial wastes, are running using bacteria biomass. Many strains of Arthrobacter spp., gram-negative bacteria, diffused in the soil also inacondition of environmental stresses, have been proved to be particulary effective in heavy metal capture (Cd, Cr, Pb, Cu, Zn). The active and passive processes in accumulation of metals by bacteria were studied. Our experiments have been done on fluid biomass and on a membrane both for practical use and for an easy recovery.


2011 ◽  
Vol 138-139 ◽  
pp. 1149-1155 ◽  
Author(s):  
Yi Dong Guan ◽  
Ye Hong Du ◽  
Zhen Dong Li ◽  
An Cheng Luo

This paper reports the concentration of heavy metals (Cr, Cu, Zn, Cd and Pb) in the soils and rices surrounding the abandoned rural waste dumping sites in Ningbo. Igeo (geoaccumulation index) was calculated to assess the contamination degree of heavy metals in soils. The mean contents of Cr, Cu, Cd, Zn and Pb of soils were 33.3, 24.1, 1.5, 118.9 and 45.6 mg/(kg DW) (dry weight), respectively. All of them were much higher than that of the reference value (i.e. CK), but there were no coherent trend of the metal contents within 1-120m distance from the dumping site. Igeo of heavy metals reveals the order of Cd>Cu>Cr>Pb>Zn, and the contamination assessment of soils using Igeo indicate the moderate Cd pollution, while the soils were unpolluted-moderately overall by Cr, Cu, Zn as well as Pb. The heavy metal contents in root, stem & leaf and rice grains were all remarkable higher than that of the CK at 20-120 m distances, and the heavy metal contents in root were evidently much higher than other plant parts, while those in rice grain were lowest, indicating the great bioaccumulation trend of heavy metals. Although the metal contents in the rice grain were within the legislation limit, its bioaccumulation trend of heavy metals was remarkable, whose contents were 4.38-fold for Cr, 1.76-fold for Cu, 1.28-fold for Zn, 2.67-fold for Cd and 3.03-fold for Pb higher than that of reference value, respectively. Finally, we proposed a decentralized in-situ restoration approach for the dumping sites.


2020 ◽  
pp. 147-159
Author(s):  
Thangavelu Muthukumar ◽  
Selvam Dinesh-Babu

Investigamos el efecto de varias concentraciones (0,0-5,0 ppm) de cadmio (Cd) en la capacidad de regeneración; las características morfológicas y la acumulación de Cd en los esquejes de tallo de la verdura de hoja Talinum portulacifolium cultivada en cultivo hidropónico. El Cd retrasó la brotación de los esquejes en un 7%, la callosidad en un 8% y el enraizamiento en un 38%. Las diferentes concentraciones de Cd afectaron significativamente a los pesos fresco y seco de las partes de la planta, excepto las raíces. La acumulación de Cd fue mayor en los tallos que en las hojas (2,22 vs 0,57 ppm). El índice de tolerancia calculado osciló entre el 59% y el 88%. Basándose en las observaciones, se concluyó que el Cd interfiere con la regeneración de los esquejes de tallo de T. portulacifolium e implica preocupación sobre el consumo y el uso terapéutico de esta hortaliza de hoja que crece en suelos contaminados. We investigated the effect of various concentrations (0.0-5.0 ppm) of cadmium (Cd) on the regeneration ability; morphological characteristics and Cd accumulation in the leafy vegetable Talinum portulacifolium stem cuttings grown in hydroponic culture. Cd delayed sprouting of stem cuttings by 7%, callusing by 8% and rooting by 38%. Different Cd concentrations significantly affected fresh and dry weight of plant parts except roots. Accumulation of Cd was more in the stems than in leaves (2.22 vs 0.57 ppm). The calculated tolerance index ranged from 59% to 88%. Based on the observations it was concluded that Cd interferes with the regeneration of T. portulacifolium stem cuttings and imply concerns on the consumption and therapeutic use of this leafy vegetable growing on polluted soils.


2021 ◽  
Vol 29 (4) ◽  
pp. 391-402
Author(s):  
Pritam Mukherjee ◽  
Prosenjit Pramanick ◽  
Sufia Zaman ◽  
Abhijit Mitra

The present study aims to investigate the phytoremediation potential of zinc (Zn), copper (Cu), and lead (Pb) by two dominant mangrove associate species, Suaeda maritima, and Salicornia brachiata, found in the high saline supralittoral zone of Indian Sundarbans in four stations of the Hooghly-Matla estuarine complex during the premonsoon season (May 2019). We found that concentrations of biologically available heavy metals (HMs) in the ambient soil and bioaccumulated HMs within the vegetative plant parts occurred as per the order: Sagar South > Bakkhali > Jharkhali > Bali Island. The order of biologically available and bioaccumulated HMs was Zn > Cu > Pb. Interestingly, the selected HMs display high organ-specificity for both species with the highest enrichment in roots, followed by stems and leaves. We propose that these halophytes could be used as agents of phytoremediation and their farming would be effective in the ecorestoration of this deltaic complex in context to conservative pollutants.


1941 ◽  
Vol 19c (4) ◽  
pp. 99-105
Author(s):  
N. H. Grace

Greenwood cuttings of Deutzia Lemoinei, Symphoricarpus albus, and Weigela rosea and dormant cuttings of Lonicera tatarica were treated with a series of 32 talc dusts containing potassium acid phosphate at concentrations of 0, 0.1, 1.0, and 10%, in combination with 0 and 10% cane sugar, 0 and 50 p.p.m. ethyl mercuric bromide, and 0 and 1000 p.p.m. indolylacetic acid. The lower concentrations of phosphate tended to increase rooting and reduce mortality of two of the species of greenwood cuttings whereas the 10% concentration was ineffective or injurious. However, this concentration was favourable to the rooting of dormant cuttings. Indolylacetic acid treatment increased the number of rooted cuttings and the number and length of roots. Beneficial effects were indicated for organic mercury and cane sugar treatments. However, these were attributed largely to the combinations with phosphate and indolylacetic acid. The results indicate that the effectiveness of dusts containing indolylacetic acid in the treatment of plant stem cuttings may be increased by the addition of nutrient and disinfectant chemicals.


2014 ◽  
Vol 71 (2) ◽  
pp. 268-276 ◽  
Author(s):  
J. Vymazal ◽  
T. Březinová

The accumulation of heavy metals in plants is a function of uptake capacity and intracellular binding sites. The concentrations of heavy metals in plants growing in constructed wetlands vary considerably between species and systems but in general, the concentrations are within the range commonly found in natural stands. The highest concentrations are mostly found in roots, followed by rhizomes, leaves and stems. Unfortunately, concentration values are commonly used to evaluate the ‘accumulation’ of heavy metals, but this approach is not correct. In order to evaluate heavy metal accumulation, the biomass of particular plant parts must be taken into consideration. In addition, there are two other factors, which need to be taken into consideration when accumulation is evaluated, namely seasonality and distribution within the plant shoot. It has been found that the seasonal distribution of heavy metals in the biomass varies between heavy metals and mostly does not follow the pattern known for nutrients. In addition, the concentration and accumulation of heavy metals vary considerably within the shoot and this fact should be taken into consideration when analyses are carried out.


1986 ◽  
Vol 18 (3) ◽  
pp. 257-263 ◽  
Author(s):  
J. Garty ◽  
Margalith Galun ◽  
Y. Hochberg

AbstractThe lichen Caloplaca aurantia, when growing on concrete roof tiles, accumulates high concentrations of heavy metals. The uptake correlates with the ambient metal concentration. The results of lichen and substratum analyses of samples from a heavily polluted area indicate that the concentrations of metals in the lichen are many times higher than in the substratum. The relative content of the eight metals, Fe, Mn, Zn, Cu, Pb, Cr, Ni and Cd was determined. The content of Fe, Cr, Ni and Cd was not significantly different in the various tile zones sampled. Fe, Mn, Zn, Cu, Cr, Ni and Cd were mainly taken up by the lichen directly from the atmosphere. The uptake of these metals from the tile is almost negligible. The maximum uptake of Pb by C. aurantia from the tile glaze was 10.95°° of the total amount in the lichen. The presence of the lichen on the tiles prevents the penetration of Pb, Zn and Mn into the substratum.


2006 ◽  
Vol 63 (3) ◽  
pp. 276-280 ◽  
Author(s):  
Clístenes Williams Araújo do Nascimento

Phytoremediation of heavy metals is a biotechnology that extracts metals from soils and transfer them to plant. As hyperaccumulator species have demonstrated low potential for commercial phytoextraction, synthetic chelates have been successfully used to induce accumulation of metals by high-biomass plants. However, they pose serious environmental drawbacks regarding excessive amount of metals solubilized. In search for synthetic chelate-alternatives, this paper evaluate the performance of DTPA, EDTA, citric acid, oxalic acid, vanillic acid, and gallic acid in desorbing Cd, Pb, Zn, Cu, and Ni from soil. DTPA and EDTA were highly effective in desorbing Cd, Pb, Zn, Cu, and Ni from soil. However, the excessively high concentration of metals brought in solution by such chelates limits their application in the field. Citric and oxalic acids desorbed substantial quantities of Zn, Cu, and Ni if applied at 10 or 20 mmol kg-1. At the 20 mmol kg-1 dose, vanillic and gallic acids solubilized significant amounts of Zn, Ni, and Cd from soil. None of the tested low molecular weight organic acids substantially increased the Pb concentration in soil solution.


2021 ◽  
Vol 37 ◽  
pp. 00144
Author(s):  
Vasily I. Dorozhkin ◽  
Natalia A. Brichko ◽  
Natalia S. Pavlova ◽  
Galina I. Pavlenko

Every year, pollution by eco-toxicants of natural and anthropogenic origin is becoming more and more acute. Some of the most toxic among them are heavy metals, especially cadmium and lead. These elements do not decompose. Once released into the environment, these elements continue to circulate in water, soil, and air for a very long time, accumulating in plants and livestock products. Therefore, there is a problem of obtaining safe agricultural products in areas contaminated with heavy metals. In animal husbandry, synthetic and natural enterosorbents are used for obtaining safe products. For example, such enterosorbents are shungites, bentonites, diatomites, clays. We tested diatomite from the Kamyshlovskoye deposit at a dose of 5.0 g/kg of feed to reduce cadmium accumulation and lead during their combined intake. We investigated the feed intake of a combination of cadmium and lead at doses of 5.0 and 50.0 mg/kg feed. The result of this experiment is the accumulation of metals in the liver, kidneys, and bones, and, in addition, in the testes. The use of diatomite to reduce the accumulation of heavy metals has not been successful. There is an increase in lead accumulation in the liver, kidneys, and testes. The content of cadmium in diatomite is 3.86 ± 0.20 mg/kg, lead – 105.0 ± 7.2 mg/kg. The results obtained indicate that diatomite as a feed additive to reduce lead and cadmium intoxication did not show protective properties.


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