Manganese, nickel and zinc were determined in soils and 4 plants (2 cultivated: Brassica oleracea, Zea mays and 2 non cultivated: Rumex acetosa, Verbascum phlomoides) around the Coal Power Plant (CPP) - Agios Dimitrios, the largest CPP in... more
Manganese, nickel and zinc were determined in soils and 4 plants (2 cultivated: Brassica oleracea, Zea mays and 2 non cultivated: Rumex acetosa, Verbascum phlomoides) around the Coal Power Plant (CPP) - Agios Dimitrios, the largest CPP in Greece. In general, roots showed a higher metal content compared to the other over ground parts. This is more prominent in Brassica oleracea for all studied metals except zinc, where the highest zinc concentration is found in the sclerechyma (central vein) of the internal leaf. Thus, Brassica oleracea meets the objectives of phytoremediartion of lands contaminated by heavy metals. Periodically planting of Brassica oleracea could reduce the level of heavy metals in the area in order to clean up and prepare soils for other cultivations. The most contaminated leaves revealed a variation in epidermis roughness. In Verbascum phlomoides the multicellular, multilevel hairs on the leaf surface fixed a considerable number of air particles effectively. In co...
Research Interests:
Research Interests:
The distribution of natural K, Ra and Ra and artificial Cs has been investigated in nonvascular mosses (9 species) and lichens (10 species) and vascular gymnosperm (1 species), angiosperm trees and shrubs (3 species) over the... more
The distribution of natural K, Ra and Ra and artificial Cs has been investigated in nonvascular mosses (9 species) and lichens (10 species) and vascular gymnosperm (1 species), angiosperm trees and shrubs (3 species) over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece. Four lignite power plants producing about 70% of the electric energy of the country are to be found in this region. Both specific activity and transfer factors of these radionuclides have been determined by means of experiments. This study indicates that with regard to Ra and Cs, nonvascular lichens and mosses have a much higher transfer factor (2.27 for Ra and 43.77 Cs) compared with vascular plants (0.17 for Ra and 0.03 Cs), but a lower one for natural K (0.493 for lichens and mosses and respectively 1.190 for vascular plants). Compared with unpolluted areas (0.25 Bq/kg), the Ra specific activity in lichens and mosses was systematically higher (26.43 and 56.74 Bq/kg respectively).
Research Interests:
Gamma-radioactivity of a wide variety of plant samples was measured. Measurements showed that radioactivity in plants depended on the area of surface exposed, the developmental season of the plants, and on the external morphology of their... more
Gamma-radioactivity of a wide variety of plant samples was measured. Measurements showed that radioactivity in plants depended on the area of surface exposed, the developmental season of the plants, and on the external morphology of their above-ground parts. Autoradiographs on several plants showed the presence of radioactivity in certain spots (hot spots) which were distributed randomly on the surface of the plants and differed in size and activity.
Research Interests:
Research Interests:
Concentrations of potentially toxic elements (PTEs) (Al, As, Cd, Cr, Cu, Ni, Pb, and Zn) were measured in topsoil samples collected from parks in the cities of Salzburg (Austria), Thessaloniki (Greece), and Belgrade (Serbia) in order to... more
Concentrations of potentially toxic elements (PTEs) (Al, As, Cd, Cr, Cu, Ni, Pb, and Zn) were measured in topsoil samples collected from parks in the cities of Salzburg (Austria), Thessaloniki (Greece), and Belgrade (Serbia) in order to assess the distribution of PTEs in the urban environment, discriminate natural (lithogenic) and anthropogenic contributions, identify possible sources of pollution, and compare levels of pollution between the cities. An assessment of the health risks caused by exposure to PTEs through different pathways was also conducted. The study revealed that, with the exception of Pb in Salzburg, levels of PTEs in the soils in polluted urban parks were higher than in unpolluted ones, but still lower than those recorded in other European soils. Results of sequential analyses showed that Al, Cr, and Ni were found in residual phases, proving their predominantly lithogenic origin and their low mobility. In contrast, the influence of anthropogenic factors on Cu, Pb, ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The impact of human activities and environmental factors on the fluctuation of chemical and physicochemical parameters along the Pinios River and its tributaries was studied. Their seasonal variations throughout the years 1996-1998 are... more
The impact of human activities and environmental factors on the fluctuation of chemical and physicochemical parameters along the Pinios River and its tributaries was studied. Their seasonal variations throughout the years 1996-1998 are also presented. Most of the parameters (physical or chemical) measured in this survey exhibited high spatial and temporal variability. High temperatures during the warm period, attributed both to meteorological conditions and to the geographical relief of Thessalia plain, cause a restriction of the water flow, an accumulation of organic matter and the depletion of the dissolved oxygen in the water. Conductivity and hardness are high during the warm and wet period for different reasons. At the seaward part of the river high conductivity and hardness values indicate extended admixture of seawater. COD values fluctuated seasonally. Among the studied stations along the Pinios River the most polluted was the area where the river has passed the city of Larissa.
Research Interests: Geography, Environmental Management, Environmental Monitoring, Rivers, Climate, and 19 moreEutrophication, Multidisciplinary, Greece, Seasonality, High Temperature, Seasonal variation, Oxygen, Fresh water, Fertilizers, Human Activity, Dissolved Oxygen, Seasons, River Water Quality, Water Flow, Water Movements, Organic Matter, Hydrogen-Ion Concentration, Temporal Variability, and *Hot Temperature
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Radiometric determination of natural Ra, Ra, K and artificial Cs radionuclides distribution have been performed over the Kozani-Ptolemïda-Amynteon basin (Western Macedonia). Here there are localized four lignite power plants, accounting... more
Radiometric determination of natural Ra, Ra, K and artificial Cs radionuclides distribution have been performed over the Kozani-Ptolemïda-Amynteon basin (Western Macedonia). Here there are localized four lignite power plants, accounting for about 70% of the total production of Greece's electricity. Soil samples, 0 to 20 cm depths, from both uncultivated and cultivated soils have been investigated. No significant increase in
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
... T. SAWIDIS and MK CHETTRI Institute of Botany, Faculty of Biology ... The main pollution sources are automobile exhausts, central heating installations and petrochemical, metal processing and other heavy and light industries. ...
Research Interests:
Water loss in lichen species Cladonia convoluta (Lam.) and C. rangiformis (L.) Hoffm. after exposure to heavy-metal (Pb, Cu, or Zn) solutions, either as single compounds or in combination, have been studied in this laboratory. Water loss... more
Water loss in lichen species Cladonia convoluta (Lam.) and C. rangiformis (L.) Hoffm. after exposure to heavy-metal (Pb, Cu, or Zn) solutions, either as single compounds or in combination, have been studied in this laboratory. Water loss was reduced in Pb-treated C. convoluta, whereas in C. rangiformis it increased significantly with 10(-2) M Pb treatment. Water loss increased significantly (P = 0.05) after Cu treatment in C. convoluta but was significantly reduced (P = 0.05) in 10(-8) and 10(-6) M CuCl2-treated C. rangiformis. Similarly, water loss increased in all Zn-treated thalli but was significantly decreased (P = 0.05) in 10(-8) M treated C. rangiformis. A cumulative effect of Pb, Cu, and Zn was observed on water loss after uptake from mixed-metal solution. K+ efflux indicated the extent to which the plasma membrane presents an effective barrier to metal ion uptake.
Research Interests:
Research Interests:
ABSTRACT A comparative investigation of seven heavy metals (Cr, Mn, Fe, Ni, Cu, Cd and Pb) in mosses, lichens and trees over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece has carried out. In this region there are... more
ABSTRACT A comparative investigation of seven heavy metals (Cr, Mn, Fe, Ni, Cu, Cd and Pb) in mosses, lichens and trees over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece has carried out. In this region there are four lignite power plants producing about 70% of the electric energy of the country. Experiments have determined both concentrations of these elements and transfer factors that are defined as the ratio of the concentration of a given element in an investigated organism to the concentration of the same element in the soil. This study indicates that compared to trees, mosses and lichens have a higher capacity for absorbing and accumulating heavy metals. The conifer Pinusnigra seems to have a higher affinity for these metals than the other tree species, which is manifested in a better correlation of the distribution functions as well as greater values of transfer factor. Compared with unpolluted areas, the concentration of chromium, manganese, iron, nickel, cadmium and lead are systematically increasing in tree leaves in the vicinity of all four power plants.
Research Interests:
Research Interests:
... Costas V. Kavouridis c & Thomas D. Sawidis d pages 269-282. ... The Use of ICP-AES and Anodic Striping Voltammetry (ASV) to Determine the Level of Cadmium and Lead in River Water Samples from Kwa Zulu-Natal (KZ-N), South Africa.... more
... Costas V. Kavouridis c & Thomas D. Sawidis d pages 269-282. ... The Use of ICP-AES and Anodic Striping Voltammetry (ASV) to Determine the Level of Cadmium and Lead in River Water Samples from Kwa Zulu-Natal (KZ-N), South Africa. J. Trace Microprobe Techn., 18: 83–97. ...
Research Interests:
The possibility of using aquatic macrophytes and algae as bioindicators of water pollution is investigated. The use of cluster analysis enables the treatment of the analytical data in a global way, revealing hidden clusters of similar... more
The possibility of using aquatic macrophytes and algae as bioindicators of water pollution is investigated. The use of cluster analysis enables the treatment of the analytical data in a global way, revealing hidden clusters of similar behaviour between various biological species or sampling sites. A great number of species was collected from four rivers and fourteen coastal sites in Greece and were analysed for zinc, copper, cadmium, lead and manganese. The analytical data obtained were treated by hierarchical clustering, for marine algae and aquatic macrophytes separately.
Research Interests:
Research Interests:
Research Interests: Environmental Monitoring, Air pollution, Greece, Heavy metals, Copper, and 5 moreChromium, Nickel, Cadmium, Pinus, and Olea
Research Interests:
Research Interests:
Economical and bio-friendly approaches are needed to remediate dye-contaminated wastewater from various industries. In this study, a novel bacterial strain capable of decolorizing triarylmethane dyes was isolated from a textile wastewater... more
Economical and bio-friendly approaches are needed to remediate dye-contaminated wastewater from various industries. In this study, a novel bacterial strain capable of decolorizing triarylmethane dyes was isolated from a textile wastewater treatment plant in Greece. The bacterial isolate was identified as Aeromonas hydrophila and was shown to decolorize three triarylmethane dyes tested within 24 h with color removal in the range of 72% to 96%. Decolorization efficiency of the bacterium was a function of operational parameters (aeration, dye concentration, temperature, and pH) and the optimal operational conditions obtained for decolorization of the dyes were: pH 7-8, 35°C and culture agitation. Effective color removal within 24 h was obtained at a maximum dye concentration of 50 mg/L. Dye decolorization was monitored using a scanning UV/visible spectrophotometer which indicated that decolorization was due to the degradation of dyes into non-colored intermediates. Phytotoxicity studies carried out using Triticum aestivum, Hordeum vulgare, and Lens esculenta revealed the triarylmethane dyes exerted toxic effects on plant growth parameters monitored. However, significant reduction in toxicity was obtained with the decolorized dye metabolites thus, indicating the detoxification of the dyes following degradation by Aeromonas hydrophila.
Research Interests:
Research Interests:
... T. SAWIDIS and MK CHETTRI Institute of Botany, Faculty of Biology ... The main pollution sources are automobile exhausts, central heating installations and petrochemical, metal processing and other heavy and light industries. ...
Research Interests:
The present paper deals with chemometric interpretation of the bioindicating ability of mosses for heavy metal pollution in urban and rural areas of Greece. Fourteen different moss species collected at twelve sampling sites are included... more
The present paper deals with chemometric interpretation of the bioindicating ability of mosses for heavy metal pollution in urban and rural areas of Greece. Fourteen different moss species collected at twelve sampling sites are included in the study. Four heavy metals concentrations (lead, zinc, copper and cadmium) are determined in each of the totally 61 various samples (with respect to
Research Interests:
ABSTRACT Uptake of Pb, Cu and Zn by different epiphytic moss species Floribundaria floribunda (Doz. & Molk.) Fleisch., Taxiphyllum giraldii (C. Muell.) Fleisch. and Thuidium sparsifolium (Mitt.) Jaeg., an epilithic moss Thuidium... more
ABSTRACT Uptake of Pb, Cu and Zn by different epiphytic moss species Floribundaria floribunda (Doz. & Molk.) Fleisch., Taxiphyllum giraldii (C. Muell.) Fleisch. and Thuidium sparsifolium (Mitt.) Jaeg., an epilithic moss Thuidium delicatulum (L.) Mitt. and a leafy liverwort Ptychanthus striatus (Lehm. & Linderb.) Nees. was studied experimentally. The plant bodies were treated with single metal and mixed metal solutions of Pb(NO3)2, CuCl2 and ZnCl2 at different concentrations ranging from 10−10 to 10−2 mol L−1. Higher uptake of Pb, Cu and Zn by T. giraldii, T. sparsifolium and P. striatus than by F. floribunda and T. delicatulum was shown in both treatments. Compared with the single metal treatment, the uptake of Zn was very low at higher concentrations in the mixed metal treatment. A slight depletion of Zn was noticed in the long-term exposure. Leaching of naturally accumulated Zn from the mosses and leafy liverwort was also observed when treated with higher concentrated (10−4, 10−2 mol L−1) Pb(NO3)2 and CuCl2 solutions. Similarly, the leaching of naturally accumulated Cu was observed in leafy liverwort P. striatus with 10−2 mol L−1 Pb(NO3)2 and ZnCl2 treatments. However, insignificant changes were observed on naturally accumulated Pb and Cu in mosses. From these experiments, the epiphytic mosses T. giraldii and T. sparsifolium, which have high Cation exchange capacity and large leaf surface area, have been found to be suitable for assessing heavy metal concentration in a moderately or slightly contaminated environment.
Research Interests:
Research Interests:
Zinc toxicity in secretory cells caused a range of effects, mainly depending on metal concentration. Low concentrations activated nectary function increasing nectar secretion but secretion was greatly inhibited or stopped entirely by... more
Zinc toxicity in secretory cells caused a range of effects, mainly depending on metal concentration. Low concentrations activated nectary function increasing nectar secretion but secretion was greatly inhibited or stopped entirely by ongoing concentration. Water loss rate of zinc treated flower parts was significantly reduced whereas green sepals were dehydrated more rapidly in comparison to colored petals. The content of zinc, calcium, magnesium and manganese increased mainly in sepals under excess of zinc, but in the secreted nectar this metal was not evident. Morphological changes were observed in mucilage cells concerning the mucilage structure and appearance. The parenchymatic, subglandular cells displayed an early vacuolarization and cytoplasm condensation. Secretory hairs appeared to be thinner, the apical cell folded inwards and plasmolytic shrinkage became severe in all cells. The waxy cuticula showed an increased electron density. A plasmalemma detachment from the external cell walls was observed creating a gap between cell wall and plasmalemma. ER cisterns of all treated nectary hairs dominated the cytoplasm and electron dense deposits were seen within its profiles. A great number of other organelles were also present, showing electron dense deposits in their membranes as well. The vacuome was drastically reduced in all cells, except in the subglandular ones and electron dense membrane remnants were observed.
Research Interests:
... The results are discussed in relation with other plant glands, especially with the closely related Abutilon nectaries. Th. Sawidis, E. P. Eleftheriou and 1. Tsekos, Botanical Inst., Univ. of Thessaloniki, GR 54006 Thessaloniki,... more
... The results are discussed in relation with other plant glands, especially with the closely related Abutilon nectaries. Th. Sawidis, E. P. Eleftheriou and 1. Tsekos, Botanical Inst., Univ. of Thessaloniki, GR 54006 Thessaloniki, Greece. ...
Research Interests:
ABSTRACT The morpho-anatomy and histochemistry of the hysteranthous leaf ofUrginea maritima (L.) Baker and its adaptive strategies to the Mediterranean climate were investigated. The leaf ofU. maritima is 714 μm thick and possesses... more
ABSTRACT The morpho-anatomy and histochemistry of the hysteranthous leaf ofUrginea maritima (L.) Baker and its adaptive strategies to the Mediterranean climate were investigated. The leaf ofU. maritima is 714 μm thick and possesses moderate specific leaf mass (8.564 mg cm-2) and low tissue density (136.5 mg cm-3). The epidermal cells are compactly arranged and covered with cuticle. The average density of stomata in lower epidermis is higher than that of the upper one. The mesophyll cells occupy 52.96% of the total volume of the leaf, while the mesophyll intercellular spaces and the air spaces occupy 30.41%. Idioblastic cells containing raphide bundles and different phenotypes of crystalloid inclusions, embedded in polysaccharides, occur in the lower side of the mesophyll. The presence of oil droplets and lipids is evident. Bundle sheath cells are hardly visible with no chloroplasts which are a pronounced C3 plant character. Plastids containing protein crystalloid inclusions are abundant in the protophloem sieve elements.U. maritima, a deciduous plant, possesses leaves with mesophytic characters, in order to optimize its adaptation to the seasonal fluctuation of environmental conditions of the Mediterranean climate.
Research Interests:
Research Interests:
ABSTRACT Multicellular long-stalked glandular hairs of the outer involucral bracts of Sigesbeckia jorullensis Kunth were investigated with transmission electron microscopy. The apical layer of head cells was characterized by many... more
ABSTRACT Multicellular long-stalked glandular hairs of the outer involucral bracts of Sigesbeckia jorullensis Kunth were investigated with transmission electron microscopy. The apical layer of head cells was characterized by many irregular leucoplasts, a well developed and in the secretory phase mostly agranular endoplasmic reticulum, few dictyosomes, and one calcium oxalate crystal per cell. The prevalent part of the secretion seems to originate from leucoplasts of apical head cells and is secreted into a subcuticular space after crossing cytoplasm and the plasma membrane. The sheath of this sub-cuticular space was formed exclusively by a thin cuticle, which was detached from the cell wall in the secretory phase. Some small wall protuberances were found between the sub-apical and apical cell layer. Whether the three to six layers of sub-apical head cells, containing many chloroplasts, contribute to the biogenesis of the lipophilic secretion or not, remains unclear. Light microscopy demonstrated that there was a small girdle bordering the subcuticular space, where the cuticle was firmly fixed to the cell wall. Analysis with EM did not reveal alterations in cell wall ultrastructure, which might cause the firm attachment of the cuticle to the cell wall along a girdle.
Research Interests:
Radiometric determination of natural Ra, Ra, K and artificial Cs radionuclides distribution have been performed over the Kozani-Ptolemïda-Amynteon basin (Western Macedonia). Here there are localized four lignite power plants, accounting... more
Radiometric determination of natural Ra, Ra, K and artificial Cs radionuclides distribution have been performed over the Kozani-Ptolemïda-Amynteon basin (Western Macedonia). Here there are localized four lignite power plants, accounting for about 70% of the total production of Greece's electricity. Soil samples, 0 to 20 cm depths, from both uncultivated and cultivated soils have been investigated. No significant increase in
Research Interests:
The distribution of natural K, Ra and Ra and artificial Cs has been investigated in nonvascular mosses (9 species) and lichens (10 species) and vascular gymnosperm (1 species), angiosperm trees and shrubs (3 species) over the... more
The distribution of natural K, Ra and Ra and artificial Cs has been investigated in nonvascular mosses (9 species) and lichens (10 species) and vascular gymnosperm (1 species), angiosperm trees and shrubs (3 species) over the Kozani-Ptolemaïda-Amynteon lignite basin in West Macedonia, Greece. Four lignite power plants producing about 70% of the electric energy of the country are to be found in this region. Both specific activity and transfer factors of these radionuclides have been determined by means of experiments. This study indicates that with regard to Ra and Cs, nonvascular lichens and mosses have a much higher transfer factor (2.27 for Ra and 43.77 Cs) compared with vascular plants (0.17 for Ra and 0.03 Cs), but a lower one for natural K (0.493 for lichens and mosses and respectively 1.190 for vascular plants). Compared with unpolluted areas (0.25 Bq/kg), the Ra specific activity in lichens and mosses was systematically higher (26.43 and 56.74 Bq/kg respectively).