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Pigment changes in norway spruce induced by dust pollution Texte intégral
1997
MANDRE, MALLE | TUULMETS, LIIVI
The influence of alkaline dust pollution (pH of water solution of dust 12.3–12.7) from a cement plant (Kunda town, Estonia) on chlorophylls and carotenoids of the needles of 60–80 year old Norway spruce was studied on sample plots established at different distances from the emission source. The highest sensitivity to dust impact was measured in the content of Chl a, Chl b, carotenoids and elements regulating or participating in the biosynthesis of pigments (Mg, Fe, N, Mn).
Afficher plus [+] Moins [-]Hydrochemistry of the aquifers in the Rio las Avenidas basin, Pachuca, Hidalgo, Mexico Texte intégral
1997
Huizar Álvarez, Rafael
Groundwater in the Rio de las Avenidas sub-basin corresponds to the bicarbonate-sodium and bicarbonate-calcium hydrochemical facies, which result from the mineralization of water passing through alkaline rocks (andesites) which prevail in this basin. However, the presence of high concentrations of Na⁺ and K⁺ reveals the existence of an external inflow of these elements: the registered mean values are respectively 94.3 and 19.0 ppm, with the Tèllez and Tizayuca areas standing out with reported values of up to 142 ppm. As for the concentration of soluble water cations, we find in decreasing order: Na⁺, Ca²⁺, Mg²⁺, K⁺, along with the anions HCO₃ ⁻, Cl⁻, SO₄ ²⁻, CO₃ ⁻, which combine to form the NaHCO₃, NaCl, Ca(HCO₃)₂, MgSO₄ and KCl salts. The presence of biological contaminants, P and detergents in the groundwater indicates that it may have been contaminated by waste water. In addition to the contaminants mentioned above, large quantities of Pb, B, Zn, Fe, Mn, Cr, Co were detected and although Fe, Pb, Zn, B, and Mn are closely related to the local lithology, the high concentrations of these elements along with the occurrence of Co, Cr, Cd, and Ni confirm the gradual degradation of the aquifers in the sub-basin. The water temperature indicates the existence of low temperature thermal processes in the area.
Afficher plus [+] Moins [-]The seasonal changes of keratinolytic fungi in sediments of Catalonian Rivers (Spain) Texte intégral
1997
Ulfig, K. | Łukasik, W. | Guarro, J. | Cano, J. | Gené Badía, Joan | Vidal, P. | Figueras, M. J.
The Catalonian river sediments were found to be rich in keratinolytic fungi. The keratinolytic fungal populations showed clear seasonal changes in the river sediments. The main factors ‘regulating’ these populations in such habitat were temperature, dissolved oxygen concentration, pH, ammonium, nitrates, total fungal number, BOD₅, water poisons (cyanides, detergents, phenols), salinity and, presumably, strong insolation associated with low water levels. The last was probably of special importance in the deterioration of the fungal populations in the spring/summer season. A toxic effect on keratinolytic fungi in sediments was observed.Chrysosporium keratinophilum was found to be most resistant to industrial contaminants and salinity. Therefore, this species could be used as an indicator of water pollution.
Afficher plus [+] Moins [-]Variations in sulphur and nitrogen foliar concentration of deciduous and conifers vegetation in Slovakia Texte intégral
1997
Maňkovská, Blanka
The foliage contents of Sₜₒₜₐₗ and Nₜₒₜₐₗ were determined in 405 Permanent monitoring plots in four National Parks and sixteen Landscape Protection Areas and were compared with 1483 Permanent monitoring plots on Slovakia. The foliage content of S ranged from 0.72 to 6.77 g kg⁻¹ in hardwoods and from 0.98 to 4.3 g kg⁻¹ in softwoods. A critical increase was determined in one National Park and in four Landscape Protection Areas. The foliage content of N ranged from 9.7 to 48.7 g kg⁻¹ in softwoods, and from 7.8 to 51.4 g kg⁻¹ in hardwoods. An insufficient level of N was determined in one Landscape Protection Area and a critical increase in four Landscape Protection Areas. The sulphur to nitrogen ratio ranged from 0.08 to 0.176 in softwoods, and from 0.078 to 0.253 in hardwoods. The foliage surface on hitherto explored four National Parks and sixteen Landscape Protection Areas in network 4×4 km was covered by all categories of rigid fallout particles. Fly-ash from coal combustion were observed each of National Parks and Landscape Protection Areas by scanning electron microscopy. Mycelia and spore, mineral matters, sand and soil particles were present on all National Parks and Landscape Protection Areas. Particles derived from aluminium production were observed at three Landscape Protection Areas. Particles derived from cement production and from lime works were observed at two National Parks and six Landscape Protection Areas. Particles derived from ferrous metals industry were observed at each of National Parks and Landscape Protection Areas and particles typical for other technologies were present in three of National Parks and twelve Landscape Protection Areas.
Afficher plus [+] Moins [-]Increased cadmium availability to crops on a sewage-sludge amended soil Texte intégral
1997
Tichý, R. | Ný, V. | Kužel, S. | Kolář, L.
Analysis of spatial distribution of sewage-sludge born cadmium on the experimental plot revealed positive correlation of total cadmium and organic matter. Soil pH fluctuated randomly on the field. ‘Bioavailable’ concentrations, as determined by NH₄-acetate extraction, were closely correlated to the total cadmium levels, and only negligible effects of pH and/or organic matter fluctuations were recorded. Desorption model using modified Freundlich isotherm was applied to predict risks of cadmium solubilization at different conditions. Simulations revealed that the organic matter content within the ranges found at the experimental field cannot support a proper immobilization of cadmium at pH-range observed at the field. The phenomenon was explained by ineffective care for the soil in the past.
Afficher plus [+] Moins [-]highway stormwater runoff quality: development of surrogate parameter relationships Texte intégral
1997
Thomson, N. R. | McBean1, E. A. | Snodgrass, W. | Monstrenko, I. B.
The development of relationships for predicting the impact of highway stormwater runoff is described. The predictive relationships are regression-based equations reflecting variations in the magnitude of the constituents of interest. The objective is to identify a subset of constituents that can be used as surrogates for the remaining constituents as a means of decreasing the costs of collection and measurement of highway stormwater runoff quality data.The Minnesota highway stormwater quality database complied in the late 1970's and early 1980's is employed in identifying the set of surrogate parameters. The findings indicate that total suspended solids, total dissolved solids, total volatile solids, and total organic carbon are effective surrogate parameters for numerous metals, ionic species, and nutrients. The findings also indicated that the developed ionic species constituent relationships are portable, while the metal and nutrient constituent relationships were limited to urban sites with similar environmental conditions. The development of these relationships represents a step towards remediating and preventing the problem of nonpoint source highway pollution.
Afficher plus [+] Moins [-]Diagnosis of boron, fluorine, lead, nickel and zinc toxicity in citrus plantations in villarreal, spain Texte intégral
1997
Aucejo, Antonio | Ferrer, José | Gabaldón, Carmen | Marzal, Paula | Seco, Aurora
In the late 1980s, citrus plantations in the area of Villarreal (Spain) showed injuries similar to those previously reported for boron and fluorine toxicity. The area was affected by the disposal of industrial wastewater, mainly from ceramic industries. Conjunctive uses of surface water, groundwater and wastewater for irrigation had taken place. A survey was conducted at 25 orchards to assess leaves and soil for their boron, fluorine, lead, nickel and zinc contents. Wastewater and groundwater were also analyzed to corroborate the presence of these pollutants. The results showed that both boron and fluorine contents were greater than those reported as excess at the most part of the orchards included in the study. Heavy metals toxicity effects were not confirmed. Boron pollution was attributed to industrial wastewater spills and fluorine contamination from atmospheric pollution.
Afficher plus [+] Moins [-]Annual balances of hexachlorocyclohexanes, polychlorinated biphenyls and triazines in the German Bight
1997
Huhnerfuss, H. | Bester, K. | Landgraff, O. | Pohlmann, T. | Selke, K. (Institut fur Organische Chemie der Universitat Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg (Germany))
Fluxes and budgets of contaminants in the German Bight
1997
Sundermann, J. | Radach, G. (Zentrum fur Meeres-und Klimaforschung der Universitat Hamburg, Institut fur Meereskunde, 22529 Hamburg (Germany))
Metals, petroleum hydrocarbons and organochlorines in inshore sediments and waters of Mombasa, Kenya
1997
Williams, T.M. | Rees, J.G. | Ferguson, A. | Herd, R.A. | Kairu, K.K. | Yobe, A.C. (British Geological Survey, Keyworth, Nottingham (United Kingdom))