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Overhauling health effects perspectives.
1988
Schwebach G.H. | Cafaro D. | Egan J. | Grimes M. | Michael G.
[Protective utilization of water and land in the Bistrica river basin [Montenegro, Yugoslavia]]
1998
Popovic, V. (Institut za zemljiste, Beograd (Yugoslavia)) | Ivanovic, S. | Ivanovic, S. | Petrovic, P.
In this paper, we are consider processing of soils erosion and his way on protection expoitation of water for population water supply, melioration's systems for irrigation and for strew of manger of the Lim river with the tug and suspend bank (Montenegro, Yugoslavia). We are given suggestions for protective utilization of agricultural and forest lands and the possibilities of water exploitation from Bistrica river (Montenegro, Yugoslavia). That is useful for fishing, irrigation, energetic, tourism and water supply. In this paper, you can meet some suggestions about exploitations of minerals and organic fertilizars that are not toxics and they not any influence on pollution of land and water.
Mostrar más [+] Menos [-]Plant responses to atmospheric CO2 enrichment with emphasis on roots and the rhizosphere
1994
Rogers, H.H. | Runion, G.B. | Krupa, S.V.
Empirical records provide incontestable evidence of global changes: foremost among these changes is the rising concentration of CO(2) in the earth's atmosphere. Plant growth is nearly always stimulated by elevation of CO(2). Photosynthesis increases, more plant biomass accumulates per unit of water consumed, and economic yield is enhanced. The profitable use of supplemental CO(2) over years of greenhouse practice points to the value of CO(2) for plant production. Plant responses to CO(2) are known to interact with other environmental factors, e.g. light, temperature, soil water, and humidity. Important stresses including drought, temperature, salinity, and air pollution have been shown to be ameliorated when CO(2) levels are elevated. In the agricultural context, the growing season has been shortened for some crops with the application of more CO(2); less water use has generally, but not always, been observed and is under further study; experimental studies have shown that economic yield for most crops increases by about 33% for a doubling of ambient CO(2) concentration. However, there are some reports of negligible or negative effects. Plant species respond differently to CO(2) enrichment, therefore, clearly competitive shifts within natural communities could occur. Though of less importance in managed agro-ecosystems, competition between crops and weeds could also be altered. Tissue composition can vary as CO(2) increases (e.g. higher C: N ratios) leading to changes in herbivory, but tests of crop products (consumed by man) from elevated CO(2) experiments have generally not revealed significant differences in their quality. However, any CO(2)-induced change in plant chemical or structural make-up could lead to alterations in the plant's interaction with any number of environmental factors-physicochemical or biological. Host-pathogen relationships, defense against physical stressors, and the capacity to overcome resource shortages could be impacted by rises in CO(2). Root biomass is known to increase but, with few exceptions, detailed studies of root growth and function are lacking. Potential enhancement of root growth could translate into greater rhizodeposition, which, in turn, could lead to shifts in the rhizosphere itself. Some of the direct effects of CO(2) on vegetation have been reasonably well-studied, but for others work has been inadequate. Among these neglected areas are plant roots and the rhizosphere. Therefore, experiments on root and rhizosphere response in plants grown in CO(2)-enriched atmospheres will be reviewed and, where possible, collectively integrated. To this will be added data which have recently been collected by us. Having looked at the available data base, we will offer a series of hypotheses which we consider as priority targets for future research.
Mostrar más [+] Menos [-]Growth, photosynthesis and UV-B absorbing compounds of Portuguese Barbela wheat exposed to ultraviolet-B radiation
1999
Correia, C.M. | Torres-Pereira, M.S. | Torres-Pereira, J.M.G. (Department of Biological and Environmental Engineering, University of Tras-os-Montes and Alto Douro, Apartado 202, 5000 Vila Real (Portugal))
The effects of prior exposure to sulphur dioxide and nitrogen dioxide on the water relations of timothy grass (Phleum pratense) under drought conditions
1990
Lucas, P.W. (Institute of Environmental and Biological Sciences, Division of Biological Sciences, Lancaster University, Lancaster LA1 4YQ (United Kingdom))
The individual and combined effects of ozone and simulated acid rain on growth, gas exchange rate and water-use efficiency of Pinus armandi Franch
1996
Shan YunFeng | Feng ZongWei | Izuta, T. | Aoki, M. | Totsuka, T. (United Graduate School, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183 (Japan))
Effects of ultraviolet-B radiation (UV-B) on growth and physiology of the dune grassland species Calamagrostis epigeios
1995
Tosserams, M. | Rozema, J. (Department of Ecology and Ecotoxicology, Faculty of Biology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands))
Phosphorus Removal from Eutrophic Waters with an Aluminium Hybrid Nanocomposite
2012
Oliveira, M. | Machado, A. V. | Nogueira, R.
An excess of phosphorus (P) is the most common cause of eutrophication of freshwater bodies. Thus, it is imperative to reduce the concentration of P to prevent harmful algal blooms. Moreover, recovery of P has been gaining importance because its natural source will be exhausted in the near future. Therefore, the present work investigated the removal and recovery of phosphate from water using a newly developed hybrid nanocomposite containing aluminium nanoparticles (HPN). The HPN-Pr removes 0.80 ± 0.01 mg P/g in a pH interval between 2.0 and 6.5. The adsorption mechanism was described by a Freundlich adsorption model. The material presented good selectivity for phosphate and can be regenerated using an HCl dilute solution. The factors that contribute most to the attractiveness of HPN-Pr as a phosphate sorbent are its moderate removal capacity, feasible production at industrial scale, reuse after regeneration and recovery of phosphate.
Mostrar más [+] Menos [-]Fate of Heavy Metals in an Urban Natural Wetland: The Nyabugogo Swamp (Rwanda)
2011
Sekomo, Christian B. | Nkuranga, Egide | Rousseau, Diederik P. L. | Lens, P. N. L. (Piet N. L)
The Nyabugogo natural wetland (Kigali City, Rwanda) receives all kinds of untreated wastewaters, including those from industrial areas. This study monitored heavy metal concentrations (Cd, Cr, Cu, Pb, and Zn) in all environmental compartments of the swamp: water and sediment, the dominant plant species Cyperus papyrus, and fish (Clarias sp. and Oreochromis sp.) and Oligochaetes. Cr, Cu, and Zn concentrations in the water were generally below the WHO (2008) drinking water standards, whereas Cd and Pb were consistently above these limits. Except Cd, all metal concentrations were below the threshold levels for irrigation. The highest metal accumulation occurred in the sediment with up to 4.2 mg/kg for Cd, 68 mg/kg for Cu, 58.3 mg/kg for Pb, and 188.0 mg/kg for Zn, followed by accumulation in the roots of C. papyrus with up to 4.2 mg/kg for Cd, 45.8 mg/kg for Cr, 29.7 mg/kg for Cu, and 56.1 mg/kg for Pb. Except Cu and Zn, other heavy metal (Cd, Cr, and Pb) concentrations were high in Clarias sp., Oreochromis sp., and Oligochaetes. Therefore, there is a human health concern for people using water and products from the swamp.
Mostrar más [+] Menos [-]Effect of Abiotic and Biotic Factors on the Photo-Induced Production of Dissolved Gaseous Mercury
2011
Oh, Sehee | Kim, Moon-Kyung | Lee, Young-Min | Zoh, Kyung-Duk
This study was conducted to evaluate the contribution of environmental factors such as solar radiation and dissolved organic matter (DOM) on the photo-induced dissolved gaseous mercury (DGM) production through laboratory experiments using field water samples collected from wetlands. DGM production was more significantly influenced by UVB intensity than UVA. DGM formation was also significantly affected by DOM chemical structure/composition rather than its concentration. Increasing NO3 − concentration limited DGM production, but photo-induced Hg oxidation stimulated by NO3 − would possibly occur when the NO3 − level is more than twice the DOC level. The addition of phosphorus into the field water samples induced a slight increase of DGM production; however, the addition of nitrogen decreased DGM formation, suggesting that an increase of limiting nutrients in water may promote biotic DGM production. Experiments using a Selenastrum capricornutum monoculture solution showed that cell density had a positive effect on DGM production. Moreover, the difference in DGM production between filtered and unfiltered samples showed that S. capricornutum significantly produced biotic DGM under UVA irradiation. Finally, our results imply that environmental factors such as light intensity, DOM sources, and site-specific microorganisms can significantly affect photo-induced Hg transformation.
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