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The environmental pollution resulting from natural resources acquisition is one of the most severe problems nowadays. New environmental friendly and economically attractive techniques are proposed, using the ability of microorganisms (bioremediation) or plants (phytoremediation) for detoxification of their substrate. Depending on the type of pollutant and the mechanism of its immobilisation (accumulation or decomposition), several techniques are proposed. The specialised plant spe-cies are called hyperaccumulators, e.g. Brassica juncia, Helianthus annuus, Nicotiana tabacum or genetically modified Arabidopsis thaliana. Azolla caroliniana Willd. (Azollaceae) is an aquatic fern occurring in temperate and tropical climates. Recently, some natural stands of it were found in western Poland. The fern lives in symbiosis with cyanobacterium Anabaena azollae which is capable of fixing atmospheric nitrogen. Besides numerous application of Azolla in agriculture, e.g. as green manure, it was found that this plant possess a huge ability for phytoremediation. Our studies showed its ability for removal and accumulation of Hg, Cd, Pb, Cr, As, Ag, Pt and Au from waters (up to 100% of applied doses). These promising results open a new application of Azolla spp. for the purification of water polluted by heavy metals, for example as an additional step of wastewater purification.
Samples collected from different runoffs; AR, GMR, TR, ASR, and DR for aluminum roof, galvanized metal roof, thatch roof, asbestos roof and ambient rainfall respectively were analyzed for pH, conductivity, turbidity, TDS, TSS, NO3 -, PO4 3-, Cd, Cu, Fe, Zn and Pb. The result indicates that the mean concentration of the parameters analyzed ranged from 5.8± 0.39 –7.10±0.70, 22.25±11.70 -79.99± 3.40μScm-1, 1.47±0.43 - 46.53±1.60mg/l, 11.90±0.93 - 59.83±1.62NTU,15.53±0.70 - 204.53±5.08mg/l, 0.93±0.06 - 2.55±0.13 mg/l, 1.33±0.22 - 7.30±0.57mg/l respectively for pH, conductivity, TDS, turbidity, TSS, PO4 3- and NO3 -, and the levels of the heavy metals (in mg/l); Cd, Cu, Fe, Zn and Pb ranged from 0.0023±0.001– 0.0521±0.004, 0.052±0.01–0.2483±0.02, 0.0348±0.01–1.1120±0.07, 0.0161±0.01- 0.8093±0.02 and 0.0106±0.01- 0.0499±0.002 respectively. Ranking of the heavy metal in roof runoff is in the order; Fe>Zn>Cu>Cd>Pb. The result compared with WHO standard showed elevated level of the parameters analyzed with Cd and Pb exceeding the limit. Though the result of this study showed some variability which is an indication of the type of roofing material; air quality of the environment and industrial activity going on in the area. It could be deduced from the result that roof runoff may be a non point source of environmental pollution owning to the release of heavy metals and other pollutants into the environment, and increased concentration of some of the pollutants as reported by this study suggests that roof runoff water could impact negatively to the environment and if consumed without being treated may be injurious to human health.
A need for changing the curricula at chemical faculties of universities, to include proecological information into any and all specialised disciplines to a highest possible degree is becoming obvious. Proecological education is particularly important in the case of educating future chemists and chemical engineers. The general statements are illustrated by the example of the Chemical Faculty, Technical University of Gdańsk.
Ago-Iwoye –Ilisan road is the major road that links Abeokuta the state capital of Ogun –state to Ijebu towns. The road has always been experiencing pavement failure, which occurs inform of cracks and potholes. Being the major road, the effect of the failure has negative impact on the soicoeconomic growth of Ijebu –areas. The primary objective of the study was to determine the influence of the geotechnical properties of the sub-grade materials on the pavement performance of Ago- Iwoye – Ilishan Road. Eleven (11) soil samples were collected at eight (8) different locations with the aid of hand auger and were air-dried before taken to the laboratory for determination of engineering properties. The Liquid limit and the Plastic limits ranged from 13.9 – 46.2% and 8.1 – 32.7%, with the Plasticity index from 10.6 – 15.9% and Shrinkage limit from 6.2 – 27.7% respectively. The soaked CBR values of the subgrade materials is between 67% and 75% compared with 30% minimum specified by FMWH, 1997. The soils were classified by ASSHTO under the A-6 and A-7 category which shows that the soils are fair to poor as a sub-grade material and USCS classification shows that the soil falls into the SM and SC group. The comparison of all the results with the Nigeria specification (Federal Ministry of Works and Housing general guidelines) for the sub grade materials along the Ago-Iwoye- Ilisian road show that the materials underlain the pavement do satisfy the Nigeria standard. Therefore, the perennial failure frequently experience along the road route is not significantly influenced by subgrade materials. Hence, influence of other factors such as poor drainage courses, level of groundwater table, variation of geologic materials along the road route and poor construction materials should be thoroughly addressed before embarking on future rehabilitation of the highway.
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