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The aim of the work was the evaluation of the ability of individual PAHs from the US EPA list to migrate in relation to the sludge dose applied. On the basis of statistical analysis, an attempt was undertaken to evaluate the role of organic matter (total content of organic carbon) in the transportation of individual PAHs. Different doses of sewage sludge were introduced into the soil starting with a fertilizing dose (30 t·ha⁻¹), through melioration doses (75, 150, 300 t·ha⁻¹) to extreme doses (600 t·ha⁻¹). A few days after the application of sewage sludge, the increase of PAHs was noted in the 20-40 cm soil horizon. The range of increase depended on the sewage sludge dose applied. The highest increase in PAH content was observed in soil with a sludge dose of 300 t·ha⁻¹. However, after an 18-month period of study, the relationships observed before changed and the highest increase of individual PAHs in the 20-40 cm soil horizon relative to the control was noted in the case of the highest sludge dose.
Total petroleum hydrocarbons (TPHs) are one of the most common groups of persistent organic contaminants. Plant-based remediation is a relatively new, efficient and environmentally friendly technology that can be promising for removing many contaminants like hydrocarbon pollutants. The main objectives of the current research were to investigate the phytoremediation efficiency of burningbush, flax, and tall fescue as well as the influence of petroleum hydrocarbons on growth characteristics of these plant species. In order to improve soil condition and study the effect of fertilization on plant growth in oil-contaminated soil, peat fertilizer was applied in a separate treatment. Unfertilized as well as fertilized soil samples were analyzed for TPH removal by GC-FID in different time intervals. All plant species showed promising growth behaviour in highly contaminated soil. A decrease of TPHs was found over the course of the experiment in all treatments. The maximum removal was obtained in flax, in which flax removed 97.9% of the initial TPHs from soil. Results demonstrated that the three studied plant species were effective and promising in removing TPHs from contaminated, aged soil.
The aim of this study was to optimize storage conditions of a microbial community used for degradation of petroleum-derived environmental contaminants. Microorganisms were either freeze-dried or directly frozen (-20°C) in the presence of four stabilizers: trehalose, sucrose, glycerol and DMSO. It was found that preincubation with trehalose and sucrose had a positive impact on cell viability for both tested storage techniques. Disaccharide-stabilized consortia were more biodiverse than control samples (untreated with any protectants) and they retained high xenobiotic biodegradation capabilities. The effect of glycerol and DMSO was unexpectedly poor, contradicting other findings on the protective action of these compounds on monocultures. Higher cell survival was achieved only upon short-term (7 days) freezing, whereas DMSO proved to be lethal in the case of freeze-dried communities. Taking into account practical and economic reasons, the use of sucrose rather than the more expensive trehalose appears as the most efficient method for microbial consortia biostabilization during long-term storage. The experimental work provides some important data concerning the problem of elaboration of improved methods for preserving robust microbial communities to be used in environmental biotechnology practice.
Technical methods of purification of large areas of low and medium pollution are powerful, but extremely difficult to apply on a wide scale. This is due to high costs and the need to have specialised equipment during remediation. Phytoremediation is a much less complicated method. This environment cleaning technology uses the above-average capacity of some plant species to accumulate (socalled hyper-accumulation) or metabolise toxic chemicals. Soil microorganisms living in the rhizosphere also play an invaluable role in the degradation of harm-ful organic compounds; they are often much more involved in the mineralisation of xenobiotics than plants. Since plants provide favourable conditions for soil microorganisms to live – specific cooperation between them is possible. This kind of relationship can be useful in very effective removal of many toxic organic compounds, such as pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons and other petroleum compounds, from the soil. Although this process is relatively slow compared to other methods, its low invasiveness and economic considerations make it worthwhile. Currently, attempts at improvement of the natural process of phytoremediation using genetic engineering are undertaken more and more often. Among other things, genes encoding cytochromes from other organisms are implanted into the plant genome. This idea is constantly being developed and the results of research that is more and more widely conducted in this are promising.
The present study included an evaluation of the content of 16 PAH in sewage sludge produced in 15 sewage treatment plants in southeastern Poland. Besides determining PAH content, the influence of the amount and origin of the sewage purified in the PAH content was also evaluated. Possible PAH sources in sewage were also evaluated by the calculations of the mutual relations. The results obtained showed a clear differentiation in the content of polycyclic aromatic hydrocarbons. The content of the PAH sum ranged from 2039.9 to 36439.8 ^g/kg. The predominant contribution of 3 and 4-ring PAHs was observed. A significant relation was only found in the case of properties of the sludge puri­fied and the PAH content (-0.547, at P=0.05). Evaluating relations between individual PAHs, a statistically significant relation was observed between the sum of the PAHs determined and the content of fluoranthene, chrysene and benzo[b]fluoranthene.
We examine the composition and levels of organic contaminants (PAHs, PCB, HCB) in four sediment cores collected from the Barents Sea. We assess the influence of temporal variations in contaminant supplies and post-depositional reworking on contaminant distribution. Anthropogenic levels of P12PAH reached 95 ng g−1, higher inventories dominated by BKF were observed at southern stations, while northern stations exhibited lower inventories with PHE as the dominant compound. The PCB composition was similar at all stations dominated by CB101, 138 and 153. P7PCB concentrations were higher at northern stations. The observed composition and spatio-temporal pattern of organic contaminants is in accordance with long-range transport supplies.
This article discusses the topics and ideas presented at the Special Session of the conference Dioxin 2008 (28th International Symposium on Halogenated Environmental Organic Pollutants and POPs) titled: "Emerging POPs". The session was devoted to emerging and re-emerging compounds or groups of compounds identified recently as environmental contaminants and classified as dioxin-like compounds or persistent organic pollutants.
Polibromowane difenyloetery (PBDE) ze względu na swoje właściwości fizyko-chemiczne są zaliczane do grupy persystentnych zanieczyszczeń organicznych (POPs - Persystent Organie Pollutants). Charakteryzują się one dużą trwałością w środowisku i znaczną lipofilnością co może stanowić istotne zagrożenie dla zdrowia człowieka. Obecnie pozostałości tych związków stwierdza się we wszystkich elementach środowiska, w tym również w tkankach pochodzących od człowieka, na całym świecie. Najwyższe ich stężenia występują w próbkach pochodzących ze Stanów Zjednoczonych, co związane jest z powszechnością stosowania PBDE w tym kraju jako uniepalniaczy. Badania prowadzone w ostatnich latach dowodzą, że poziomy PBDE w próbkach środowiskowych zdecydowanie wzrosły. Kongenerami stwierdzanymi w najwyższych stężeniach są BDE-47, -99, -153, -209. Najnowsze szwedzkie dane wskazują jednak na możliwy spadek stężeń związków należących do tej grupy chemicznej co interpretowane jest jako konsekwencja wprowadzonych obostrzeń dotyczących ich stosowania i produkcji. Ponadto wykazano, że oddziałują one na układ nerwowy, dokrewny i immunologiczny, a pojawiają się również prace sugerujące związek między środowiskowym narażeniem na te związki wyrażonym wielkością ich tkankowych depozytów a ryzykiem zachorowania na niektóre rodzaje nowotworów. Dlatego też kontynuacja badań dotyczących występowania PBDE w środowisku oraz ich skutków toksykologicznych wydaje się uzasadniona.
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