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51.
Aircraft de-icing fluids (ADF) are a source of water and soil pollution in airport sites. Propylene glycol (PG) is a main component in several commercial formulations of ADFs. Even though PG is biodegradable in soil, seasonal overloads may result in occasional groundwater contamination. Feasibility studies for the biostimulation of PG degradation in soil have been carried out in soil slurries, soil microcosms and enrichment cultures with and without the addition of nutrients (N and P sources, oligoelements), alternative electron acceptors (nitrate, oxygen releasing compounds) and adsorbents (activated carbon). Soil samples have been taken from the contaminated area of Gardermoen Airport Oslo. Under aerobic conditions and in the absence of added nutrients, no or scarce biomass growth is observed and PG degradation occurs by maintenance metabolism at constant removal rate by the original population of PG degraders. With the addition of nutrient, biomass exponential growth enhances aerobic PG degradation also at low temperatures (4 ° C) that occur at the high season of snowmelt. Anaerobic PG degradation without added nutrients still proceeds at constant rate (i.e. no biomass growth) and gives rise to reduced fermentation product (propionic acid, reduced Fe and Mn, methane). The addition of nitrate does not promote biomass growth but allows full PG mineralization without reduced by-products. Further exploitation on the field is necessary to fully evaluate the effect of oxygen releasing compounds and adsorbents.  相似文献   
52.
In recent years, new tools for funding nature conservation have been designed. Because poverty is often significant in areas with high biodiversity, the improvement of local livelihoods is frequently considered as a secondary goal of new financing mechanisms besides nature conservation. The buffer zone of the Podocarpus National Park in Ecuador is such a high biodiversity zone. In this paper, we compare the cost-effectiveness and development potential of three different mechanisms to finance nature conservation implemented in this buffer zone, namely (a) an organic coffee label, (b) the Socio Bosque Program, a nationwide payment scheme for private forest conservation, and (c) FORAGUA, a regional water fund. This paper describes the functioning and the scope of the mechanisms and analyses their environmental and socio-economic impacts which are compared to the total costs. Results show that the water fund has the highest additionality in ecosystem service provision, while the payment scheme is the most cost-effective both for current as for increased ecosystem service provision and for extra rural job creation. Organic coffee certification has the highest positive impact on rural income creation.  相似文献   
53.
The variability of biological data is a main constraint affecting the quality and reliability of lichen biomonitoring surveys for estimation of the effects of atmospheric pollution. Although most epiphytic lichen bioindication surveys focus on between-site differences at the landscape level, associated with the large scale effects of atmospheric pollution, current protocols are based on multilevel sampling, thus adding further sources of variation and affecting the error budget. We test the hypothesis that assemblages of lichen communities vary at each spatial scale examined, in order to determine what scales should be included in future monitoring studies. We compared four sites in Italy, along gradients of atmospheric pollution and climate, to test the partitioning of the variance components of lichen diversity across spatial scales (from trunks to landscapes). Despite environmental heterogeneity, we observed comparable spatial variance. However, residuals often overcame between-plot variability, leading to biased estimation of atmospheric pollution effects.  相似文献   
54.
The Antley-Bixler syndrome is characterized by multiple skeletal fusions including humero-radial synostosis, anterior bowing of the femora, cardiac and renal malformations and a high incidence of early postnatal lethality. In the pregnancy of a mother who had previously given birth to a child with the Antley-Bixler syndrome, prenatal ultrasound diagnosis was performed at 17 and 20 weeks. Fixed flexion of about 80° in both elbows was seen together with humero-radial synostosis and bowing of the ulnae. The fetus performed jerky cranio-caudal movements in its shoulders, but did not, during five hours of real-time observation, move at all in the elbows. Mild anterior bowing of the femora was also observed. The pregnancy was terminated at 21 weeks, and radiological examination of the female fetus confirmed the above mentioned findings including complete bilateral humero-radial synostosis. She also had cardiac and renal malformations. An ultrasound diagnosis of syndromes which have humero-radial synostosis as one feature is possible. Immobility and flexion in the elbows during a long period is probably the essential diagnostic finding.  相似文献   
55.
Iero A  Manente S  Perin G  Bragadin M 《Chemosphere》2003,52(7):1115-1123
A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at -22 degrees C, instead of -80 degrees C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark electrode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen consumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excel Macro, identified the break-point in the oxygen consumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests.  相似文献   
56.
GOAL, SCOPE AND BACKGROUND: Malodorous volatiles derived from the decomposition of biowaste within the process of composting might pose a risk to human health. Different techniques of process engineering have been developed to minimise the burden of malodorous compounds in air possibly affecting compost workers and residents in the vicinity. METHODS: In the present study, three different composting facilities were examined for the emission of volatiles to estimate the impact of process engineering on the dispersal of odorous compounds and to discuss its relevance for human health. RESULTS AND DISCUSSION: Concentrations of single compounds belonging to alcohols, ketones, furanes, sulfur-containing compounds and especially terpenes ranged from 10(2) up to nearly 10(6) ng/m3 depending on the sampling sites and the process engineering. The ratio of MVOC and total VOC measured changed throughout the process of biodegradation. A certain combination of volatile compounds coincided with the occurrence of typical compost odour. CONCLUSION: The type of process engineering seemed to have a major impact on the emission of volatiles, as amounts of (microbial) volatiles emitted were characteristic for the different techniques used. Thus, the MVOC emission basically depends on the degree of biodegradation. It is likely that the concentrations workers are exposed to can have an impact on human health. RECOMMENDATIONS AND OUTLOOK: It is obvious that less sophisticated types of process engineering give rise to greater amounts of bioaerosols and volatiles and, therefore, technical devices have to be improved and controlled regularly to minimise adverse health effects on workers.  相似文献   
57.
Polycyclic aromatic hydrocarbons (PAHs) and dioxins are lipophilic organic pollutants occurring widely in the terrestrial environment. In order to study the PAHs and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) transfer in the food chain, pigs have been fed with milk mixed either with 14C-phenanthrene, with 14C-benzo[a]pyrene or with 14C-TCDD. The analysis of portal and arterial blood radioactivity showed that both PAHs and TCDD were absorbed with a maximum concentration at 4-6 h after milk ingestion. Then, the blood radioactivity decreased to reach background levels 24 h after milk ingestion. Furthermore, the portal and arterial blood radioactivities were higher for phenanthrene (even if the injected load was the lowest) than these of benzo[a]pyrene or these of TCDD, in agreement with their lipophilicity and water solubility difference. Main 14C absorption occurred during the 1-3 h time period after ingestion for 14C-phenanthrene and during the 3-6 h time period for 14C-benzo[a]pyrene and for 14C-TCDD. 14C portal absorption rate was high for 14C-phenanthrene (95%), it was close to 33% for 14C-benzo[a]pyrene and very low for 14C-TCDD (9%). These results indicate that the three studied molecules have a quite different behaviour during digestion and absorption. Phenanthrene is greatly absorbed and its absorption occurs via the blood system, whereas benzo[a]pyrene and TCDD are partly and weakly absorbed respectively. However these two molecules are mainly absorbed via the portal vein.  相似文献   
58.
The Science of Nature - Female-only colour polymorphism is rare in birds, but occurs in brood parasitic cuckoos (Cuculidae). Obligate brood parasites leave incubation and parental care to other...  相似文献   
59.
Toxicity attenuation of olive mill wastewater in soil slurries   总被引:1,自引:0,他引:1  
Olive mill wastewaters are toxic for plants and microbes due to their high polyphenol content. We studied the effect of agricultural soil as a natural catalyst to promote polyphenol oxidation and polymerization, and in turn detoxify olive mill wastewaters. We show that model polyphenols are fully converted in soil slurries. Their products show no toxicity to the growth of a typical soil bacterium, Bacillus cereus, and reduced phytotoxicity in germination tests with English cress seeds. Those findings are promising for the sustainable treatment of olive wastewater in aerated soil slurries.  相似文献   
60.
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