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661.
The mill waste water holds a large amount of polyphenols, preventing the biodegradation processes because of their inhibitory action on microbial growth. Thus, its disposal represents an environmental problem for the great olive oil producing countries in the Mediterranean area. In this work, we present the preliminary results from the application of a photo-oxidative process on mill waste water to evaluate the organic matter degradation potential and the biodegradability of the treated residue. The total organic carbon is reduced up to 35% after 6 hours but the cost-effectiveness is unfavourable. In contrast, the aim of toxicity reduction is less expensive and shows good applicable chances; after 2 h, the polyphenols concentration drops by 60%.  相似文献   
662.
This paper derives the analytical solutions to multi-compartment indoor air quality models for predicting indoor air pollutant concentrations in the home and evaluates the solutions using experimental measurements in the rooms of a single-story residence. The model uses Laplace transform methods to solve the mass balance equations for two interconnected compartments, obtaining analytical solutions that can be applied without a computer. Environmental tobacco smoke (ETS) sources such as the cigarette typically emit pollutants for relatively short times (7-11 min) and are represented mathematically by a "rectangular" source emission time function, or approximated by a short-duration source called an "impulse" time function. Other time-varying indoor sources also can be represented by Laplace transforms. The two-compartment model is more complicated than the single-compartment model and has more parameters, including the cigarette or combustion source emission rate as a function of time, room volumes, compartmental air change rates, and interzonal air flow factors expressed as dimensionless ratios. This paper provides analytical solutions for the impulse, step (Heaviside), and rectangular source emission time functions. It evaluates the indoor model in an unoccupied two-bedroom home using cigars and cigarettes as sources with continuous measurements of carbon monoxide (CO), respirable suspended particles (RSP), and particulate polycyclic aromatic hydrocarbons (PPAH). Fine particle mass concentrations (RSP or PM3.5) are measured using real-time monitors. In our experiments, simultaneous measurements of concentrations at three heights in a bedroom confirm an important assumption of the model-spatial uniformity of mixing. The parameter values of the two-compartment model were obtained using a "grid search" optimization method, and the predicted solutions agreed well with the measured concentration time series in the rooms of the home. The door and window positions in each room had considerable effect on the pollutant concentrations observed in the home. Because of the small volumes and low air change rates of most homes, indoor pollutant concentrations from smoking activity in a home can be very high and can persist at measurable levels indoors for many hours.  相似文献   
663.
The maintenance of biodiversity by securing representative and well-connected habitat networks in managed landscapes requires a wise combination of protection, management, and restoration of habitats at several scales. We suggest that the integration of natural and social sciences in the form of "Two-dimensional gap analysis" is an efficient tool for the implementation of biodiversity policies. The tool links biologically relevant "horizontal" ecological issues with "vertical" issues related to institutions and other societal issues. Using forest biodiversity as an example, we illustrate how one can combine ecological and institutional aspects of biodiversity conservation, thus facilitating environmentally sustainable regional development. In particular, we use regional gap analysis for identification of focal forest types, habitat modelling for ascertaining the functional connectivity of "green infrastructures", as tools for the horizontal gap analysis. For the vertical dimension we suggest how the social sciences can be used for assessing the success in the implementation of biodiversity policies in real landscapes by identifying institutional obstacles while implementing policies. We argue that this interdisciplinary approach could be applied in a whole range of other environments including other terrestrial biota and aquatic ecosystems where functional habitat connectivity, nonlinear response to habitat loss and a multitude of economic and social interests co-occur in the same landscape.  相似文献   
664.
Goal and Scope In order to realize surface consolidation of Pentelic marble on the Acropolis monuments, we have collected the criteria that have to be fulfilled by the methods and materials without side effects on the marbles (and other stones). When the existing methods and materials did not satisfy the requirements (criteria), we invented new ones.Methods The criteria were collected from the literature, by thermodynamic and kinetic viewpoints, by laboratory experiments and in situ observations on monuments, both in Greece and in several countries in which the various methods and materials were applied. Concerning our method of ‘Inversion of sulfation’, performed by spraying a K2CO3 solution, its concentration and its temperature were controlled in order to have a total inversion (certified by liquid crystals) of gypsum back to CaCO3. For the new material of ours, ‘Reinforced Lime’, in order to eliminate the disadvantages of plain lime (low carbonation rate, low mechanical properties of CaCO3 formed, lack of carbonation in the bulk of lime), measurements of the rate of carbonation were performed in plain lime and in lime with a different CaCO3 concentration beforehand as well as in a different CO2 environments, using DTG and XRD to measure the rate of carbonation. The detachment (kg/cm2) of marble specimens stuck by lime in each case was also measured. A microscope was also used to measure the dimensions of the grain in each case as well as ammonium citrate and thymolphthalein to certify the depth of carbonation in each case. Part of the work was communicated in an international congress.Results A table with the criteria of the selection of the methods and materials for the consolidation of Pentelic marble surfaces (and other stones) was established. None of the employed methods and materials fulfilled the criteria. Only the ‘Inversion of gypsum ‘ and the ‘Reinforced Lime’ were adopted and applied to the Acropolis monuments and to other monuments in Greece and in several other countries.Recommendation and Outlook All criteria must be used for the selection of methods and materials for the consolidation of the monument surfaces. This is why we have already studied with the same procedures, methods and materials for restoration, surface cleaning and protection.  相似文献   
665.
The orthopteran insect Tetrix tenuicornis, collected from polluted and unpolluted areas, was used to study heavy metal accumulation and its impact on stress protein levels and on changes in the number and morphology of chromosomes in mitotic and meiotic cells. During two consecutive years, insects were collected from polluted areas of zinc-lead mine spoils near Boles?aw (Poland) and from unpolluted areas near Busko and Staszów (Poland). T. tenuicornis from the polluted area showed 1.5, 4.03, 4.32 and 41.73 times higher concentrations of copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd), respectively, than insects of the same species collected from unpolluted areas. Insects exposed to heavy metals showed only small changes, and rather a decrease in the concentration of constitutive and inducible heat shock proteins Hsp70, the level of which increases under stress conditions. A cytogenetic study of T. tenuicornis revealed intra-population anomalies in chromosome number and morphology in mitotic and meiotic cells and the presence of an additional B chromosome in germinal cells. In 50% of females collected from polluted areas, mosaic oogonial mitotic chromosome sets and diploid, hypo- or hypertetraploid, tetraploid, and octoploid chromosome numbers were detected. In turn, 14.6% of males showed a heterozygous deficiency of chromatin in L2 and M3 bivalents in addition to the presence of B chromosomes.  相似文献   
666.
Precipitation of highly insoluble metal sulfide minerals like acanthite (beta-Ag2S) or red cinnabar (HgS) is in principle an effective means to reduce metal availability and toxicity in contaminated soils. Unfortunately, experiments have shown that red cinnabar may be solubilized in the presence of dissolved organic matter or thiol ligands. To determine whether the same applies to acanthite, a laboratory synthesized beta-Ag2S mineral was incubated for up to 3 weeks in the presence of KNO3, dissolved humic acids, cysteine, methionine and thiosulfate. XPS analysis identified Ag2O (52%), Ag2SO4 (8%) and Ag2S (40%) on the particle surfaces. Ag was released into solution in the presence of KNO3 and methionine, presumably from mixed-oxidation surface layers. Contrary to earlier results with cinnabar, however, humic acids reduced Ag concentrations in solution by about 75%, and cysteine and thiosulfate, each containing a free -SH functional group, almost completely suppressed Ag release into solution.  相似文献   
667.
Péry AR  Mons R  Garric J 《Chemosphere》2005,59(2):247-253
Little is known about the differences between the species of the genus Chironomus relatively to their life cycle strategies. This knowledge is however crucial to fully understand the response of the Chironomus community to field perturbations. Here, we proposed to study four Chironomus species by using an energy-based model to describe growth, emergence and reproduction. We used data from the literature for two species (Chironomus plumosus and Chironomus tentans) and data from our experiments for two other species (Chironomus prasinus and Chironomus riparius). We showed that our model is able to accurately describe the life-history attributes for all the species tested, which suggests that Chironomus species have the same fundamental characteristics (low maintenance energetic costs, isomorphism), which makes possible the building of a common modelling framework to assess effects of toxicants at individual and population level. The species showed a few differences relatively to the parameters of the models with possible consequences when assessing effects of chemicals on Chironomus community. For instance, due to differences in growth parameters, C. riparius population dynamics should be more sensitive to effects on individual growth than C. prasinus or C. plumosus ones.  相似文献   
668.
Ground level ozone concentrations, in combination with the prevailing climate, at the estate Ostads S?teri in southwestern Sweden were estimated to reduce the yield of wheat and potato ranging between 5% and 10%. Occasionally, in years with the highest ozone concentrations and/or climatic conditions favoring high rates of ozone uptake to the leaves, yield loss levels above 10% may occur. Based on simple extrapolation, these ozone-induced reductions of crop yields at Ostads S?teri represent a potential total annual yield loss in Sweden in the range of 24.5 million Euro for wheat and 7.3 million Euro for potato, respectively. A simulation of forest growth at Ostad S?teri predicted that prevailing mean ozone exposure during 1993-2003 had the potential to reduce forest growth by 2.2% and the economic return of forest production by 2.6%. Using this value for extrapolation to the national level, the potential annual economic loss for Sweden due to negative impacts of ozone on forest production would be in the range of 56 million Euro (2004 prices).  相似文献   
669.
This study investigated the disease suppression abilities of a compost amendment that was added to the conventional growing medium, yellow cedar sawdust, used in most British Columbia vegetable greenhouses. The compost amendment was produced in a controlled, in-vessel process primarily from greenhouse crop waste materials. The pathogen and cultivar under study were Fusarium oxysporum f. sp. radicis-lycopersici (FORL) on Dombito (FORL-susceptible) beefsteak greenhouse tomatoes. Significant reduction of Fusarium crown and root rot was also realized in tomato seedlings by applying compost amendment from several different batches, as a seed cover or plug substitute. In a greenhouse trial, disease suppression using a mixture of 2:1 sawdust to amendment by volume was shown to be most effective. As a result, the tomato yield over a nine-month growing season was improved by 74% where the medium was deliberately infested with FORL.  相似文献   
670.
Phosphorus (P) is the limiting nutrient in freshwater primary production, and excessive levels cause premature eutrophication. P levels in aquaculture effluents are now tightly regulated. Increasing our understanding of waste P partitioning into soluble, particulate, and settleable fractions is important in the management of effluent P. When water supply is limited, dissolved oxygen concentration (DO) decreases below the optimum levels. Therefore, we studied effects of DO (6 and 10mg/L) and dietary P (0.7 and 1.0% P) on rainbow trout growth, P utilization, and effluent P partitioning. Biomass increased by 40% after 3 weeks. DO at 10mg/L significantly increased fish growth and feed efficiency, and increased the amount of P in the soluble fraction of the effluent. Soluble effluent P was greater in fish fed 1.0% P. DO increases fish growth and modulates P partitioning in aquaculture effluent.  相似文献   
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