In all tanning technology operations wastes are generated. These reach the environment as residual waters, solid and liquid waste as well as atmospheric emissions and odours.
This study tests an alternative method to the traditional tanning method at an industrial level. The new method is based on tanning without float and by significantly increasing the temperature at the end of the tanning process. The properties of the leathers obtained using the two methods have been compared and the results indicate that those leathers have similar physical, chemical, and organoleptic properties. However, the differences existing from the environmental point of view are significant. It is not necessary to use clean water for this tanning. Moreover, there is a 75% reduction of the residual float, a 91% reduction of the chrome discharged, and a 94% reduction of the chlorides discharged. A financial assessment was carried out to demonstrate that the newly proposed system is 32% more economic than the traditional one. 相似文献
Feral carp were collected at two Spanish rivers, Anoia and Cardener, showing PBDE levels from 29 to 638 ng/g lipid weight (lw) and from 54 to 744 ng/g lw, respectively. Sediments were also collected, showing PBDE contamination between 2 and 10 ng/g dry weight (dw). Differences in PBDE profiles between sediments and fish were noticed. Contribution of BDE-47 in sediment was up to 11%, whereas it contributed 37-90% of PBDEs in fish. Similar results were observed for BDE-154, which was only detected in one sediment sample, but presented high contribution in carp. In contrast, BDE-99 contributed up to 32% in sediments, but it was not detected in fish. Similar results were observed for BDE-153, BDE-183 and BDE-209. The main reason for their concentration decrease or absence in biota may be due to low bioavailability potential or due to biotransformation processes. 相似文献
The ‘scope for growth’ (SFG) tool was used to study the growth performance of cultivated populations of Mytilus galloprovincialis (Lmk., 1819) in an oligotrophic area of the Southern Mediterranean Sea. The study was carried out between 1993 and 1996 by
using data from four seasonal oceanographic cruises and from growth experiments. Water samples were collected and analysed
for total suspended matter (TSM), particulate organic carbon (POC) and nitrogen (PON), particulate lipids, proteins and carbohydrates
and chloropigments. The sum of the carbon equivalents of carbohydrates, proteins and lipids is indicated as the total biopolymeric
particulate organic carbon (BPC) and was converted into a unit of energy in order to calculate the SFG of a theoretical mussel
of 5 cm length. In order to test the performance of mussel growth at two depths (5 and 15 m water depth), mussel body size
[as ash free dry weight (AFDW)] and the actual concentrations of BPC were used to calculate the monthly SFG using the physiological
energetic relationships suggested in the current literature. Data from the field cruises led us to characterise the study
site as ultra-oligotrophic (annual average of chloropigment concentration approximately 0.5 μg L−1). SFG calculations allowed us to identify a site where mussels grown successively were found to reach a commercial size in
approximately 12 months. The good agreement obtained between energetic response and subsequent production response suggests
that the available energy from particulate food could be fully available for organic production for maintaining “proportionate”
growth trajectories, even in a ultra-oligotrophic system. 相似文献
Forest fires are an integral part of the ecology of the Mediterranean Basin; however, fire incidence has increased dramatically during the past decades and fire is expected to become more prevalent in the future due to climate change. Fuel modification by prescribed burning reduces the spread and intensity potential of subsequent wildfires. We used the most recently published data to calculate the average annual wildfire CO(2) emissions in France, Greece, Italy, Portugal and Spain following the IPCC guidelines. The effect of prescribed burning on emissions was calculated for four scenarios of prescribed burning effectiveness based on data from Portugal. Results show that prescribed burning could have a considerable effect on the carbon balance of the land use, land-use change and forestry (LULUCF) sector in Mediterranean countries. However, uncertainty in emission estimates remains large, and more accurate data is needed, especially regarding fuel load and fuel consumption in different vegetation types and fuel layers and the total area protected from wildfire per unit area treated by prescribed burning, i.e. the leverage of prescribed burning. 相似文献
In a previous article, Beschta et al. (Environ Manag 51(2):474–491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO2 and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20–50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing. 相似文献
The urinary excretion of t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (SPMA) and urinary benzene and the influence of a smoking habit and of exposure to urban traffic on the urinary excretion of these biomarkers were investigated in 137 male adults from the general population. All subjects were not occupationally exposed to benzene and resident in two cities in Puglia (Southern-Italy). Environmental exposure to benzene was measured using passive personal samplers. The biomarkers t,t-MA, SPMA and urinary benzene were determined in urine samples collected from each subject at the end of the environmental sampling. The percentage of cases above the limit of detection was higher for SPMA and urinary benzene in smokers than in non-smokers, and for airborne benzene and urinary benzene in subjects exposed to urban traffic. Airborne benzene was correlated with the time spent in urban traffic during the environmental sampling. Among the biomarkers, urinary benzene was found to be correlated with airborne benzene only in non-smokers, and with the time spent in urban traffic, both in smokers and non-smokers considered together, and in non-smokers only. Finally, multiple regression analysis showed that the urinary excretion of all the biomarkers was dependent on the number of cigarettes smoked per day and, for urinary benzene, also on the time spent in urban traffic. In conclusion, urinary benzene seems to be a more valid biomarker than t,t-MA and SPMA to assess environmental exposure to extremely low concentrations of benzene. Cigarette smoking prevailed over traffic exhaust fumes in determining the internal dose of benzene. 相似文献
The sustainability concept applied to human activities implies the need to harmonise the protection of environment with a satisfactory economic and social development. This is particularly true for tourism development: a misuse of the natural resources can cause a degradation of the tourist appeal of the destination, bringing it finally to its economic decline. This problem is particularly important in coastal tourism destinations. The implementation of an environmental management system is a powerful way for progressing towards better environmental performances. In this paper, the main results obtained in applying the Eco-Management and Audit Scheme procedure to the municipality of Cervia, a well-known tourist destination located on the Adriatic coast of Italy are described. This research puts into evidence that the main environmental pressures in the summer season are related to the supply of potable water, the production of solid wastes and wastewater air pollution and noise, etc. However, if correctly planned and managed, tourism can also contribute to environmental protection, to the conservation of biodiversity and to a sustainable use of natural resources. 相似文献