Journal of Material Cycles and Waste Management - Palladium finds a remarkable use in electronic devices and catalysts; therefore, an efficient and complete recovery from the containing secondary... 相似文献
Sustainable development of coastal zones must balance economic development that encourages human visitation from a larger population with desires that differ from the local residents with the need to maintain opportunities for the local resident society and conserve ecological capital, which may serve as the basis for residents.We present a case study in which the sustainability level of a coastal zone (Riviera del Beigua), located along the Ligurian coast of north-western Italy, was assessed through the lens of systems ecology using emergy synthesis to integrate across economic, social and environmental sub-systems.Our purposes were (1) to quantify the environmental sustainability level of this coastal zone, (2) to evaluate the role of tourism in affecting the economy, society and environment, and (3) to compare emergy synthesis to Butler's Tourism Area Life Cycle model (TALC). Results showed that 81% of the total emergy consumption in the coastal zone was derived from external sources, indicating that this tourist-heavy community was not sustainable. Tourism, as the dominant economic sub-system, consumed 42% of the total emergy budget, while local residents used the remaining 58%. The progressive stages of the TALC model were found to parallel the dynamic changes in the ratio of external emergy inputs to local emergy inputs, suggesting that emergy synthesis could be a useful tool for detecting a tourist region's TALC stage. Use of such a quantitative tool could expedite sustainability assessment to allow administrative managers to understand the complex relationship between a region's economy, environment and resident society so sound policies can be developed to improve overall sustainability. 相似文献
The concentrations of total, inorganic and organic carbon in the surface sediment of the central part of the Venice lagoon (31-55 stations) during the month of June in 1987, 1993 and 1998 were recorded. In two stations: San Giuliano and Lido, samples were collected on a monthly basis for 1 year also in different periods. On an average, by considering the whole central lagoon, inorganic carbon (IC) and total carbon (TC) did not show significant changes. In contrast organic carbon (OC) had alternating trends showing a decrease from 1987 to 1993, due to the almost complete disappearance of huge macroalgal biomasses, and a marked increase from 1993 to 1998, because of the high sediment disturbance caused by the catching of the clam Tapes philippinarum Adams & Reeve which had colonised the sediment free of macrophytes. The carbon changes monitored in the two stations studied on a seasonal basis during different years not only confirmed such results, but also enhanced the effects of fishing activities at Lido station and those depending on the disappearance of macroalgae at S. Giuliano. Moreover, this paper underlines the importance of seagrass beds. In fact in the areas colonised by those plants the percentage of fine sediments and organic matter is on the increase, while erosive processes are contrasted. 相似文献
This paper represents the first result of an active collaboration between the University of Sannio and the San Pio Hospital (Benevento, Italy), started in the 2018, that aims to a detailed mineralogical investigation of urinary stones of patients from Campania region. Herein, selected human bladder stones have been deeply characterized for clinical purposes and environmental biomonitoring, focusing on the importance to evaluate the concentration and distribution of undesired trace elements by means of microscopic techniques in the place of conventional wet chemical analyses. A rare bladder stone with a sea-urchin appearance, known as jackstone calculus, were also investigated (along with bladder stones made of uric acid and brushite) by means a comprehensive analytical approach, including Synchrotron X-ray Diffraction and Simultaneous Thermal Analyses. Main clinical assumptions were inferred according to the morpho-constitutional classification of bladder stones and information about patient’s medical history and lifestyle. In most of the analyzed uroliths, undesired trace elements such as copper, cadmium, lead, chromium, mercury and arsenic have been detected and generally attributable to environmental pollution or contaminated food. Simultaneous occurrence of selenium and mercury should denote a methylmercury detoxification process, probably leading to the formation of a very rare HgSe compound known as tiemannite.
Nanoparticles (NPs) contained in commercial products are released and enter into the aquatic ecosystem, posing serious possible risks to the environment and affecting the food chain. Therefore, investigating the potential toxicity of NPs on aquatic organisms has become an important issue. This study assessed the toxicity and trophic transfer of metal oxide NPs from marine microalgae (Cricosphaera elongata) to the larvae of the sea urchin Paracentrotus lividus. Larvae (24 h old) were fed on 2000 cell mL?1 48 h of microalgae contaminated with 5 mg L?1 of several metal oxide NPs (SiO2, SnO2, CeO2, Fe3O4) for 15 days. Larval viability and development were monitored from the 4-arm stage to the 8-arm pluteus stage. A significant decrease in survival was observed in larvae fed with microalgae exposed to SiO2 and CeO2 NPs. Abnormal development, characterised by skeletal degeneration and altered rudiment growth, was observed in all larvae fed with contaminated NP algae. Our findings revealed that SiO2 and CeO2 NPs exerted a toxic effect in the trophic interaction analysed, by reducing sea urchin larval viability, and all metal oxide NPs induced toxicological effects. In conclusion, metal oxide NPs may enter the food chain and become bioavailable for marine organisms, affecting their development. 相似文献