世界旅游组织对国际生态旅游年的展望

国际生态旅游年表明联合国认识到了生态旅游在社会和经济方面的重要性 . 联合国大会希望 让政府和国际社会注意到生态旅游对自然环境、生物多样性保护以及当地的社会和文化结构 的潜在影响 ( 正面的和负面的 ) . 世界旅游组织 ( WTO) 正在和联合国环境署 ( UNEP) 、其他 国际机构和地区机构及其成员国、会员和其他团体一起协调一系列活动 - - 作为国际生态旅 游年 ( IYE) 的准备以及在国际生态旅游年期间的活动 .     

Comparison the effects of bioaugmentation versus biostimulation on marine microbial community by PCR–DGGE: A mesocosm scale

In order to better understand the effects of biostimulation and bioaugmentation processes on a marine microbial community, three different mesocosm experiments were planned. Natural seawater(10.000 L) was artificially polluted with crude oil(1 L) and(1) inorganic nutrients(Biostimulating Mesocosm, BM),(2) inorganic nutrients and an inoculum of Alcanivorax borkumensis SK2(Single Bioaugmentation Mesocosm, SBM),(3) inorganic nutrients and inoculums of A. borkumensis SK2 and Thalassolituus oleivorans MIL-1(Consortium Bioaugmentation Mesocosm, CBM). During the experimental period(20 days), samples were taken from each mesocosm and the community structure was analyzed by PCR–DGGE. The 16 S r RNA gene DGGE banding patterns and sequence analysis demonstrated that biostimulation had the lowest effect on microbial biodiversity in the mesocosms; however, the biodiversity of the marine microbial community dramatically decreased in the CBM(Shannon index was 0.6 in T3). The community structures among the three mesocosms were also markedly different,and major bacteria derived from DGGE bands were related to uncultured Gamma Proteobacteria. The biodegradation results show that the Single Bioaugmentation Mesocosm(SBM) system had the highest percentage of degradation(95%) in comparison to the BM mesocosm(80%) and CBM(70%).     

Case study evidence that direct regulation remains the main driver of industrial pollution avoidance and may benefit operational efficiency

Environmental regulation is required to reduce industrial pollution to levels that are socially acceptable and economically efficient, but there is debate over the most efficient form of such regulation. Typically, a limited range of environmental and economic parameters are accounted for in the econometric studies that inform that debate. This paper integrates evidence from two separate studies to assess a broad range of parameters related to the efficiency of industrial environmental regulation. Questionnaire responses from 25 Italian manufacturers of building-chemicals and 28 Irish pharmaceutical manufacturers provided evidence on the environmental effectiveness and operational impacts of different regulatory instruments. Combined with extensive emissions data from Irish pharmaceutical manufacturers, survey results enabled a quantitative estimation of pollution avoidance specifically attributable to direct regulation. The monetised social benefit of avoided pollution was found to be equal to direct compliance costs. Chemical manufacturers in Italy and Ireland stated that direct regulation is a more important driver of industrial environmental performance than economic or voluntary regulation, and their responses indicated that direct compliance costs may be countered somewhat by stimulated operational improvements. It was concluded that direct regulation is an effective approach for multi-pollutant control in an industrial context, and that the efficiency of such regulation may be underestimated in studies that do not consider the full range of pollutants and operational effects.     

Explosion behavior of hydrogen–methane/air mixtures

The effects of enriching natural gas with hydrogen on local flame extinction, combustion instabilities and power output have been widely studied for both stationary and mobile systems. On the contrary, the issues of explosion safety for hydrogen–methane mixtures are still under investigation.In this work, experimental tests were performed in a 5 L closed cylindrical vessel for explosions of hydrogen–methane mixtures in stoichiometric air. Different compositions of hydrogen–methane were tested (from pure methane to pure hydrogen) at varying initial pressures (1, 3 and 6 bar).Results have allowed the quantification of the combined effects of both mixture composition (i.e., hydrogen content in the fuel) and initial pressure on maximum pressure, maximum rate of pressure rise and burning velocity. The measured burning velocities were also correlated by means of a Le Chatelier’s Rule-like formula. Good predictions have been obtained (at any initial pressure), except for mixtures with hydrogen molar content in the fuel higher than 50%.     

Impact of source segregation intensity of solid waste on fuel consumption and collection costs

Fuel consumption and collection costs of solid waste were evaluated by the aid of a simulation model for a given collection area of a medium-sized Italian city. Using the model it is possible to calculate time, collected waste and fuel consumption for a given waste collection route. Starting from the data for the current waste collection scenario with a Source Segregated (SS) intensity of 25%, all the main model error evaluated was ?1.2. SS intensity scenarios of 25%, 30%, 35% and 52% were simulated. Results showed an increase in the average fuel consumed by the collection vehicles that went from about 3.3 L/tonne for 25% SS intensity to about 3.8 L/tonne for a SS intensity of 52%. Direct collection costs, including crews and vehicle purchase, ranged from about 40 €/tonne to about 70 €/tonne, respectively, for 25% and 52% SS intensity. The increase in fuel consumption and collection costs depends on the density of the waste collected, on the collection vehicle compaction ratio and on the waste collection vehicle utilization factor (WCVUF). In particular a reduction of about 50% of the WCVUF can lead to an average increase of about 80% in fuel consumption and 100% in collection costs.     

Urban Mining: Quality and quantity of recyclable and recoverable material mechanically and physically extractable from residual waste

The mechanically sorted dry fraction (MSDF) and Fines (<20 mm) arising from the mechanical biological treatment of residual municipal solid waste (RMSW) contains respectively about 11% w/w each of recyclable and recoverable materials. Processing a large sample of MSDF in an existing full-scale mechanical sorting facility equipped with near infrared and 2-3 dimensional selectors led to the extraction of about 6% w/w of recyclables with respect to the RMSW weight. Maximum selection efficiency was achieved for metals, about 98% w/w, whereas it was lower for Waste Electrical and Electronic Equipment (WEEE), about 2% w/w. After a simulated lab scale soil washing treatment it was possible to extract about 2% w/w of inert exploitable substances recoverable as construction materials, with respect to the amount of RMSW. The passing curve showed that inert materials were mainly sand with a particle size ranging from 0.063 to 2 mm. Leaching tests showed quite low heavy metal concentrations with the exception of the particles retained by the 0.5 mm sieve. A minimum pollutant concentration was in the leachate from the 10 and 20 mm particle size fractions.     

Process development for recovery of copper and precious metals from waste printed circuit boards with emphasize on palladium and gold leaching and precipitation

A novel hydrometallurgical process was proposed for selective recovery of Cu, Ag, Au and Pd from waste printed circuit boards (PCBs). More than 99% of copper content was dissolved by using two consecutive sulfuric acid leaching steps in the presence of H₂O₂ as oxidizing agents. The solid residue of 2nd leaching step was treated by acidic thiourea in the presence of ferric iron as oxidizing agent and 85.76% Au and 71.36% Ag dissolution was achieved. The precipitation of Au and Ag from acidic thiourea leachate was investigated by using different amounts of sodium borohydride (SBH) as a reducing agent. The leaching of Pd and remained gold from the solid reside of 3rd leaching step was performed in NaClO-HCl-H₂O₂ leaching system and the effect of different parameters was investigated. The leaching of Pd and specially Au increased by increasing the NaClO concentration up to 10 V% and any further increasing the NaClO concentration has a negligible effect. The leaching of Pd and Au increased by increasing the HCl concentration from 2.5 to 5 M. The leaching of Pd and Au were endothermic and raising the temperature had a positive effect on leaching efficiency. The kinetics of Pd leaching was quite fast and after 30 min complete leaching of Pd was achieved, while the leaching of Au need a longer contact time. The best conditions for leaching of Pd and Au in NaClO-HCl-H₂O₂ leaching system were determined to be 5 M HCl, 1 V% H₂O₂, 10 V% NaClO at 336 K for 3 h with a solid/liquid ratio of 1/10. 100% of Pd and Au of what was in the chloride leachate were precipitated by using 2 g/L SBH. Finally, a process flow sheet for the recovery of Cu, Ag, Au and Pd from PCB was proposed.     

The effects of familiarity and gender on spatial representation

This paper reports a study of how familiarity and gender may influence the frames of reference used in memory to represent a real-world regularly shaped environment. Familiar and unfamiliar participants learned the locations of three triads of buildings by walking on a path which encircled each triad. Then they were shown with maps reproducing these triads at five different orientations (from 0° to 180°) and had to judge whether each triad represented correctly the relative positions between the buildings. Results showed that unfamiliar participants performed better when the orientation of triads was closer to the learning perspective (0° and 45°) and corresponded to front rather than to back positions. Instead, familiar participants showed a facilitation for triads oriented along orthogonal axes (0°–180°, 90°) and no difference between front and back positions. These findings suggested that locations of unfamiliar buildings were mentally represented in terms of egocentric frames of reference; instead, allocentric frames of reference defined by the environment were used when the environment was familiar. Finally, males were more accurate and faster than females, and this difference was particularly evident in participants unfamiliar with the environment.     

Mytilus galloprovincialis as bioindicator in embryotoxicity testing to evaluate sediment quality in the lagoon of Venice (Italy)

The possibility of using Mytilus galloprovincialis from natural populations of the lagoon of Venice in toxicity bioassays based on embryo development, according to international standard methods, was investigated. In order to valuate this method for the lagoon, iterative steps including evaluation of reproducibility, sensitivity and discriminatory capacity towards some pure substances and environmental samples were performed. Evaluation of sensitivity towards a reference toxicant (copper) evidenced good replicability and repeatability. Results showed that natural population is better than hatchery population for performing bioassays. Evaluation of applicability to elutriates revealed that the method is able to discriminate among sediments of the lagoon of Venice at different typologies and levels of contamination, showing an important effect for almost all study sites.     

Screening of POP pollution by AChE and EROD activities in Zebra mussels from the Italian Great Lakes

The increase of ethoxyresorufin dealkylation (EROD) and the inhibition of acetylcholinesterase (AChE) as biomarkers have been commonly used in vertebrates for the persistent organic pollutants (POPs) biomonitoring of aquatic environments, but very few studies have been performed for invertebrates. Previous researches demonstrated the interference due to some chemicals on EROD and AChE activities of the freshwater bivalve Zebra mussel (Dreissena polymorpha) in laboratory and field studies, showing its possible use for the screening of POP effects. We investigated the contamination of the Italian sub-alpine great lakes (Maggiore, Lugano, Como, Iseo, Garda) by the biomarker approach on Zebra mussel specimens collected at 17 sampling sites with different morphometric characteristics and anthropization levels. Results showed a homogeneous contamination of AChE inhibitors in Lake Garda, Maggiore, Como and Iseo with values ranging from 0.5 to 3 nmol/min/mg proteins and with an average inhibition of about 66% to controls. The planar compounds pollution, able to activate the EROD activity, seems higher in some sampling stations of Lake Garda, Como and Iseo (2-4 pmol/min/mg proteins) than that measured in Lake Lugano (1.5-3 pmol/min/mg proteins). On the contrary, the enzyme activity in Lake Maggiore showed an interesting opposite effect of AhR-binding compounds and trace metals. Finally, the possible use of Zebra mussel specimens maintained at laboratory conditions as controls against the selection of the less polluted sampling site is discussed.