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81.
C. Block B. Van Praet T. Windels I. Vermeulen G. Dangreau A. Overmeire E. D’Hooge T. Maes G. Van Eetvelde C. Vandecasteele 《Journal of Industrial Ecology》2011,15(4):584-596
The industrial park of Herdersbrug (Brugge, Flanders, Belgium) comprises 92 small and medium‐sized enterprises, a waste‐to‐energy incinerator, and a power plant (not included in the study) on its site. To study the carbon dioxide (CO2) neutrality of the park, we made a park‐wide inventory for 2007 of the CO2 emissions due to energy consumption (electricity and fossil fuel) and waste incineration, as well as an inventory of the existing renewable electricity and heat generation. The definition of CO2 neutrality in Flanders only considers CO2 released as a consequence of consumption or generation of electricity, not the CO2 emitted when fossil fuel is consumed for heat generation. To further decrease or avoid CO2 emissions, we project and evaluate measures to increase renewable energy generation. The 21 kilotons (kt) of CO2 emitted due to electricity consumption are more than compensated by the 25 kt of CO2 avoided by generation of renewable electricity. Herdersbrug Industrial Park is thus CO2 neutral, according to the definition of the Flemish government. Only a small fraction (6.6%) of the CO2 emitted as a consequence of fossil fuel consumption (heat generation) and waste incineration is compensated by existing and projected measures for renewable heat generation. Of the total CO2 emission (149 kt) due to energy consumption (electricity + heat generation) and waste incineration on the Herdersbrug Industrial Park in 2007, 70.5% is compensated by existing and projected renewable energy generated in the park. Forty‐seven percent of the yearly avoided CO2 corresponds to renewable energy generated from waste incineration and biomass fermentation. 相似文献
82.
Forest harvest residues are important raw materials for bioenergy in regions practicing forestry. Removing these residues from a harvest site reduces the carbon stock of the forest compared with conventional stem‐only harvest because less litter in left on the site. The indirect carbon dioxide (CO2) emission from producing bioenergy occur when carbon in the logging residues is emitted into the atmosphere at once through combustion, instead of being released little by little as a result of decomposition at the harvest sites. In this study (1) we introduce an approach to calculate this indirect emission from using logging residues for bioenergy production, and (2) estimate this emission at a typical target of harvest residue removal, i.e. boreal Norway spruce forest in Finland. The removal of stumps caused a larger indirect emission per unit of energy produced than the removal of branches because of a lower decomposition rate of the stumps. The indirect emission per unit of energy produced decreased with time since starting to collect the harvest residues as a result of decomposition at older harvest sites. During the 100 years of conducting this practice, the indirect emission from average‐sized branches (diameter 2 cm) decreased from 340 to 70 kg CO2 eq. MWh?1 and that from stumps (diameter 26 cm) from 340 to 160 kg CO2 eq. MWh?1. These emissions are an order of magnitude larger than the other emissions (collecting, transporting, etc.) from the bioenergy production chain. When the bioenergy production was started, the total emissions were comparable to fossil fuels. The practice had to be carried out for 22 (stumps) or four (branches) years until the total emissions dropped below the emissions of natural gas. Our results emphasize the importance of accounting for land‐use‐related indirect emissions to correctly estimate the efficiency of bioenergy in reducing CO2 emission into the atmosphere. 相似文献
83.
Benjamin D Hoffmann Lyn M Lowe Anthony D Griffiths 《Australian Journal of Entomology》2002,41(2):182-186
The impact of SO2 dry deposition from mining emissions on cricket abundance, diversity and composition was investigated at Mount Isa in the semiarid tropics of northern Australia. Seventy-one sites were sampled, stratified at two levels: sulphur deposition zones (high, medium, low, and background zones) and habitat (rocky ridge, rocky plain and alluvial plain). The three habitats did not support distinctly different cricket assemblages. Crickets responded to SO2 emissions, but impacts were largely restricted to the high-sulphur zone. Generalised linear modelling showed significant reductions in the probability of presence in the high-sulphur zone for the three genera Eurepella, Salmanites and Endacusta , and the subfamily Eneopterinae. In ordination space, the three high-sulphur zone by habitat combinations were clearly separated from all other combinations, and vector fitting of environmental variables showed soil SO4 to be a primary correlative factor of this separation. Crickets are sensitive to SO2 emissions and they appear to be a good indicator group in this context. 相似文献
84.
Down-regulation of light-saturated photosynthesis (Asat) at elevated atmospheric CO2 concentration, [CO2], has been demonstrated for many C3 species and is often associated with inability to utilize additional photosynthate and/or nitrogen limitation. In soybean, a nitrogen-fixing species, both limitations are less likely than in crops lacking an N-fixing symbiont. Prior studies have used controlled environment or field enclosures where the artificial environment can modify responses to [CO2]. A soybean free air [CO2] enrichment (FACE) facility has provided the first opportunity to analyze the effects of elevated [CO2] on photosynthesis under fully open-air conditions. Potential ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (Vc,max) and electron transport through photosystem II (Jmax) were determined from the responses of Asat to intercellular [CO2] (Ci) throughout two growing seasons. Mesophyll conductance to CO2 (gm) was determined from the responses of Asat and whole chain electron transport (J) to light. Elevated [CO2] increased Asat by 15–20% even though there was a small, statistically significant, decrease in Vc,max. This differs from previous studies in that Vc,max/Jmax decreased, inferring a shift in resource investment away from Rubisco. This raised the Ci at which the transition from Rubisco-limited to ribulose-1,5-bisphosphate regeneration-limited photosynthesis occurred. The decrease in Vc,max was not the result of a change in gm, which was unchanged by elevated [CO2]. This first analysis of limitations to soybean photosynthesis under fully open-air conditions reveals important differences to prior studies that have used enclosures to elevate [CO2], most significantly a smaller response of Asat and an apparent shift in resources away from Rubisco relative to capacity for electron transport.Abbreviations FACE Free air [CO2] enrichment - Rubisco Ribulose-1,5-bisphosphate carboxylase/oxygenase - RuBP Ribulose-1,5-bisphosphate - SoyFACE Soybean free air [CO2] enrichment - VPD Vapor pressure deficit 相似文献
85.
Reginald?Tan Hsien H.?KhooEmail author 《The International Journal of Life Cycle Assessment》2005,10(3):211-218
Aim, Scope and Background Metal die casting is a highly energy-intensive industry. In addition to that, the production of primary zinc by smelting consumes huge amounts of energy as well as generates many types of pollution. This paper uses LCA to investigate the environmental performance of a zinc cast product. The areas of environmental concern are focused on the direct and indirect air emissions that arise from the Zinc Smelting, Casting and Recycling, as well as transportation. Main Features The LCA case study employs a cradle-to-gate approach, which starts with the purchasing of primary zinc from abroad, casting, inspection, and ends when the scrap metal is sent back for recycling by truck. Based on a “generic” zinc casting product, the objective of the LCA was to compare the air emissions from the material cycle due to: i) the increased content of recycled metal in the final cast product; and ii) the choice of selecting between two Remelters (A and B), the first located near the company and the other in a neighbouring country, to send zinc scrap for recycling. The LCA SimaPro software (version 5.0) Eco-indicator “99 method is used to perform an impact assessment for Climate Change, Acidification, Ecotoxicity, Respiratory Inorganics, and Respiratory Organics was performed. Results The results from direct (process) and indirect (power plants) air emissions confirmed that the major air pollution occurs during Zinc Smelting, that is up to approximately 6570%. Although an increase in recycling rates resulted in higher levels of air pollution from transportation as well as heavy metals from dross, these two issues were insignificant compared to the huge amount of energy consumed for primary metal production. Based on air pollution from transportation alone, a significant reduction of greenhouse gases and VOCs of 90% each was appreciated when Remelter A was selected. Conclusion The results verified that efforts to recycle zinc and consume the material in a more sustainable manner have become highly important. Also, a second LCA investigation that was made to compare zinc cast products that consists of: 100% primary zinc, mixtures of 5050% and 4060% primary-to-recycled zinc, and finally 100% recycled zinc; further emphasized the need for using recycled metal, as opposed to using primary metal. 相似文献
86.
Seungdo?KimEmail author Bruce?DaleEmail author 《The International Journal of Life Cycle Assessment》2005,10(4):294-304
Goal and Scope This study estimates the life cycle inventory (LCI) of the electricity system in the United States, including the 10 NERC (North American Electric Reliability Council) regions, Alaska, Hawaii, off-grid non-utility plants and the US average figures. The greenhouse gas emissions associated with the United States electricity system are also estimated. Methods The fuel mix of the electricity system based on year 2000 data is used. The environmental burdens associated with raw material extraction, petroleum oil production and transportation for petroleum oil and natural gas to power plants are adopted from the DEAMTM LCA database. Coal transportation from a mining site to a power plant is specified with the data from the Energy Information Administration (EIA), which includes the mode of transportation as well as the distance traveled. The gate-to-gate environmental burdens associated with generating electricity from a fossil-fired power plant are obtained from the DEAMTM LCA database and the eGRID model developed by the United States Environmental Protection Agency. For nuclear power plants and hydroelectric power plants, the data from the DEAMTM LCA database are used.Results and Discussion Selected environmental profiles of the US electricity system are presented in the paper version, while the on-line version presents the whole LCI data. The overall US electricity system in the year 2000 released about 2,654 Tg CO2 eq. of greenhouse gas emissions based on 100-year global warming potentials with 193 g CO2 eq. MJe1 as an weighted average emission rate per one MJ electricity generated. Most greenhouse gases are released during combusting fossil fuels, accounting for 7895% of the total. The greenhouse gas emissions released from coal-fired power plants account for 81% of the total greenhouse gas emissions associated with electricity generation, and natural gas-fired power plants contribute about 16% of the total. The most significant regions for the total greenhouse gas emissions are the SERC (Southeastern Electric Reliability Council) and ECAR (East Central Area Reliability Coordination Agreement) regions, which account for 22% and 21% of the total, respectively. A sensitivity analysis on the generation and consumption based calculations indicates that the environmental profiles of electricity based on consumption are more uncertain than those based on generation unless exchange data from the same year are available because the exchange rates (region to region import and export of electricity) vary significantly from year to year.Conclusions and Outlook Those who are interested in the LCI data of the US electricity system can refer to the on-line version. When the inventory data presented in the on-line version are used in a life cycle assessment study, the distribution and transmission losses should be taken into account, which is about 9.5% of the net generation [1]. The comprehensive technical information presented in this study can be used in estimating the environmental burdens when new information on the regional fuel mix or the upstream processes is available. The exchange rates presented in this study also offer useful information in consequential LCI studies. 相似文献
87.
Spatial and temporal variation of atmospheric nitrogen deposition in the North China Plain
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A monitoring network of nine sites was established to determine the spatial and temporal variation of atmospheric nitrogen (N) deposition in the North China Plain (NCP) over a two-year period. The annual bulk deposition of inorganic N in the North China Plain ranged from 18.4 to 38.5 kg/hm2 and averaged 28.0 kg/hm2. The concentration of NH4 -N and NO3--N in rainwater averaged 3.76 and 1.85 mg/L, respectively, which were significantly higher than the values at background sites in China (normally less than 0.5 mg/L). Annual bulk deposition of inorganic N in the Beijing area (32.5 kg/hm2) was higher than that in Shandong and Hebei provinces (21.2 kg/hm2 on an average). Also bulk N deposition was much greater in Dongbeiwang and Fangshan than in Yanqing and Shunyi counties. Significant spatial variation of bulk deposition was observed in the Beijing area because of variation of precipitation, and 60% of bulk deposition occurred from June to September. Bulk deposition of NH4 -N was 2.0 times that of NO3--N deposition at the rural monitoring sites. However, the situation was reversed at the Beijing Academy of Agricultural-Forestry Sciences (BAAFS), the unique urban monitoring site. The results suggest that reduced N in precipitation is dominant in rural regions, but oxidized N is the major form in urban regions. The positive relationship between inorganic N deposition and precipitation can be fitted by a power equation (r2= 0.67), showing an increase of NH4 -N and NO3--N inputs with increased precipitation. Wet deposition of N accounted for 73% of the bulk deposition, implying that dry deposition of N, particularly NH4 -N from dust, is important in the North China Plain. 相似文献
88.
Effects of elevated atmospheric CO2 on soil enzyme activities at different nitrogen application treatments
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It has been predicted that elevated atmospheric CO2 will increase enzyme activity as a result of CO2-induced carbon entering the soil. The objective of this study was to investigate the effects of elevated atmospheric CO2 on soil enzyme activities under a rice/wheat rotation. This experiment was conducted in Wuxi, Jiangsu, China as part of the China FACE (Free Air Carbon Dioxide Enrichment) Project. Two atmospheric CO2 concentrations (580±60) and (380±40) μmol·mol-1) and three N application treatments (low-150, normal-250 and high-350 kg N·hm-2) were included. Soil samples (0-10 cm) were collected for analysis of β-glucosidase, invertase, urease, acid phosphates and β-glucosaminidase activities. The results revealed that with elevated atmospheric CO2 β-glucosidase activity significantly decreased (P < 0.05) at low N application rates; had no significant effect with a normal N application rate; and significantly increased (P < 0.05) with a high N application rate. For urease activity, at low and normal N application rates (but not high N application rate), elevated atmospheric CO2 significantly increased (P < 0.05) it. With acid phosphatase elevated atmospheric CO2 only had significant higher effects (P < 0.05) at high N application rates. Under different CO2 concentration, effects of N fertilization are also different. Soil β-glucosidase activity at ambient CO2 concentration decreased with N fertilization, while it increased at elevated CO2 concentration. In addition, invertase and acid phosphatase activities at elevated CO2 concentration, significantly increased (P < 0.05) with N treatments, but there was no effect with the ambient CO2 concentration. For urease activity, at ambient CO2 concentration, N fertilization increased it significantly (P < 0.05), whereas at elevated CO2 concentration it was not significant. Additionally, with β-glucosaminidase activity, there were no significant effects from N application. In general, then, elevated atmospheric CO2 increased soil enzyme activity, which may be attributed to the following two factors: (1) elevated atmospheric CO2 led to more plant biomass in the soil, which in turn stimulated soil microbial biomass and activity; and (2) elevated atmospheric CO2 increased plant photosynthesis, thereby increasing plant-derived soil enzymes. 相似文献
89.
90.
Airborne pollen sampling in Toledo, Central Spain 总被引:2,自引:0,他引:2
Herminia García-Mozo Rosa Pérez-Badia Federico Fernández-González Carmen Galán 《Aerobiologia》2006,22(1):55-66
Toledo is one of the main tourist spots of Spain, attracting around two million visitors per year. Its geographical situation
in the vast and scarcely monitored Region of Castilla La Mancha and the high number of tourists (especially in the spring)
has resulted in the Spanish Aerobiology Network (REA) making this city a major study objective. Air monitoring studies carried
out using REA sampling procedures commenced in October 2002. Thirty-two pollen types were identified during the sampling period
(October 2002 to October 2004). The annual Pollen Index (PI) was 44124 for the agricultural year October 2002–October 2003,
and 29666 in the same period of 2003–2004. The most abundant taxa were, in decreasing order of dominance: Cupressaceae, Quercus, Poaceae, Populus, Olea, Urticaceae, Platanus, Pinus and Ulmus. Other, less well-represented pollen taxa included Salix, Alnus, Fraxinus and Tamarix, which were characteristic of riverside areas, and Morus, Artemisia and Chenopodiaceae. The presence of Castanea pollen grains originating from chestnut crops far away from the city was clearly an example of long-distance transport. The
highest concentrations of airborne pollen were detected from March to May and also in January, due to the flowering of Cupressaceae
species. In general, there was a correlation between pollen and meteorological parameters: a positive correlation with temperature
and a negative correlation with rainfall and humidity during the pre-peak period. A negative correlation between temperature
and some tree pollen taxa was detected in the principal pollen period correlation analysis due to their long pollination periods. 相似文献