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1.
中国啤酒生产的物质、能量消耗及环境影响分析   总被引:2,自引:0,他引:2  
李娜  胡聃  冯强 《生态学杂志》2008,27(8):1373
采用物质流分析方法,分析了2000-2005年中国啤酒行业物质、能源消耗趋势及环境负荷状况,并采用生命周期分析对中国啤酒生产的环境影响进行了评价.结果表明:2000-2005年,中国啤酒行业的物能消耗呈上升趋势,随着技术的进步,虽然生产1kL啤酒的污染物排放系数逐年下降,但全年总污染物排放量仍逐年上升;啤酒生产潜在的各类环境影响中以废水排放引起的富营养化最大;2000-2005年,中国啤酒行业各环境影响潜值(如富营养化、粉尘及烟尘、全球变暖、酸化、固体废弃物)均呈上升趋势,总环境影响潜值也逐年上升.推进啤酒工业生态转型,建设循环产业已势在必行.  相似文献   

2.
综合生命周期分析在可持续消费研究中的应用   总被引:7,自引:0,他引:7  
1992年联合国提出可持续消费的概念,经过10几年的发展,生命周期分析已经成为可持续消费的主要研究方法。由于传统生命周期分析方法需要大量基础数据支持,因此目前综合生命周期分析方法被广泛应用于可持续消费研究中。以1997年中国投入产出表为基础,建立了包括CO2排放量的投入产出表延长表。并对居民终端消费产生的CO2排放总量及其与产业部门的关系进行了分析。结果表明,1997年城市居民终端消费人均CO2排放量为1576.62kg,是农村居民CO2排放量的24.96倍,城市居民每个单位货币消费量所产生的CO2的排放量也远远高于农村居民,电力生产部门对居民消费环境影响的贡献率最大。对该方法中存在的一些问题进行了讨论,这些问题主要产生在价值量与物理量转换过程及分配过程中。  相似文献   

3.
广东省城市资源环境基尼系数   总被引:9,自引:1,他引:8  
广东省经济的快速发展与资源消耗、污染物排放是密切相关的,如何对资源消耗和污染物排放的公平性、合理性进行评价一直是个难题.构建资源环境基尼系数,用来评价广东省资源消耗和污染物排放的公平性、合理性.资源环境基尼系数是反映在经济贡献率相同的情况下,资源消耗、污染物排放公平程度的一个指标.选取广东省2005年能源消耗、COD排放、SO2排放和工业固体废物排放作为评价指标,计算其资源环境基尼系数,并以绿色贡献系数来判断资源消耗和污染物排放的不公平因子.结果表明,上述 4 项指标的资源环境基尼系数分别为 0.15,0.39,0.38,0.87.能源消耗处于绝对平均的范围内,COD和SO2排放处于相对合理的范围内,工业固废排放处于差距悬殊状态.广东省资源环境的分配差异较大,21个地市中,不公平因子主要集中在清远、韶关、云浮、河源这4个城市,而深圳、广州、中山3个城市体现出的是一种绿色发展模式.为缩小广东资源环境分配的空间差异,清远、韶关、云浮、河源等城市需要转变发展模式,实现经济与资源环境的协调发展.  相似文献   

4.
酶具有专一性与高效性,酶法工艺比传统工艺更节省原料和能源且应用广泛。以往对酶法工艺进行了大量的比较环境评估研究,以考查酶法工艺是否可以改善环境、促进清洁生产。总结并对环境评估的发展和技术实施提出建议。生命周期评估(LCA)作为一种评估工具被广泛使用,而"碳足迹"及环境影响评估(EIA)仅限于少数研究。全球气候变暖目前被视为一个评价指标,此外,一些研究也将其他影响因素视为评价指标。研究结果证实:酶法工艺替代传统工艺,可减少全球气候变暖、酸化、富营养化、光化学臭氧的形成和能源的消耗。酶法工艺能节省矿物燃料和无机化学原料。酶技术在促进工业清洁生产方面有着巨大的潜力。  相似文献   

5.
刘晶茹  刘瑞权  姚亮 《生态学报》2012,32(20):6553-6557
生产和消费是产生诸多环境问题的根本原因,而可持续生产和消费则是实现可持续发展的根本途径。基于产业生态学视角,界定了可持续消费的定义及内涵,认为可持续消费首先须符合代内公平、代际公平和资源能源永续合理利用等可持续理念;其次辨识了可持续消费研究依次经历关注消费者行为直接环境影响、关注产品和服务生命周期环境影响到关注消费者责任3个阶段;最后结合我国城市化、工业化背景,提出我国可持续消费研究应该以城市居民为重点、加强生命周期数据库建设和内注重可持续生产等建议。  相似文献   

6.
基于能值的污水处理系统环境影响分析   总被引:1,自引:0,他引:1  
污水处理厂及其“产物”(处理水和脱水污泥)的处理处置系统共同构成了污水处理综合系统,它从整体上涵盖了污水处理的全过程.污水处理综合系统在构建和运行的过程中主要包括两方面的环境影响:1)物质资源的消耗;2)排放污染物对环境的危害,而后者在既往有关的污水处理系统分析中往往被忽略.为了更全面地了解污水处理过程的环境影响状况,本文以能值分析理论为基础对污水处理综合系统进行分析,同时,结合生态足迹理论对系统的可持续性进行分析.结果表明:水体污染物的环境影响能值远大于大气污染物,且主要受氨氮排放量的影响;污水处理综合系统的能值消耗主要为废物流能值和本地可更新资源能值;“处理厂系统+填埋系统”的能值利用效率最高,“处理厂系统+中水回用系统+焚烧系统”的能值利用效率最低;“处理厂系统+中水回用系统+填埋系统”的环境可持续性最好,而“处理厂系统+焚烧系统”的可持续性最差.  相似文献   

7.
抗大豆疫霉根腐病野生大豆资源的初步筛选   总被引:9,自引:0,他引:9  
由大豆疫霉菌引起的大豆疫霉根腐病是严重影响大豆生产的毁灭性病害之一.防治该病唯一经济、有效和环境安全的方法是利用抗病品种.本研究对野生大豆资源进行抗大豆疫霉根腐病初步筛选,以期探讨野生大豆的抗性水平、分布和获得抗性野生大豆资源.通过苗期接种大豆疫霉菌对412份野生大豆资源进行抗病性鉴定,有13.4%的资源抗大豆疫霉根腐病,15.3%的资源表现为中间反应类型.对野生大豆资源的来源分析表明,抗大豆疫霉根腐病野生大豆资源在我国分布广泛,其中安徽省野生大豆资源抗性最丰富.  相似文献   

8.
基于生命周期的风电场碳排放核算   总被引:2,自引:0,他引:2  
戢时雨  高超  陈彬  李胜男 《生态学报》2016,36(4):915-923
风电是实现低碳战略的主力能源技术之一。为全面分析其对环境的影响,将自然植被纳入系统边界,计量风电场建设前后植被破坏及恢复带来的影响。在清单分析中,重点考虑对碳排影响较大的配件生产及运输、建设期工程车耗油排放,更加合理地核算风电场碳排放和量化其环境影响。核算结果表明:案例风电场全生命周期排碳量为2.97×104t C;运营期由于电能损耗造成的CO2排放量远大于其它阶段,占全过程的57.74%;整个过程中,能源消耗造成的碳排放远大于资源损耗排放。  相似文献   

9.
农业生态效率评价——以盆栽水稻实验为例   总被引:7,自引:1,他引:6  
吴小庆  徐阳春  陆根法 《生态学报》2009,29(5):2481-2488
农业面源污染已成为我国主要环境污染源,但目前缺乏一套针对农业生产的综合评价体系,作为对农业面源污染评估和监督的依据.根据生态效率理论,结合农业生产的特点,建立了综合考虑经济效益、资源物质消耗和环境影响的农业生态效率评价指标体系.以不同氮处理下(0.05、0.15、0.25 g N kg-1)不同水稻品种(锡稻11和武粳4)的盆栽实验为例,以氨挥发、肥料使用量和经济产量等数据为基础,运用基于层次分析法的TOPSIS法对6个评价对象的农业生态效率进行了评价和排序,分析各对象在经济效益、资源物质消耗和环境影响方面的差异与特点,指出施氮量和作物品种都对生态效率具有明显的影响.该评价体系的建立,将为我国农业生产模式从片面追求产量向经济、资源、环境协调可持续发展起到一定的推动作用.  相似文献   

10.
产业园区温室气体排放清单   总被引:3,自引:0,他引:3  
齐静  陈彬 《生态学报》2015,35(8):2750-2760
温室气体排放所导致的全球气候变化是国际社会长期关注的热点问题,它严重限制了人类社会的发展并威胁着人类的生存。产业园区通常集中了一个区域主要的生产要素与生产能力,也代表着特定产业在该区域的发展水平,理应作为发展低碳经济的基础单元和减少温室气体排放的重要控制点,也可以成为解决区域资源、环境问题的突破口。明确了产业园区温室气体排放的系统边界和内部结构,梳理了产业园区全生命周期温室气体排放行为,综合考虑产业园区能源消耗、工业生产、物质材料消耗、仪器设备投入、废弃物处理处置、景观绿化等过程,建立产业园区温室气体排放核算方法,并对案例园区进行了清单分析。结果表明:案例园区整个生命周期的温室气体排放量为1872177 t CO2-eq,其中运行管理阶段占全生命周期排放的比例最高,为95.35%。建设阶段的温室气体排放总量中建筑材料消耗引起的排放占到96.95%,主要集中在建筑工程、内部装修工程和外部装饰工程3个环节。运行管理阶段电力消耗、热力消耗和污水处理过程的排放量占到总量的98.69%。根据核算及分析结果提出了案例园区在建设和运行管理阶段实现温室气体减排的建议。  相似文献   

11.
LCA of soybean meal   总被引:2,自引:0,他引:2  
Background, Aim and Scope  Soybean meal is an important protein input to the European livestock production, with Argentina being an important supplier. The area cultivated with soybeans is still increasing globally, and so are the number of LCAs where the production of soybean meal forms part of the product chain. In recent years there has been increasing focus on how soybean production affects the environment. The purpose of the study was to estimate the environmental consequences of soybean meal consumption using a consequential LCA approach. The functional unit is ‘one kg of soybean meal produced in Argentina and delivered to Rotterdam Harbor’. Materials and Methods  Soybean meal has the co-product soybean oil. In this study, the consequential LCA method was applied, and co-product allocation was thereby avoided through system expansion. In this context, system expansion implies that the inputs and outputs are entirely ascribed to soybean meal, and the product system is subsequently expanded to include the avoided production of palm oil. Presently, the marginal vegetable oil on the world market is palm oil but, to be prepared for fluctuations in market demands, an alternative product system with rapeseed oil as the marginal vegetable oil has been established. EDIP97 (updated version 2.3) was used for LCIA and the following impact categories were included: Global warming, eutrophication, acidification, ozone depletion and photochemical smog. Results  Two soybean loops were established to demonstrate how an increased demand for soybean meal affects the palm oil and rapeseed oil production, respectively. The characterized results from LCA on soybean meal (with palm oil as marginal oil) were 721 gCO2 eq. for global warming potential, 0.3 mg CFC11 eq. for ozone depletion potential, 3.1 g SO2 eq. for acidification potential, −2 g NO3 eq. for eutrophication potential and 0.4 g ethene eq. for photochemical smog potential per kg soybean meal. The average area per kg soybean meal consumed was 3.6 m2year. Attributional results, calculated by economic and mass allocation, are also presented. Normalised results show that the most dominating impact categories were: global warming, eutrophication and acidification. The ‘hot spot’ in relation to global warming, was ‘soybean cultivation’, dominated by N2O emissions from degradation of crop residues (e.g., straw) and during biological nitrogen fixation. In relation to eutrophication and acidification, the transport of soybeans by truck is important, and sensitivity analyses showed that the acidification potential is very sensitive to the increased transport distance by truck. Discussion  The potential environmental impacts (except photochemical smog) were lower when using rapeseed oil as the marginal vegetable oil, because the avoided production of rapeseed contributes more negatively compared with the avoided production of palm oil. Identification of the marginal vegetable oil (palm oil or rapeseed oil) turned out to be important for the result, and this shows how crucial it is in consequential LCA to identify the right marginal product system (e.g., marginal vegetable oil). Conclusions  Consequential LCAs were successfully performed on soybean meal and LCA data on soybean meal are now available for consequential (or attributional) LCAs on livestock products. The study clearly shows that consequential LCAs are quite easy to handle, even though it has been necessary to include production of palm oil, rapeseed and spring barley, as these production systems are affected by the soybean oil co-product. Recommendations and Perspectives  We would appreciate it if the International Journal of Life Cycle Assessment had articles on the developments on, for example, marginal protein, marginal vegetable oil, marginal electricity (related to relevant markets), marginal heat, marginal cereals and, likewise, on metals and other basic commodities. This will not only facilitate the work with consequential LCAs, but will also increase the quality of LCAs.  相似文献   

12.
Life cycle assessment of printing and writing paper produced in Portugal   总被引:1,自引:0,他引:1  
Goal, Scope and Background The environmental sustainability is one of the current priorities of the Portuguese pulp and paper industry. Life Cycle Assessment (LCA) was the methodology chosen to evaluate the sustainability of the printing and writing paper production activity. This paper grade represents about 60% of the total production of paper in Portugal and its production is expected to increase in the near future. The main goal of this study was to assess the potential environmental impacts associated with the entire life cycle of the printing and writing paper produced in Portugal from Eucalyptus globulus pulp and consumed in Germany, in order to identify the processes with the largest environmental impacts. Another goal of this study was to evaluate the effect on the potential environmental impacts of changing the market where the Portuguese printing and writing paper is consumed: German market vs. Portuguese market. Methods The main stages considered in this study were: forestry, pulp production, paper production, paper distribution, and paper final disposal. Transports and production of chemicals, fuels and energy in the grid were also included in these stages. Whenever possible and feasible, average or typical data from industry were collected. The remaining data were obtained from the literature and specialised databases. A quantitative impact assessment was performed for five impact categories: global warming over 100 years, acidification, eutrophication, non-renewable resource depletion and photochemical oxidant formation. Results In the German market scenario, the paper production stage was a remarkable hot spot for air emissions (non-renewable CO2, NOx and SO2) and for non-renewable energy consumption, and, consequently, for the impact categories that consider these parameters: global warming, acidification and non-renewable resource depletion. These important environmental impacts are due to the energy requirements in the printing and writing paper production process, which are fulfilled by on-site fuel oil burning and consumption of electricity from the national grid, which is mostly based on the use of fossil fuels. The pulp production stage was identified as the largest contributor to water emissions (COD and AOX) and to eutrophication. Considering that energy consumed by the pulp production processes comes from renewable fuels, this stage was also the most contributing to renewable energy consumption. Discussion The paper distribution stage showed an important contribution to NOx emissions, which, however, did not result in a major contribution to acidification or eutrophication. The final disposal stage was the main contributor to the photochemical oxidant formation potential due to CH4 emissions from wastepaper landfilling. On the other hand, paper consumption in Portugal was environmentally more favourable than in Germany for the parameters/impact categories where the paper distribution stage has a significant contribution (non-renewable CO2, NOx, non-renewable energy consumption, acidification, eutrophication and non-renewable resource depletion) due to shorter distances needed to deliver paper to the consumers. For the remaining parameters/impact categories, the increase observed in the final disposal stage in the Portuguese market was preponderant, and resulted from the existence of significant differences in the final disposal alternatives in the analysed markets (recycling dominates in Germany, whereas landfilling dominates in Portugal). Conclusions The pulp and paper production stages were found to be of significance for almost all of the inventory parameters as well as for the impact assessment categories. The paper distribution and the final disposal stages were only of importance for some of the inventory parameters and some of the impact categories. The forestry stage played a minor role in the environmental impacts generated during the paper life cycle. The consumption of paper in Portugal led to a decrease in the environmental burdens of the paper distribution stage, but to an increase in the environmental burdens of the final disposal stage, when compared with the consumption of paper in Germany. Recommendations and Perspectives This study provides useful information that can assist the pulp and paper industry in the planning of future investments leading to an increase in its sustainability. The results of inventory analysis and impact assessment show the processes that play an important role in each impact category, which allow the industry to improve its environmental performance, making changes not only in the production process itself, but also in the treatment of flue gases and liquid effluents. Besides that concern regarding pollution prevention, other issues with relevance to the context of sustainability, such as the energy consumption, can also be dealt with.  相似文献   

13.

Purpose

System modelling and life cycle assessment (LCA) were used to assess the climate change, acidification and eutrophication impacts of milk production using spring calving pasture-based system. The objective of the study was to evaluate the effect of climate and soil resources on the environmental impact per unit milk produced at the farm gate from low-cost, grass-based rotational-grazing dairy production.

Methods

A dairy system model, Dairy_sim, designed to identify optimum grass-based spring calving production systems considering the interaction between climate and soil resources was tested using the Irish National Dairy Blueprint and then used to assess regional differences of system management with well, moderately, mixed moderately-poorly and poorly drained soil resources available. Life cycle assessment was used to quantify environmental impacts of climate and soil drainage status. The Dairy_sim output was used as activity data for the LCA model.

Results and discussion

Differences were found in the management tactics influenced by climate and drainage resource. The impact of poor drainage reduced stocking rate, increased housing time and had greater need for later cut silage and more reliance on silage. Climate change, acidification and eutrophication impacts were greater for optimum management on poorly drained soil. The climate change ranged from 1.06 kg CO2 eq./kg (well drained) to 1.18 kg CO2 eq./kg (poorly drained) of energy corrected milk (ECM). The acidification and eutrophication ranged from 3.87 to 6.85 g SO2 eq./kg ECM and 2.69 to 3.64 g PO4 eq./kg ECM, respectively. Around 50% of poorly drained soil resource can be easily accommodated in dairy systems with little increase in environmental impact, where poor drained portion is utilised for silage.

Conclusions

LCA combined with a system optimization model revealed how dairy farm management practises constrained by poor land resource increased the environmental impact per unit product.
  相似文献   

14.
A case study of a life-cycle assessment (LCA) is performed concerning the treatment of household solid wastes in a landfill. The stages considered in this LCA study are: goal and scope definition, inventory analysis and impact assessment. The data of the inventory include the consumption of raw materials and energy through the transport of wastes and the management of landfill, and the corresponding emissions to the environment. Abiotic resource depletion, global warming, acidification, eutrophication and human toxicological impacts have been considered as impact categories for the impact assessment phase of the LCA. A comparison of the environmental impact of the landfilling with and without energy recovery is carried out. Members of the Spanish Association for LCA Development (APRODACV)  相似文献   

15.
Unsustainable private consumption causes energy and environmental problems. This occurs directly (resource depletion and emissions through using cars for transport) or indirectly (purchase of consumer goods and services for which the production uses energy and emits damaging gases). A hybrid energy analysis proved that indoor energy consumption, mobility, and vacations are the main consumer categories from an energy point of view. Although energy is often used as a proxy for environmental load from private consumption, there are other proxies like methane (CH4), sulfur oxides (SOx), and land use. This article describes the results of the extension of the hybrid energy analysis with energy and ten environmental stressors (CH4, nitrous oxide [N2O], nitrogen, phosphate, SOx, nitrogen oxides [NOx], ammonia [NH3], nonmethane volatile organic compounds [NMVOCs], particulate matter [PM10], and land use), combined in five impact categories (global warming potential [GWP], acidification, eutrophication, summer smog, and land use). Household consumption was analyzed by dividing Dutch household expenditure into 368 consumer items in 11 categories. The results show that food impacts, in particular, are underestimated when only energy is taken into account. Food makes the highest contribution in three out of five impact categories when all ten stressors are taken into account. Within the food domain, meat and dairy consumer items have the highest environmental impact, about 45% of total food impact on average across all five impact categories. Looking in detail (368 consumer items), there are nine food items in the top ten most‐polluting items. Salad oil and cheese are the most polluting food items.  相似文献   

16.
Over the past decade, China has supplied over 90% of global rare earths, and in doing so bore significant environmental burdens from processing its complex ores. In this study, we used life cycle assessment to quantify environmental impacts for producing 1 kilogram (kg) of 15 rare earth elements from each major production pathway. The scope of assessment included the largest rare earth oxide (REO) production chain in Bayan Obo, as well as lesser known production chains for bastnäsite in Sichuan and in‐situ leaching of kaolin clays in the Seven Southern Provinces of China. This was followed by assessing impacts from the three major metal refining processes: molten salt electrolysis, calciothermic reduction, and lanthanothermic reduction. Among 11 impact categories assessed, results were highest for human toxicity that ranged between 13.1 and 50.4 kg 1,4‐dichlorobenzene‐eq (equivalent)/kg of rare earth metal?1, followed by eutrophication (0.04 to 1.26 kg phosphate‐eq/kg of rare earth metal?1), abiotic depletion potential of fossil fuels (592 to 1,857 megajoules per kg of rare earth metal?1), acidification (0.25 to 0.87 kg sulfur dioxide‐eq/kg of rare earth metal?1), and global warming (39.1 to 109.6 kg carbon dioxide‐eq/kg of rare earth metal?1) potentials. Regionally, impacts in Sichuan were lower across all key impact categories than in Bayan Obo: 32% lower for human toxicity, 67% lower for eutrophication, 58% lower for acidification, and 45% lower for global warming. A scenario analysis between the industry average and best available technologies revealed considerable potential to mitigate impacts across all production chains, particularly by improving waste treatment practices.  相似文献   

17.
Polymers based on olefins have wide commercial applicability. However, they are made from non-renewable resources and are characterised by difficulty in disposal where recycle and re-use is not feasible. Poly-beta-hydroxybutyric acid (PHB) provides one example of a polymer made from renewable resources. Before motivating its widespread use, the advantages of a renewable polymer must be weighed against the environmental aspects of its production. Previous studies relating the environmental impacts of petroleum-based and bio-plastics have centred on the impact categories of global warming and fossil fuel depletion. Cradle-to-grave studies report equivalent or reduced global warming impacts, in comparison to equivalent polyolefin processes. This stems from a perceived CO(2) neutral status of the renewable resource. Indeed, no previous work has reported the results of a life cycle assessment (LCA) giving the environmental impacts in all major categories. This study investigates a cradle-to-gate LCA of PHB production taking into account net CO(2) generation and all major impact categories. It compares the findings with similar studies of polypropylene (PP) and polyethylene (PE). It is found that, in all of the life cycle categories, PHB is superior to PP. Energy requirements are slightly lower than previously observed and significantly lower than those for polyolefin production. PE impacts are lower than PHB values in acidification and eutrophication.  相似文献   

18.
The tool for the reduction and assessment of chemical and other environmental impacts (TRACI) is a set of life-cycle impact assessment (LCIA) characterization methods that has been developed by a series of U.S. Environmental Protection Agency research projects. TRACI facilitates the characterization of stressors that may have potential effects, including ozone depletion, global warming, acidification, eutrophication, tropospheric ozone (smog) formation, eco-toxicity, human particulate effects, human carcinogenic effects, human non-carcinogenic effects, fossil fuel depletion, and land-use effects. This article describes the methodologies developed to address acidification, eutrophication, and smog. Each of these methods offers the ability to take account of differences in expected strength of impact as a function of pollution release location within North America. Specifically, the methods employ regionalized fate and transport modeling. The resulting factors differ regionally by up to more than an order of magnitude.  相似文献   

19.
This study was undertaken to evaluate the effect that switching from conventional to precision feeding systems during the growing-finishing phase would have on the potential environmental impact of Brazilian pig production. Standard life-cycle assessment procedures were used, with a cradle-to-farm gate boundary. The inputs and outputs of each interface of the life cycle (production of feed ingredients, processing in the feed industry, transportation and animal rearing) were organized in a model. Grain production was independently characterized in the Central-West and South regions of Brazil, whereas the pigs were raised in the South region. Three feeding programs were applied for growing-finishing pigs: conventional phase feeding by group (CON); precision daily feeding by group (PFG) (whole herd fed the same daily adjusted diet); and precision daily feeding by individual (PFI) (diets adjusted daily to match individual nutrient requirements). Raising pigs (1 t pig BW at farm gate) in South Brazil under the CON feeding program using grain cultivated in the same region led to emissions of 1840 kg of CO2-eq, 13.1 kg of PO4-eq and 32.2 kg of SO2-eq. Simulations using grain from the Central-West region showed a greater climate change impact. Compared with the previous scenario, a 17% increase in climate change impact was found when simulating with soybeans produced in Central-West Brazil, whereas a 28% increase was observed when simulating with corn and soybeans from Central-West Brazil. Compared with the CON feeding program, the PFG and PFI programs reduced the potential environmental impact. Applying the PFG program mitigated the potential climate change impact and eutrophication by up to 4%, and acidification impact by up to 3% compared with the CON program. Making a further adjustment by feeding pigs according to their individual nutrient requirements mitigated the potential climate change impact by up to 6% and the potential eutrophication and acidification impact by up to 5% compared with the CON program. The greatest environmental gains associated with the adoption of precision feeding were observed when the diet combined soybeans from Central-West Brazil with corn produced in Southern Brazil. The results clearly show that precision feeding is an effective approach for improving the environmental sustainability of Brazilian pig production.  相似文献   

20.
Willow Salix sp. is currently cultivated as a short rotation forestry crop in Ireland as a source of biomass to contribute to renewable energy goals. The aim of this study is to evaluate the energy requirements and environmental impacts associated with willow (Salix sp.) cultivation, harvest, and transport using life cycle assessment (LCA). In this study, only emissions from the production of the willow chip are included, end‐use emissions from combustion are not considered. In this LCA study, three impact categories are considered; acidification potential, eutrophication potential and global warming potential. In addition, the cumulative energy demand and energy ratio of the system are evaluated. The results identify three key processes in the production chain which contribute most to all impact categories considered; maintenance, harvest and transportation of the crop. Sensitivity analysis on the type of fertilizers used, harvesting technologies and transport distances highlights the effects of these management techniques on overall system performance. Replacement of synthetic fertilizer with biosolids results in a reduction in overall energy demand, but raises acidification potential, eutrophication potential and global warming potential. Rod harvesting compares unfavourably in comparison with direct chip harvesting in each of the impact categories considered due to the additional chipping step required. The results show that dedicated truck transport is preferable to tractor‐trailer transport in terms of energy demand and environmental impacts. Finally, willow chip production compares favourably with coal provision in terms of energy ratio and global warming potential, while achieving a higher energy ratio than peat provision but also a higher global warming potential.  相似文献   

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