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1.
When evaluating the environmental impacts of finfish production systems, both regional impacts (e.g., eutrophication) and global impacts (e.g., climate change) should be taken into account. The life cycle assessment (LCA) method is well suited for this purpose. Three fish farms that represent contrasting intensive production systems were investigated using LCA: rainbow trout (Oncorhynchus mykiss) in freshwater raceways in France, sea-bass (Dicentrarchus labrax) in sea cages in Greece, and turbot (Scophtalmus maximus) in an inland re-circulating system close to the seashore in France. Two main characteristics differentiated the three farm systems: feed use and energy use. Emission of nitrogen and phosphorus accounted for more than 90% of each farm's potential eutrophication impact. In the trout and sea-bass systems, feed production was the major contributor to potential climate change and acidification impacts and net primary production use (NPPU). In these systems, the main source of variation for environmental impacts was the feed conversion ratio. Results from this study indicate that the sea-bass cage system was less efficient than the trout raceway system, with a higher level of potential eutrophication (65% greater) and NPPU (15% greater). The turbot re-circulating system was a high energy-consumer compared to the trout raceway system (four times higher) and the sea-bass cage system (five times higher). Potential climate change and acidification impacts were largely influenced by energy consumption in the turbot re-circulating system. In the turbot re-circulating system 86% of energy use was due to on-site consumption, while in the sea-bass cage farming system 72% of energy use was due to feed production. These results are discussed in relation to regional contexts of production and focus attention on the sensitivity of each aquatic environment and the use of energy carriers.  相似文献   

2.
Global demand for bio-fuels continues unabated. Rising concerns over environmental pollution and global warming have encouraged the movement to alternate fuels, the world ethanol market is projected to reach 86 billion litres this year. Bioethanol is currently produced from land-based crops such as corn and sugar cane. A continued use of these crops drives the food versus fuel debate. An alternate feed-stock which is abundant and carbohydrate-rich is necessary. The production of such a crop should be sustainable, and, reduce competition with production of food, feed, and industrial crops, and not be dependent on agricultural inputs (pesticides, fertilizer, farmable land, water). Marine biomass could meet these challenges, being an abundant and carbon neutral renewable resource with potential to reduce green house gas (GHG) emissions and the man-made impact on climate change. Here we examine the current cultivation technologies for marine biomass and the environmental and economic aspects of using brown seaweeds for bio-ethanol production.  相似文献   

3.
叶绿素a的浓度能够表征海域富营养化状况,是反映海洋环境状态的一个重要指标。本研究以深圳海域为研究区,基于环境一号卫星遥感影像和实测叶绿素a浓度数据,将陆源入海排污口的核密度、距港口航道的距离和距海水增养殖区的距离作为环境变量,在Matlab平台中分别构建了基于环境一号卫星四个波段反射率为输入参数的误差逆向传播神经网络模型,及在此基础上引入了环境变量的误差逆向传播神经网络模型,以检验环境变量的引入能否提高叶绿素a浓度的反演精度,并对其输入参数进行敏感性分析。结果表明:(1)环境变量的引入能较大地提高误差逆向传播神经网络模型的反演精度,且引入环境变量的误差逆向传播神经网络模型的训练均方误差和验证均方误差分别为4.71 μg/L和3.50 μg/L,均优于原始误差逆向传播模型的10.98 μg/L和12.61 μg/L;(2)引入环境变量的误差逆向传播模型的框架如下:输入层为7个变量,分别为蓝光波段反射率、绿光波段反射率、红光波段反射率和近红外波段反射率、陆源入海排污口的核密度、距港口航道的距离和距海水增养殖区的距离;隐含层节点数为5个;输出层为叶绿素a的浓度;(3)叶绿素a的浓度对陆源入海排污口的核密度的变化最敏感,其次分别是近红外波段反射率、红光波段反射率、距港口航道距离、蓝光波段反射率、绿光波段反射率和距海水增养殖区的距离。  相似文献   

4.
当前海洋塑料和微塑料污染问题是全球研究热点,随着我国陆源垃圾减量化处置率和生活污水处理覆盖率的提高,重新核算我国海洋塑料垃圾和微塑料排放量尤为重要,基于文献已报道的关于海洋塑料垃圾和微塑料排放量估算的方法并结合相关统计数据对我国相应排放量进行了核算.结果表明:2016年我国向海洋中排放塑料垃圾124×104~331×104 t,略低于2010年的132×104~353×104 t;生活污水处理厂向环境中排放塑料微珠约109.95×1012粒(折合131.78 t),远低于2014年报道的209.7×1012粒(折合306.9 t).此外,2016年我国生活污水处理厂向环境中排放合成化学纤维类微塑料约1 296.95×1012个(折合648.48 t),轮胎与地面摩擦产生合成橡胶轮胎粉尘约78.85×104 t;合成化纤类微塑料和合成橡胶轮胎粉尘等已成为陆源微塑料的重要来源.通过与发达国家和地区在海洋垃圾和微塑料污染、陆源垃圾处置、海洋垃圾污染应对等方面进行比较,未来我国应通过完善"限塑令"和生活垃圾分类体系、尽早实施"塑料微珠"限令、明晰生活污水处理厂微塑料排放状况等手段从源头控制排放,此外需有效控制塑料垃圾和微塑料的输送途径,制定和完善相关法律法规和监测标准,提升我国应对海洋塑料垃圾和微塑料污染的能力和国际影响力.   相似文献   

5.
Livestock production systems will inevitably be affected as a result of changes in climate and climate variability, with impacts on peoples’ livelihoods. At the same time, livestock food chains are major contributors to greenhouse gas emissions. Agriculture and livestock in particular will need to play a greater role than they have hitherto in reducing emissions in the future. Adaptation and mitigation may require significant changes in production technology and farming systems, which could affect productivity. Given what is currently known about the likely impacts on livestock systems, however, the costs of mitigating and adapting to climate change in the aggregate may not represent an enormous constraint to the growth of the global livestock sector, in its bid to meet increasing demand for livestock products. Different livestock systems have different capacities to adapt or to take on board the policy and regulatory changes that may be required in the future. Vulnerability of households dependent on livestock, particularly in the drier areas of developing countries, is likely to increase substantially, with concomitant impacts on poverty and inequity. The capacity of these systems to adapt and to yield up their carbon sequestration potential deserves considerable further study. Comprehensive frameworks need to be developed to assess impacts and trade-offs, in order to identify and target adaptation and mitigation options that are appropriate for specific contexts, and that can contribute to environmental sustainability as well as to poverty alleviation and economic development.  相似文献   

6.
Interest in producing ethanol from biomass in an attempt to make transportation ecologically sustainable continues to grow. In recent years, a large number of assessments have been conducted to assess the environmental merit of biofuels. Two detailed reviews present contrasting results: one is generally unfavourable, whilst the other is more favourable towards fuel bio-ethanol. However, most work that has been done so far, to assess the conversion of specific feedstocks to biofuels, specifically bio-ethanol, has not gone beyond energy and carbon assessments. This study draws on 47 published assessments that compare bio-ethanol systems to conventional fuel on a life cycle basis, or using life cycle assessment (LCA). A majority of these assessments focused on net energy and greenhouse gases, and despite differing assumptions and system boundaries, the following general lessons emerge: (i) make ethanol from sugar crops, in tropical countries, but approach expansion of agricultural land usage with extreme caution; (ii) consider hydrolysing and fermenting lignocellulosic residues to ethanol; and (iii) the LCA results on grasses as feedstock are insufficient to draw conclusions. It appears that technology choices in process residue handling and in fuel combustion are key, whilst site-specific environmental management tools should best handle biodiversity issues. Seven of the reviewed studies evaluated a wider range of environmental impacts, including resource depletion, global warming, ozone depletion, acidification, eutrophication, human and ecological health, smog formation, etc., but came up with divergent conclusions, possibly due to different approaches in scoping. These LCAs typically report that bio-ethanol results in reductions in resource use and global warming; however, impacts on acidification, human toxicity and ecological toxicity, occurring mainly during the growing and processing of biomass, were more often unfavourable than favourable. It is in this area that further work is needed.  相似文献   

7.
华北高产粮区夏玉米生命周期环境影响评价   总被引:7,自引:3,他引:4  
以山东省桓台县夏玉米生产体系为例,应用生命周期评价方法,以单位产量为评价功能单元,把夏玉米生命周期分为原料开采与运输、农资生产与运输、作物种植3个生产阶段,对不同施氮水平下夏玉米生命周期的资源消耗与污染物排放进行了清单分析和影响评价.结果表明,随着施氮量的增加,夏玉米生命周期环境影响呈指数上升趋势,其中,主要影响类型为水资源耗竭,这与农作物需水量较大、水分生产率较低有关.在低氮量条件下,主要污染影响类型是全球变暖,随着施氮量的增加,富营养化上升为主要污染影响类型.提高作物种植阶段水肥利用效率是控制夏玉米生命周期环境影响的关键,它可减少夏玉米对水资源和氮肥的需求,从而直接减少农田氮素损失污染影响,也间接降低了上游生产环节的资源消耗与污染物排放影响,进而有助于降低夏玉米生命周期环境影响总潜力.  相似文献   

8.
电动与内燃机汽车的动力系统生命周期环境影响对比分析   总被引:3,自引:2,他引:3  
以国内某两款同一车型的电动与内燃机汽车的动力系统为研究对象,通过生命周期分析软件GaBi建立生命周期评价(LCA)模型,在清单数据分析的基础上,采用CML2001模型对两种动力系统分别进行了定量的生命周期环境影响评价.评价结果表明,电动汽车动力系统的全生命周期综合环境影响比内燃机汽车动力系统高60.15%,并分别通过回收阶段分析、电能结构分析和敏感性分析对这一结果进行了解释:回收阶段中酸化、富营养化和光化学臭氧合成3种环境影响类型的直接排放大于回收得到的环境效益;电动汽车动力系统的环境影响随着火力发电比例的下降而减小,增大水能、风力和核能发电在电力系统中所占比例能有效降低电动汽车对环境的影响;动力系统重量对电动汽车动力系统的环境排放影响最为敏感,电池充电效率次之,制造阶段能耗的敏感度最小.将动力系统使用阶段的环境影响分配到整车,则电动汽车的生命周期环境影响比内燃机汽车低0.14%,且主要环境影响类型是全球变暖、酸化和富营养化.  相似文献   

9.
农村污水排放所导致的环境问题日益突出,各地均大力推动污水处理模式的建立与优化.但农村污水处理模式综合效能评价体系匮乏,且多以处理工艺为主,少量考虑了管网收集系统的环境经济影响.另外,河口岛屿因其独特的自然区位,生态更加脆弱敏感,研究其污水处理问题更具有价值与意义.因此,本研究选取河口岛屿为研究对象,以崇明为例,运用生命周期评价和经济性分析理论,对比分析了分散与原位两种生活污水处理模式,包含收集和处理系统两个子系统,以及建设和运行两个阶段的环境影响与经济性.结果表明:原位和分散模式环境影响总值分别为1.75×10-11和0.66,分散模式更具环境优势;户均成本分别为1.80万元和1.66万元,相比原位模式而言,在相同去除效果条件下,分散模式处理更有利于节约单位投资费用;处理系统为污水处理模式主要环境影响贡献子系统,其运行阶段为主要贡献阶段,且收集系统更有环境无害化和经济优势;海洋生态毒性潜值和人体毒性潜值为主要环境影响类型.  相似文献   

10.
陈熙  高翊尧  凌玮  柳青  沈茜  安立会  王琛 《环境科学研究》2019,32(12):1959-1965
海洋垃圾已引起国际社会的广泛关注,是当前环境领域热点问题之一.为揭示我国渤海近岸海域海洋垃圾的赋存特征及其分布规律,于2018年丰水期(8月)在辽东湾河口区海域布设6个长度为5~10 km的调查断面,利用拖网同时采集海面漂浮垃圾与海底垃圾,初步调查辽东湾近岸海域海洋垃圾分布和组成特征,并对海洋垃圾来源进行了分析.结果表明:①辽东湾海面漂浮垃圾数量密度为67个/km2,质量密度为741 g/km2;海底垃圾数量密度为19个/km2,质量密度为2 544 g/km2.②在所收集的各类海洋垃圾中,塑料类垃圾数量占比约为50.9%,其中海底塑料类垃圾数量占比(62.1%)明显高于海面漂浮塑料垃圾数量占比(37.5%).③由塑料垃圾形态特征和表面带有的标识判断,辽东湾近岸海域塑料垃圾主要是来源于生活塑料垃圾(84.9%)和渔业垃圾(15.1%).在此基础上,建议加强源头管理以减少塑料垃圾进入海洋,主要包括完善当前海洋垃圾分类方法、加强渔业塑料垃圾回收、提升公民保护海洋环境意识和制定国家海洋塑料垃圾行动计划等.   相似文献   

11.
海洋沉积物的质量评价与管理   总被引:2,自引:1,他引:1  
海洋管理者迫切需要建立评估海洋中沾污沉积物引发海洋资源负效应程度的方法。本文就此考察了评价海洋沉积物受人类活动影响的方法,以及相关的海洋生物和人类健康的风险,通过总结过去的评价工作,确定辨别天然沉积物、人类活动干扰(沾污的)的沉积物和引发负效应(污染的)的沉积物状况的经验程序。在一定程度上指出了符合科学有效性和管理实用性标准的方法,为管理者在海洋环境评价和管理中使用章程、法规、标准和规范的提供了指导,而且对审批疏浚和废物排放、实施环境法规和解释监测计划结果也会起到一定作用。  相似文献   

12.
This study evaluates the environmental impact of the cement production and its variations between different cement plants, using Life Cycle Impact Assessment. For that purpose, details of the cement production processes are investigated in order to show the respective part of raw materials preparation and clinker production using environmental impacts calculated with CML01 indicators. For the kiln emission data, a European pollutant emission register for French intensive industries is used to quantify the variability of indicators between cement plants. For the CML01 indicators that are controlled by kiln emissions, some of them (i.e. global warming, photochemical oxidation) show variations between cement plants between 20 and 30%, as for other (i.e. acidification, eutrophication, terrestrial ecotoxicity) variations are greater than 40% due to the lack of accurate measurements on both pollutant content and annual flow. Finally, a normalisation, using Western Europe yearly emissions is performed and permits to highlight among all the CML01 indicators which ones are the main impacts for the cement production. Abiotic depletion, global warming, acidification and marine ecotoxicity are the four identified impacts.  相似文献   

13.
目前微塑料污染已经造成全球性的环境问题,其中海洋环境的微塑料污染问题尤为突出,入海河流是陆地与海洋相互作用的重要通道,海洋的陆源物质大多经河流迁移入海,因此入海河流的水质状况及污染物输送量成为陆地对海洋影响的中心问题.该研究通过系统调研,综述了近年来全球范围内有关入海河流的微塑料入海通量与丰度的内容与方法研究;据最近研究估计,陆源的微塑料通量占海洋环境塑料碎片总量的64%~90%,全球河流每年向海洋运输的塑料碎片(微塑料和大塑料)总量为0.41×106~4×106 t,但全球模型是否适用于特定流域仍需校正和检验;从方法学角度而言,对微塑料丰度数据的采集是研究河流微塑料入海通量的基本前提,并且目前缺乏统一的监测和分析等研究方法,使得不同河流之间通量难以直观对比,加之实测数据不足,导致入海河流中微塑料的陆源分析及定量研究仍处于初步阶段;未来的研究中应注重将微塑料运输量与河流流量高度耦合的数据优化方式,以基于水动力模型阐明微塑料在河流入海过程中的迁移及转化机制.此外,应在全球范围内开展广泛密切的国际合作,建立统一的研究体系,不断完善全球微塑料研究的基础数据库信息,推动国际社会共同应对微塑料污染.   相似文献   

14.
The aim of this paper is to examine the environmental consequences of beef meat production in the EU, using a life cycle approach. Four beef production systems were studied – three from intensively reared dairy calves and one from suckler herds. According to the results of the analysis, the contributions from the production of 1 kg beef meat (slaughter weight) to global warming, acidification, eutrophication, land use and non-renewable energy use were lower for beef from dairy calves than from suckler herds (16.0–19.9 versus 27.3 kg CO2e, 101–173 versus 210 g SO2e, 622–1140 versus 1651 g NO3e, 16.5–22.7 versus 42.9 m2year, and 41.3–48.2 versus 59.2 MJ, respectively). The breakdown analysis helped identify the key areas in the “cradle to farm gate” beef production system where sustainable management strategies are needed to improve environmental performance. The study also included a sensitivity analysis to preliminarily estimate GHG emissions from beef production systems if land opportunity cost and land use change related to grazing and feed crop production for beef were taken into account. If so, the contribution from the production of 1 kg beef to global warming would increase by a factor of 3.1–3.9, based on a depreciation period of 20 years. This highlights the importance of taking into account the impacts of land use in assessing the environmental impacts of livestock production.  相似文献   

15.
The most fundamental aspect in the ISO 14001 standard Environmental management systems—Specification with guidance for use is to find out ways by which an organisation influences environment to a significant degree. This paper examines environmental data from companies manufacturing products mainly from metals and/or polymers. The data were collected in a uniform way by use of special guidelines. Weighting or valuation methods often used in life cycle assessments were used to quantitatively compare and rank environmental aspects. The study results suggest that, in general, the largest environmental impact in the investigated manufacturing sub-sector can be associated with product use and/or disposal phases. This in turn shows a need for more attention on environmental work on the design for environment than what the ISO 14001 standard requires. It is further suggested that weighting or valuation methods can aid in determining the significance of environmental impacts and aspects in the context of ISO 14001.  相似文献   

16.
《Journal of Cleaner Production》2005,13(13-14):1235-1245
There are decision situations where environmental impacts need to be compared with other costs or benefits that by their nature are expressed in terms of money. Supporting these decisions may require the expression of environmental impacts in monetary units. Using the example of health impacts from road noise we apply five different monetization approaches and quantify the monetary values of one year of sleep disturbance (CHF 2500–16 000) and interference with communication (1500–10 000). In Life Cycle Assessment many health endpoints need to be evaluated at the same time. Therefore, we illustrate here the transferability problem between health impacts measured in disability adjusted life years (DALYs) and monetized health impacts, using the example of health impacts due to 1000 truck kilometres. It is concluded that available monetization methods need careful adaptation for their use to monetize environmental health impacts, that the DALY accounting system may support the systematic monetization and the selection of relevant health endpoints, and that it may well be justified for LCA purposes to perform some novel primary willingness to pay studies.  相似文献   

17.
设施番茄生产系统的环境影响生命周期评价   总被引:5,自引:0,他引:5  
应用生命周期评价方法,以陕西省西安市郊区为例,对设施番茄生产系统进行了环境影响评价.结果表明,日光温室和塑料大棚生产1000kg番茄消耗的能源和水资源分别是1740.58 MJ、50.767 m3和1502.346 MJ、53.734 m3;全球变暖潜值(以CO2当量计)、环境酸化潜值(以SO2当量计)、富营养化潜值(以PO3-4当量计)、光化学烟雾潜值(以C2H2当量计)、土壤毒性(以1,4-DCB当量计)、水体毒性(以1,4-DCB当量计)和人类毒性潜值(以1,4-DCB计)分别为271.943 kg、2.151 kg、0.247 kg、0.157 kg、24.217 kg、19.545 kg、0.124 kg和239.163 kg、1.88 kg、0.305 kg、0.109 kg、31.686 kg、19.7 kg、0.304 kg.设施构筑物自身建设和维护带来的主要潜在环境影响是能源耗竭、全球变暖和环境酸化;番茄种植环节引起的主要潜在环境影响是水资源耗竭、富营养化、全球变暖、土壤毒性和水体毒性;农资生产环节的主要潜在环境影响是能源耗竭.设施番茄生产系统中对环境影响大的建材和农资是钢材、聚乙烯材料、氮肥、农药和含过量重金属的有机肥.设施番茄生产系统对环境的影响不容忽视,应展开以降低其环境影响为目标的设施结构与建材、温室内气候条件调控、合理施肥和施药的研究,并对采取的技术方法进行生命周期评价,以确保设施蔬菜的可持续发展.研究结果可为促进设施蔬菜生产系统的可持续发展提供科学依据.  相似文献   

18.
Climate change is raising significant issues for European invasive species policy. As natural and anthropogenic systems experience changing climatic conditions, opportunities for the distribution and establishment of invasive exotic plant species are projected to increase. Such environmental changes will provide significant challenges for the strategic planning and management of natural, agricultural and urban spaces. In this study, the perceptions of the impacts of invasive exotic plant species are examined and compared to perceptions of other environmental issues on the islands of Mallorca, Sardinia and Crete. A survey of key stakeholders was undertaken on the Mediterranean islands with the use of questionnaires and in-depth interviews. While there is a widespread tolerance of environmental change associated with the establishment of invasive species on the islands, local stakeholders raise concerns about specific impacts and the policies in place to respond to future risk. To build resilience within natural and anthropogenic systems to the changing climatic circumstances, a need exists for integrative environmental policy that supports local capacity to manage invasive species within Mediterranean landscapes.  相似文献   

19.
采用生命周期分析方法,以1 000 L甘薯乙醇为单位功能单元,将甘薯乙醇生产体系分成作物种植、原料运输和乙醇转换等3个单元,对其生命周期能耗与环境排放进行清单分析和影响评价,比较习惯施肥与测土配方施肥下甘薯乙醇生命周期9类环境影响潜力的差异。结果表明:两种施肥模式下甘薯乙醇生产体系的生命周期能源效率分别为1.41和1.43。习惯施肥模式下甘薯乙醇生命周期主要环境影响类型包括人体毒性、富营养化、酸化、淡水生态毒性、能耗和全球变暖,其环境影响潜力分别相当于2000年世界人均影响潜力的40%、40%、31%、29%、25%和20%。测土配方施肥降低了化学氮肥和磷肥使用量,提高了肥料利用效率和甘薯单产,使富营养化、淡水生态毒性、酸化和全球变暖潜力分别降低了31%、15%、9%和7%。可见,测土配方施肥模式可改善甘薯乙醇生命周期的能源效率并显著缓解其负面环境影响。  相似文献   

20.
It is not known to what extent the outcome of studies assessing the environmental impacts of agricultural systems depends on the characteristics of the evaluation method used. The study reported here investigated five well-documented evaluation methods (DIALECTE, Ecological Footprint, Environmental Management for Agriculture, FarmSmart, Life Cycle Assessment) by applying them to a case study of three pig farm scenarios. These methods differ with respect to their global objective (evaluation of impact versus evaluation of adherence to good practice), the number and type of environmental issues they consider, the way they define the system to be analysed, the mode of expression of results (for the farm as a whole, per unit area or per unit product) and the type of indicators used (pressure, state or impact indicators). The pig farm scenarios compared were conventional good agricultural practice (GAP), a quality label scenario called red label (RL) and organic agriculture (OA). We used the methods to rank the three scenarios according to their environmental impacts. The relative ranking of the three scenarios varied considerably depending on characteristics of the evaluation method used and on the mode of expression of results. We recommend the use of evaluation methods that express results both per unit area and per unit product. Environmental evaluation methods should be used with great caution, users should carefully consider which method is most appropriate given their particular needs, taking into consideration the method's characteristics.  相似文献   

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