热水器生命周期环境影响评价模型及其应用研究

在现有热水器环境影响评价方法比较的基础上,用生命周期环境影响评价方法建立热水器的环境影响评价模型,计算分析热水器产品资源消耗、臭氧耗竭、能源强度和全球变暖四个指标,分析评价结果表明,四个指标在生命周期贡献值大小依次是臭氧耗竭、全球变暖、能源强度和资源消耗.热水器环境影响较大的零部件有压缩机、制冷剂、电机和铜管等.并对比分析了四种环境影响评价方法,得出生命周期环境影响评价模型是较为全面的评价模型.     

Theoretical Calculation and Economic Assessment of the Integrated Solar Combined Cycle Power Plants

The ISCC technology representing an integrated solar combined cycle and the economic assessment of ISCC are investigated. Comparisons conducted by theoretical calculation method among two cases, that is, an integrated solar combined cycle system (ISCCS) and a combined cycle gas turbine system (CCGTS) show that ISCCS provides the best solution with the highest efficiency of heat to electricity among them. The results reflected by theoretical calculation also reveal that ISCCS is beneficial to energy saving and emission reduction. Due to the great advantages of ISCC, comprehensive analysis on the basic conditions for building ISCC power plants is analyzed in detail.     

Environmental impact of two electrical products with reference to the energy-using products directive

High energy consumption is one of the major factors that contributes to global warming. Connected to this, a directive has been approved by the European Union for establishing a legal framework to govern eco-design of energy-using products. This technical note reveals life cycle analysis of two electrical products, which rely on the same rechargeable battery system (i.e. the same energy source) for operations, with respect to the requirements of the aforementioned directive. Results concur with the argument that energy consumption of this sort of product plays a dominant role in terms of a variety of environmental impacts (like emission to air). Based on the results of this study, eco-design alternatives can be derived accordingly so that energy consumption and the existing solution can be benchmarked, as required by the directive.     

Ecological-biogeochemical role of macrophytes in aquatic ecosystems of urbanized territories (an example of small water bodies of St. Petersburg)

The accumulation of heavy metals (Fe, Mn, Zn, Cu, Cr, Ni, Pb, Cd) and biogenic elements (P, S, K, Ca, Na) in leaves has been studied in macrophytes of different ecological groups growing in small water bodies of St. Petersburg. The ecogeological and biogeochemical role of macrophytes in the water-aquatic plants-bottom sediments system and their contribution to the stability of aquatic ecosystem functioning under conditions of a megalopolis are considered. Prospects for using macrophytes for bioindication and phytoremediation of polluted aquatic ecosystems are discussed.     

生命周期评价在玉米种植及深加工产品中的应用

对LCA在玉米种植环境影响研究中的目标与范围定义、清单分析、环境影响指标与计算方法、结果解释等方面的研究进行了梳理分析，其中大部分文献均对碳足迹进行了计算，CML（Institute of Environmental Sciences of the University of Leiden）、ReCiPe（许多LCA领域研究人员共同开发）和IPCC（Intergovernmental Panel on Climate Change）方法是应用最多的3种方法，经分析计算得到国外玉米种植单位产量碳足迹均值为0.50kg CO₂-eq/kg，我国的均值为0.58kg CO₂-eq/kg.同时本文也对LCA在玉米深加工产品中的研究进展进行了分析整理，对今后LCA应用于玉米种植及深加工产品中的发展方向进行了展望.     

Understanding and communicating sustainability: global versus regional perspectives

While there is no single definition of sustainability, most would agree that it implies that a system is to be maintained at a certain level, held within certain limits. Sustainability denies run-away growth, but it also precludes any substantial set backs or cuts. This sustainability path is hard to reconcile with the renewal cycle that can be observed in most living systems developing according to their natural intrinsic mechanisms. Besides, since different human dominated systems are in significantly different states and stages of development, sustaining those states assumes maintaining social disparities in perpetuity. This creates a challenge in communicating the ideas of sustainability in different regions. Systems are parts of hierarchies where systems of higher levels are made of subsystems from lower levels. Renewal in components is an important factor of adaptation and evolution. But then sustainability of a system borrows from sustainability of a supra-system and rests upon lack of sustainability in subsystems. Therefore by sustaining certain systems beyond their renewal cycle, we decrease the sustainability of larger, higher level systems. The only way to resolve this contradiction is to agree that the biosphere as a whole with humans as one of its components is the only system which sustainability we are to seek. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

Behavior of Two Phenyl Urea Herbicides in Clayey Soils and Effect of Alternating Dry-Wet Conditions on their Availability

Adsorption and mobility of linuron (3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea) and diuron (3-(3,4-dichlorophenyl)-1, 1-dimethylurea) were studied in clayey soils from the Gharb area (Morocco). Soils A and B were planted with sun flower (Helianthus annuus) while soil C was planted with sugar cane (Saccharum offcinarum). Adsorption was studied for linuron in soils A and B, while mobility was studied only in soil B. Adsorption data were found to fit the Freundlich equation with correlation coefficients r² > 0.9. Freundlich coefficients (K_f, n_f) were in agreement with L and S isotherm types for soils A and B, respectively. Values of K_oc (195 and 102) indicate moderate adsorption. Desorption isotherms for linuron showed hysteresis for both soils. The pesticide would be more bound to soil A (H = 8.44) than to soil B (H = 4.01). The effect of alternating wet and dry conditions was tested for soils A and B. Results showed that retention would increase in soil subject to an additional wet and dry cycle. In the case of diuron isotherm was of type L in soil C. Desorption was noticeable at high concentrations and tended to decrease when concentrations diminished. Mobility of linuron was tested in polyvinyle chloride (PVC) columns, which received different treatments before their percolation. The pesticide was more mobile in a previously saturated column. In columns subject to a drying step after saturation with water, linuron mobility was greatly reduced.     

麻疯树种子油生命周期的经济、环境与能量效率

要成为化石能源的有效替代品，生物燃料必须能提供净能量收益，能产生环境效益，具有经济效率，且在大量生产的情况下不引起粮食危机。麻疯树作为第二代生物柴油的重要原料作物，在国内得到大力推广，但实际效率尚不清楚。基于将麻疯树种子油与化石柴油直接混合使用的技术选择，利用生命周期评估法分析了麻疯树种子油生命周期的经济、环境和能量效率。结果表明：（1）在当前产量和生产技术水平下，生产和使用麻疯树种子油的财务净现值为负，要促进麻疯树种子油的生产，需要每年为种子生产者提供8817 元/hm2以上的补贴，为榨油厂商提供268 元/L的补贴；（2）生产和使用每升麻疯树种子油可减少约13 kgCO2当量的温室气体排放，固碳价值为补贴生产提供了部分经济依据，但是仅考虑种子油和固碳的价值时，生产和使用麻疯树种子油尚不具有经济可行性；（3）当仅考虑种子油的能量产出时，只有当种子产量达到795 kg/hm2以上才具有能量效率；当把树枝和果壳等所包含的生物质能计算在内时，在较低种子产量的情况下，也具有显著的能量效率。敏感性分析表明，随着麻疯树种子产量的增加，财务净现值趋于下降，但是种子油的成本下降，减排温室气体的贡献和能量效率都增加。最后，基于麻疯树种子油的生命周期分析，提出了提高经济、环境和能量效率的途径。〖     

水力发电技术的生命周期评价

以广东省内某一小型水电站为研究对象,对其进行了较系统的生命周期评价.通过目标和范围的确定,对水电站的各子过程进行了生命周期清单分析及环境影响潜值计算.分析表明,该水电站的总能耗为2.02g/(kW·h),其中煤占主要部分,占93.92％；该水电站排放的污染物中,CO2占绝大部分(96.70％),其次是粉尘(2.75％)；水电站的建设耗材生产子过程的能耗以及污染物排放量最大,该过程的能耗占总能耗的97.00％,污染物排放量占总排放量的94.41％；与常规燃煤电厂相比,每发电10000kW·h,该水电站可节约标煤3.98t,减少排放CO29.9648t、SOx79.927kg、NOx 49.92kg、粉尘499kg,水力发电具有非常显著的节能和环保效应；该水电站每发电lkW·h的总环境影响潜值为4.31×10-6人当量,其中粉尘是最主要的环境影响因素,这是由于水泥、钢材等建设耗材在制造生产过程中产生了大量的粉尘.     

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland

A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeled as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO₂-eq. generated in the incineration process, and 54 kg CO₂-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO₂-eq. Savings from energy recovery are in the range of 67 to 752 kg CO₂-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO₂-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles.