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301.
Dewulf J van Langenhove H 《Environmental science and pollution research international》2002,9(4):267-273
Life cycle analysis is one of the tools in the assessment of the sustainability of technological options. It takes into account all effects on the ecosystem and the population which may endanger the possibilities of current and future generations. However, the main bottleneck in current LCA methodologies is the balancing of different effects, being all quantified on different scales. In this work, a methodology is proposed, which allows one to quantify different effects of the production, consumption and disposal of goods, and services on a single scale. The basis of the methodology is the second law of thermodynamics. All production, consumption and disposal processes affecting the ecosystem and the population, are quantified in terms of loss of exergy. The exergy content of a material is the maximum amount of energy which can be transformed into work at given environmental conditions. Next to the elaboration of the methodology, the new approach is illustrated by examples of the production of synthetic organic polymers, inorganic building insulation materials and different waste gas treatment options. 相似文献
302.
Alejandra Valero Robyn Hudson Edgar Ávila Luna Constantino Macías Garcia 《Behavioral ecology and sociobiology》2005,59(2):262-269
When approached by males, females of the Amarillo fish (Girardinichthys multiradiatus) perform a behaviour called vibration or they are aggressively challenged. We quantified vibration and assessed whether it compromises the rate of feeding attempts in dyads kept in outdoor enclosures. Male approaches resulted in female vibration and in a reduced feeding rate. Vibration was not evoked by female–female aggression, which was frequent and always ended in the subordinate fleeing from the dominant female. Using a closed respirometer we found that vibration is costly; oxygen consumption of females was greater in the presence of a male (which evoked vibration) than in the presence of a non-familiar female (when no vibration occurred). By recording interactions of females confined in aquaria in the presence and in the absence of males, we confirmed that escaping is the only available response to deal with female aggression. Females kept without males participated in frequent aggressive (even lethal) interactions that did not abate while the subordinate female was in sight of the dominant, and which caused premature births and injuries. Yet in the alternative treatment aggression ceased when a male approached, prompting vibration in both females. Thus, in the Amarillo, in as much as it evokes energetically costly female vibrations, male courtship is an expression of sexual conflict. However, in the absence of males, frequent female aggression potentially annuls the benefits of not vibrating. We propose that a complete appraisal of the consequences of sexual conflict must include an assessment of the costs imposed by intra-sexual interactions. 相似文献
303.
On thresholds and environmental curve tensiometers 总被引:1,自引:0,他引:1
This paper considers distinctions between lognormal and mixture models. Emphasis is placed on two component mixtures where the lower valued subpopulation has a large mixing parameter. The density of this sort of mixture can be easily mistaken for a lognormal density. In order to compare such a mixture to a lognormal it is demonstrated that Galton's two parameter logmodel and Pearson's five parameternormal mixture are special, or limiting, cases of the same general mixture model. Consideration is given to the lognormal threshold parameter in order to devise a tool that can help distinguish mixtures from lognormals. Based on the threshold parameter, piloted procedures can help measure whether or not a curve is friable, in the sense that a brittle curve is better represented as a mixture than as a skewed lognormal. It is also shown that generalizations of Galton's product risk model can be represented interms of the threshold parameter Based on a tool called a curve tensiometer was designed to be applied as a graphical friability check in the ecological context of Fisher's classic Iris data and in the environmental context of a Santa Monica Bay fish consumption study. 相似文献
304.
低药耗费通试剂氧化乙二醇废水的实验研究 总被引:5,自引:0,他引:5
对排放量小,间歇排放的乙二醇废水进行费通试剂催化氧化处理的条件研究。结果表明,在合适的条件下,采用费通试剂催化氧化--加碱凝聚分离--处理水循环回流的工艺。CODCr去除率达96%,处理水可稳定达标排放。此工艺具有降低药耗,提高CODcr去除率的双重效果。 相似文献
305.
306.
高浓度甲基橙湿式过氧化氢氧化及机理初探 总被引:4,自引:0,他引:4
采用湿式过氧化氢氧化法 (WPO)处理高浓度偶氮染料甲基橙溶液 ,考察了多种因素对去除效果的影响 ,结果表明 ,对于 4 0 0mg L的甲基橙溶液 ,其最佳处理条件为 :温度 16 0℃ ,H2 O2 浓度 33mg L ,Fe2 + 浓度为 91 2mg L ,处理后脱色率在 95 %以上。对比废水处理前后紫外光谱与红外光谱图的变化 ,说明染料分子结构中的偶氮键发生断裂 ,破坏了分子结构的偶氮 -苯环共轭发色体系 ,从而达到了脱色的目的 相似文献
307.
研究了US/Fenton协同作用对水中苯酚的降解效果,探讨了Fenton试剂浓度、H2O2,Fe^2+配比、溶液pH值等对苯酚降解效果的影响。结果表明:Fenton试剂投加量的增加对降解反应先促进后抑制;当H2O2/Fe^2+配比为40:1,H2O2投加量为40mmol/L,溶液pH值3.0~7.0时,US/Fenton对苯酚的降解速率最快.反应30min后的降解效率远大于单独US、Fenton试剂氧化处理下的降解效率总和.其表现一级动力学速率常数增强因子可达到2.45,表明US/Fenton联用存在明显的协同效应。 相似文献
308.
研究了Fenton试剂氧化+厌氧生物组合工艺处理纸浆废水的可行性,确定了Fenton试剂氧化处理的影响因素并对氧化出水进行了有关厌氧生物处理,结果证明采用化学氧化与生物处理相结合的处理方案是可行的。 相似文献
309.
中国能源消费与温室气体排放预测分析 总被引:4,自引:0,他引:4
构造了中国18个部门的能源—经济—环境投入产出模型,分析了能源消耗系数的变动规律,对2020年我国能源消费量与温室气体排放量进行了预测。结果表明:我国2020年的能源消费总量为29.5亿t(标准煤),等于1990年的299%,1995年的229%;煤炭消费最为26亿t,石油消费量为4.1亿t,天然气消费量为1420亿m~3,水电6400亿kW·h;能源消费弹性系数为0.43左右;CO_2排放量为17.50亿t(碳当量)。 相似文献
310.
Fe2+-H2O2催化氧化加混凝处理苯酚磺酸废水 总被引:2,自引:0,他引:2
采用H2O2-Fe^2 催化氧化-混凝联合工艺对苯酚磺酸(PSA)废水进行了试验研究,对H2O2和Fe^2 的投加量、pH值、温度(T)、时间(t)等工艺参数进行了优选。结果表明,在H2O2/COD0(g/g)=1.5,H2O2/Fe^2 (moL/moL)=10:1、pH=3.0-4.0、T=30℃、t=30min的条件下,COD为1198mg/L的PSA废水经该工艺处理,COD去除率达94%。试运行结果表明,其出水水质达到国家排放标准(GB8978-1996)。 相似文献