Waste treatment in product specific life cycle inventories

The final disposal of waste in sanitary landfills generates environmental impacts in the form of gaseous emissions and effluents in the seepage water. In product specific Life Cycle Assessments, these environmental impacts resulting from the disposal of the product under study frequently have a strong influence on the overall results. The Sanitary Landfill (SL), like the Municipal Solid Waste Incineration (MSWI), is a complex system with a large variety of different types of waste with varying input composition. A direct determination of the environmental impacts resulting from the landfilling of a single input component, e.g. by measurements, is not possible. The model approach described in this paper shows an operationalized concept for the allocation of the environmental effects caused by the landfill process to special input components. The calculation of the landfill emissions in the model is based on the emission spectrum (landfill gas and seepage water) of an average-sized landfill in Germany and the elementary composition of the single waste fraction under consideration. The resulting reactor landfill module comprises an average split for diffuse and captured landfill emissions, the use of captured landfill gases in a gas engine and a cleaning of captured seepage water in a waste water treatment plant. A short case study demonstrates the calculation of the effects of landfilling of a defined waste fraction (bottle fraction in post-consumer plastic waste).     

Consumption and the Rebound Effect: An Industrial Ecology Perspective

Measures taken to protect the environment often have other, unintended effects on society. One concern is that changed behavior may offset part of the environmental gain, something that has variously been labeled "take-back" or "rebound." In energy economics, the rebound effect encompasses both the behavioral and systems responses to cost reductions of energy services as a result of energy efficiency measures. From an industrial ecology perspective, we are concerned about more than just energy use. Any given efficiency measure has several types of environmental impacts. Changes in the various impact indicators are not necessarily in the same direction. Both co-benefits and negative side effects of measures directed to solve one type of problem have been identified. Environment is often a free input, so that a price-based rebound effect is not expected, but other indirect effects not connected to the price, such as spillover of environmental behavior, also occur. If the costs and impact of products that are already environmentally friendly are reduced, the "rebound" can be in the opposite, desired direction. Furthermore, I identify technical spillover effects. Hence a number of related effects, often producing positive results, are not as well understood. Household environmental impact assessments and eco-efficiency assessments take into account the rebound effect, but they do not necessarily take into account these other effects. The analysis hence indicates that the current focus on the rebound effect is too narrow and needs to be extended to cover co-benefits, negative side effects, and spillover effects.     

Expected Environmental Impacts of Pervasive Computing

Pervasive Computing will bring about both additional loads on and benefits to the environment. The prevailing assessment of positive and negative effects will depend on how effectively energy and waste policy governs the development of ICT infrastructures and applications in the coming years. Although Pervasive Computing is not expected to change the impact of the technosphere on the environment radically, it may cause additional material and energy consumption due to the production and use of ICT as well as severe pollution risks that may come about as a result of the disposal of electronic waste. These first-order environmental impacts are to be set off against the second-order effects, such as higher eco-efficiency due to the possibility to optimize material and energy intensive processes or to replace them by pure signal processing (dematerialization). The potential environmental benefits from such second-order effects are considerable and can outweigh the first-order effects. But changes in demand for more efficient services (third-order effects) can counterbalance these savings. The experience gained thus far with ICT impacts has shown that such a rebound effect occurs in most cases of technological innovations.     

药用植物资源利用的一种分析模型

在系统分析药用植物资源利用的各方面因素基础上,以资源利用模式为研究切入点,提出了一个基于资源利用模式和模式形成路径的分析模型（Pattem—Path Model）,用于整体分析某一药用体系中植物资源的开发利用水平和发展过程。应用该分析模型对2005版中国药典使用的药用植物资源（549种高等植物）进行了分析,结果表明：中国药典中应用的药用植物,其资源利用发展较成熟（供应持续性良好的植物资源占79％,暂不能持续供应的占21％）;但是资源利用的发展过程不尽合理（部分植物资源的栽培开展滞后于野生资源的枯竭,占40％）。该结论与已有定性评价观点相一致,并量化地体现出资源利用的发展水平和发展过程,能够推广应用到其他药用体系的资源利用分析,为药用植物资源的利用管理提供决策依据。     

The carbon budget of the Spanish forests

A model for the calculation of anthropogenic CO₂ emissions from perturbed forests (extraordinary emissions) is described. Timber production as well as wildfire statistics are used, and relevant physicochemical parameters are derived from the literature, to calculate the annual amounts of perturbed biomass and extraordinary emissions to the atmosphere from the Spanish forests — including soils — in the years 1960–1990; these emissions increased from 5.3 10⁶ t (metric tons) of carbon in 1970 to 10.6 10⁶ t C in 1990. A sensitivity analysis of the results has been performed to identify the most critical parameters. Contributions of observed timber growth and natural vegetal detritus and soil organic matter to the net forest carbon flux have been estimated to calculate the carbon budget in the Spanish forests between 1966 and 1974, which represents a net gain of carbon, ranging from 9.2 to 18 millions t. Finally, the methods used to calculate biospheric carbon balance and their results are compared and discussed.     

Diurnal changes in nitric oxide emissions from conventional tillage and pasture sites in the Amazon Basin: influence of soil temperature

We have investigated a subset of restoration practices applied to a degraded pasture at Fazenda Nova Vida, a 22000 ha cattle ranch in Rond^onia, Brazil. Nitric oxide (NO) and carbon dioxide (CO₂) emissions from soils were measured in conventional tillage and current pasture sites to assess N and C losses. Mean daily NO emissions from tilled plots were at least twice those from the pasture. Nitric oxide emissions from the tilled sites showed a strong diurnal pattern, while those from the pasture sites did not. Mean daytime NO emissions from the tilled sites were 9.7 g NO-N m^–2 h^–1, while mean nighttime emissions were 29.7 g NO-N m^–2 h^–1. In the pasture sites, NO emissions were 7.6 g NO-N m^–2 h^–1 during the day, and 7.7 g NO-N m^–2 h^–1 at night. Surface soil temperature was a good inverse predictor (r ²=0.75) of NO emissions from the tilled sites. Carbon dioxide emissions from the tilled sites were generally larger than CO₂ emissions from the pasture sites. The mean CO₂ emission rate from the tilled sites was 179 mg C m^–2 h^–1, while it was 123 mg C m^–2 h^–1 from the pasture sites. There was no distinct diurnal pattern for CO₂ emissions. We found that the very high temperatures measured at the soil surface in the tillage plots, in the range of 40–45°C, reduced the rate of NO emission. The reduction in NO emissions may be because of the sensitivity of autotrophic nitrifiers to high temperatures. This study provides insights on how land-use change may alter regional NO fluxes by exposing certain microbial communities to extreme environmental conditions. Future studies of NO emissions in tropical agricultural systems where soils are bare for extend periods need to make diurnal measurements or the daily fluxes will be substantially underestimated.     

Energy Intensities and Carbon Dioxide Emissions in a Social Accounting Matrix Model of the Andalusian Economy

The aim of this article is to calculate energy intensity and carbon dioxide (CO₂) emissions in Andalusia, the largest and most populated region of Spain. Energy intensities for five energy commodities used in production activities are calculated using a social accounting matrix (SAM) model with three alternative scenarios, each utilizing differing closure rules. More interestingly, by using 2005 data and updating the values of exogenous accounts, the article also provides estimates of CO₂ emissions ten years out from the 1995 base year. Finally, counterfactual experiments are performed to quantify the overall reduction in direct energy coefficients that would have made it possible to maintain constant production‐sector emissions from 1995 to 2005. The results indicate that there is a strong interdependence among energy sectors and the most intensive energy users; they also indicate the importance of induced effects when factor accounts and private consumption are endogenous. The estimates obtained concerning CO₂ emissions are close to official estimates, both from 1995 and 2005. The counterfactual experiments indicate that a 26.5% cut in the size of direct energy requirements would have made it possible to maintain constant emissions. They also indicate that efforts to curtail emissions should be focused on improving efficiency in coal extraction and combustion and oil refining.     

Species Diversity Across Nutrient Gradients: An Analysis of Resource Competition in Model Ecosystems

The capture and efficient use of limiting resources influence the competitive success of individual plant species as well as species diversity across resource gradients. In simulations, efficient nutrient acquisition or nutrient retention by species were key predictors of success when nutrients were limiting. Increased nutrient supply favored species with characteristics that improved light interception or light use. Ecological theory suggests that low diversity on fertile sites may be a consequence of competitive exclusion by one or a few species with superior light-interception characteristics. On infertile sites, competitive exclusion may be a function of superior nutrient-acquisition characteristics in species. At intermediate fertility, a shift from single-resource specialization to a balanced effort in the acquisition of multiple resources should allow for greater species diversity. Thus, a unimodal relationship between diversity and nutrient supply, vegetation biomass, or productivity is predicted. However, simulations demonstrated alternate relationships depending on the ecosystem characteristic to which diversity was compared. Diversity was greatest at intermediate total biomass but increased monotonically with net primary production and nitrogen (N) supply. The highest diversity occurred midrange on a scale of community-level leaf area to fine-root length ratios, which in the context of the model indicates that the vegetation as a whole was simultaneously limited by both N and light and that effort toward the acquisition of both resources is distributed in such a way that both resources are equally exploited. Diversity was lowered by the presence of species with a superior ability to sequester resources.     

In vitro carbon dioxide excretion from erythrocytes of two species of Antarctic fishes and its inhibition by catecholamines

This study was designed to investigate whether the blood of Pagothenia borchgrevinki , exhibits a Haldane effect, and whether activation of a Na⁺/H⁺ antiporter increases transport of intracellular protons and Bohr protons out of the erythrocytes resulting in inhibition of CO₂ excretion in both P. borchgrevinki , and Dissostichus mawsoni. When carbon dioxide dissociation curves were determined from blood samples pooled from three fish under oxygenated and deoxygenated conditions a Haldane effect was observed. Using an in vitro , CO₂ excretion assay, the rate of HCO₃⁻ dehydration was determined on blood and plasma equilibrated under an N₂atmosphere then rapidly oxygenated with air in the presence of 10⁻⁵ M noradrenaline or acetazolamide (10⁰⁴M). Whole blood and plasma from P. borchgrevinki , and D. mawsoni , were equilibrated with 0·5% CO₂ in air and assayed in the presence of 10⁻⁵ M noradrenaline. Erythrocyte CO₂ excretion rates were depressed significantly by noradrenaline in both species. The whole blood HCO₃⁻ dehydration rate was depressed significantly following rapid oxygenation in the presence of acetazolamide indicating that the pathway of CO₂ excretion included activation of intracellular carbonic anhydrase and an adrenergic receptor.     

基于解释结构模型的煤电一体化开发生态环境累积效应识别

为了对煤电一体化开发的生态环境累积效应进行识别与分析,从煤电一体化开发的主要开采建设活动、土壤环境、水资源、大气环境、生物、景观、生态7方面共筛选出29个生态环境因子,综合文献调查、专家调查问卷与访谈等方法,分析了各生态环境因子之间的相互作用关系.运用解释结构模型(ISM)分析了各因子间的关联关系与层次结构,揭示了不同开发建设活动产生累积效应的途径.结合具体的评价与管理需求,提出了煤电一体化开发生态环境累积效应研究与评估整体框架.研究结果可以为煤电一体化开发的规划与管理提供一定的理论基础与技术手段.     

Canopy Carbon Gain and Water Use: Analysis of Old-growth Conifers in the Pacific Northwest

This report summarizes our current knowledge of leaf-level physiological processes that regulate carbon gain and water loss of the dominant tree species in an old-growth forest at the Wind River Canopy Crane Research Facility. Analysis includes measurements of photosynthesis, respiration, stomatal conductance, water potential, stable carbon isotope values, and biogenic hydrocarbon emissions from Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), and western red cedar (Thuja plicata). Leaf-level information is used to scale fluxes up to the canopy to estimate gross primary production using a physiology-based process model. Both light-saturated and in situ photosynthesis exhibit pronounced vertical gradients through the canopy, but are consistently highest in Douglas-fir, intermediate in western hemlock, and lowest in western red cedar. Net photosynthesis and stomatal conductance are strongly dependent on vapor-pressure deficit in Douglas-fir, and decline through the course of a seasonal drought. Foliar respiration is similar for Douglas-fir and western hemlock, and lowest for western red cedar. Water-use efficiency varied with species and tree height, as indexed using stable carbon isotopes values for foliage. Leaf water potential is most negative for Douglas-fir and similar for western hemlock and western red cedar. Terpene fluxes from foliage equal approximately 1% of the net carbon loss from the forest. Modeled estimates based on physiological measurements show gross primary productivity (GPP) to be about 22 Mg C m^–2 y^–1. Physiological studies will be necessary to further refine estimates of stand-level carbon balance and to make long-term predictions of changes in carbon balance due to changes in forest structure, species composition, and climate.     

两种土壤含水率下匙羹藤的光合及水分利用率的初步研究

采用便携式LI-6400光合测定系统,对生长于两种土壤含水率下的当年生匙羹藤光合特性及其水分利用率进行研究。结果表明:(1)匙羹藤叶片的光饱和点(LSP)200～400μmol.m-2.s-1,光补偿点(LCP)12.1880～12.5593μmol.m-2.s-1,表观量子利用效率(α)0.0472～0.0508mol.mol-1,为阳生植物,但具有较强的弱光利用能力。(2)叶片CO2补偿点为70.97～73.75μmol.mol-1,CO2饱和点在1115.51～1687.99μmol.mol-1,羧化效率7.35×10-3～8.64×10-3μmol.m-2.s-1,表明匙羹藤为C3型植物。(3)上午10:00左右和下午4:00左右是匙羹藤水分利用率的最高时段。(4)含水率高时饱和净光合速率(Pm)、表观光合量子利用效率(α)、光饱和点都比含水率低时高,但光补偿点却比含水率低时低,说明匙羹藤利用弱光的能力较强,能有效地利用全日照的强光,光合潜力较大,生长较好;含水率低时匙羹藤的CO2补偿点较低,说明匙羹藤能利用较低的外界CO2浓度;最大水分利用效率较高,表明含水率低时匙羹藤的节水潜力较大。     

Effects of stream-crossing by a pipeline on the benthic macroinvertebrate communities of a small mountain stream

Aquatic environmental impact associated with stream-crossing by a pipeline was monitored at Archibald Creek, B.C. for two years. Water chemistry and benthic macroinvertebrates were used as monitoring tools. Results indicated that impacts arising from stream-crossing were short-term and non-residual.Funded by a contract from Canadian Arctic Gas Study Limited, calgary, to Aquatic Environments Limited, Calgary.Aquatic Environments Limited, Calgary.Aquatic Environments Limited, Calgary.     

The active uptake of carbon dioxide by the marine diatoms Phaeodactylum ticornutum and Cyclotella sp.

Mass spectromelry has been used to investigate the uptake of CO₂ by two marine diatoms, Phaeodactylum tricornutum and Cyclotella sp. The time course of CO₂ formation in the dark after addition of 100 mmol m^?3 dissolved inorganic carbon (DIC) to cell suspensions showed that external carbonic anhydrase (CA) was not present in cells of P. tricornutum but was present in Cyclotella sp. In the absence of external CA, or when it was inhibited by 5 mmol m^?3 acetazolamide, cells of both species preincubated with 100 mmol m^?3 DIG rapidly depleted almost all of the free CO₂ (3·2mmol m^?31 at pH7·5) from the suspending medium within seconds of illumination and prior to the onset of steady-state photosynthesis. Addition of bovine CA quickly restored the HCO₃^?–CO₂ equilibrium in the medium, indicating that the initial depletion of CO₂ resulted from the selective uptake of CO₂ rather than uptake of all DIG species. Transfer of cells to the dark caused a rapid increase in the CO₂ concentration in the medium, largely as a result of the efflux of unfixed inorganic carbon from the cells. The measured CO₂ uptake rates for both species accounted for 50% of the total DIG uptake at HCO₃^?–CO₂ equilibrium, indicating that HCOHCO₃^? was also being taken up. These results indicate that both Phaeodactylum tricornutum and Cyclotella sp. have the capacity to transport CO₂ actively against concentration and pH gradients.     

青藏高原高寒草甸生态系统净二氧化碳交换量特征

高寒草甸是青藏高原广泛分布的植被类型之一,面积约120万km2,地处青藏高原腹地的当雄草原站即位于该类植被的典型分布区。以2003年8~10月中旬在该站用涡度相关法连续观测的CO2通量数据资料为基础,分析了高寒草甸生态系统8~10月份净二氧化碳交换量(NEE)的日变化规律,及其与光合有效辐射、降水、温度等环境因子之间的关系。结果表明,8~10月份的日均NEE有明显的日变化,表现为单峰型,通常在地方时11:00~12:00左右达到碳吸收的最大值,平均为-0.2680mgCO2/(m2·s)(-6.0800μmolCO2/(m2·s))。白天的NEE与光合有效辐射之间符合很好的直角双曲线关系,表观量子产额平均为0.0203μmolCO2/μmolPAR,表观最大光合速率平均为9.7411μmolCO2/(m2·s)。夜晚的NEE与5cm地温有很好的指数函数关系。     

Risk Ranking of Antimicrobials in the Aquatic Environment from Human Consumption: An Irish Case Study

A mechanistic model is presented for determination of antimicrobial presence in the environment, using antimicrobial characteristics and Irish-specific usage data. The model simulates release of antimicrobials into the aquatic environment by integrating the effects of antimicrobial use, metabolism, degradation, and dilution. Predicted environmental concentrations (PECs) were ranked in relation to their potential to select for resistant bacteria, toxicity (chronic and acute), and hazard quotient (HQ). The simulated mean PECs of penicillins (PEN), β-lactams (BET), tetracyclines (TET), macrolides (MAC), quinolone/fluoroquinolones (Q/F), and sulphonamides/trimethoprim (S/T) were 1.05, 0.19, 0.06, 0.07, 0.02, and 0.08 mg/m³, respectively. All antimicrobials, excluding Q/F, showed a low HQ (<1) indicating low toxicity. Q/F had a HQ of 1.51 indicating moderate toxicity. All antimicrobial groups expressed varying resistance formation potential with Q/F having the highest. Q/F also exhibited the lowest degradation rate. A sensitivity analysis indicated a possible role for considering metabolism during regulation of new antimicrobials as this can significantly influence PEC values. The observed results suggest that current antimicrobial use can lead to levels in the environment that may increase resistance formation. The results and limitations presented here accentuate the need for further investigation into antimicrobials in the environment and contribution to resistant strains.     

艾叶超临界CO2萃取物的抑菌活性研究

本文研究了艾叶超临界CO2萃取物的抑菌活性。结果表明:艾叶超临界CO2萃取物对细菌、酵母、霉菌都有一定的抑菌作用,在酸性环境和碱性环境较为显著,对大多数细菌、酵母、霉菌的MIC不超过0.78 g/L。高温长时间处理对萃取物抑菌活性影响较大,但高温瞬时或低温处理对萃取物抑菌活性影响不大。     

Effects of Carbon dioxide on the Rheological behavior and oxygen transfer in submerged penicillin fermentations

Fermentations of Penicillium chrysogenum have been made with different CO(2) contents in the influent gas streams. The rheological behavior of the culture broth was found to be significantly changed by exposure to high levels of CO(2). This is attributed to the wide variation in the morphology of P. chrysogenum, from normal mycelia with long hyphae to roughly spherical pellets when subjected to high levels of CO(2). A correlation has been developed relating volumetric O(2) transfer coefficients, k(L)a, with the effective O(2) diffusion coefficients, D(e), and the apparent viscosities, mu(app), based on the results obtained in this study. The use of CO(2) as a potent means for altering the rheological properties of culture broths and consequently improving the O(2) transfer capabilities in penicillin fermentations was clearly demonstrated.