Heavy metals in flue gas cleaning residue

During combustion, most of the inorganic nutrients and trace elements in the fuel are retained and enriched in the ash. However, here we show that, due to the low total heavy metal concentrations, the flue gas cleaning residue (i.e. the fly ash) originating from the wet scrubber device at a medium-sized (32 MW) municipal district heating plant, is a potential forest fertilizer. Furthermore, the easily soluble calcium (1,980 mg kg⁻¹; d.w.) and phosphorus (50 mg kg⁻¹; d.w.) concentrations indicate that the flue gas cleaning residue is a potential agent for soil remediation and for improving soil fertility.     

Long-term exposure to enhanced UV-B radiation has no significant effects on growth or secondary compounds of outdoor-grown Scots pine and Norway spruce seedlings

The effects of long-term enhanced UV-B radiation on growth and secondary compounds of two conifer species were studied in an outdoor experiment. Scots pine (Pinus sylvestris) seedlings were exposed for two growing seasons and Norway spruce (Picea abies) seedlings for three growing seasons to supplemental UV-B radiation, corresponding to a 30% increase in ambient UV-B radiation. The experiment also included appropriate controls for ambient and increased UV-A radiation. Enhanced UV-B did not affect the growth of the conifer seedlings. In addition, neither the concentrations of terpenes and phenolics in the needles nor the concentrations of terpenes in the wood were affected. However, in the UV-A control treatment the concentrations of diterpenes in the wood of Scots pine decreased significantly compared to the ambient control. Apparently, a small increase in UV-B radiation has no significant effects on the secondary compounds and growth of Scots pine and Norway spruce seedlings.     

Macroalgal communities face the challenge of changing biotic interactions: review with focus on the Baltic Sea

In diverse littoral communities, biotic interactions play an important role in community regulation. This article reviews how eutrophication modifies biotic interactions in littoral macroalgal communities. Eutrophication causes blooms of opportunistic algae, increases epibiotism, and affects regulation by grazers. Opportunistic algae and epibionts harm colonization and growth of perennial algae. Grazing regulates the density and species composition of macroalgal communities, especially at the early stage of algal colonization. Eutrophication supports higher grazer densities by increasing the availability and quality of algae to grazers. This may, on the one hand, enhance the capability of grazers to regulate and counteract the increase of harmful, bloom-forming macroalgae; on the other hand, it may increase grazing pressure on perennial species, with a poor tolerance of grazing. In highly eutrophic conditions, bloom-forming algae may also escape grazing control and accumulate. Increasing epibiotism and grazing threaten in particular the persistence of habitat-forming perennials such as the bladderwrack. An interesting property of biotic interactions is that they do not remain fixed but are able to evolve, as the traits of the interacting species adapt to each other and to abiotic conditions. The potential of plants and grazers to adapt is crucial to their chances to survive in changing environment.     

Prenatal detection of hydrolethalus syndrome

The prenatal diagnosis of hydrolethalus syndrome is presented on the basis of seven cases. The results demonstrate the primary importance of ultrasonography in the evaluation of this type of malformation. Already in early pregnancy, the intracranial abnormalities and the accelerated growth rate of the fetal head are demonstrable by ultrasound more easily than in ordinary ‘simple’ hydrocephalus. Diagnostic amnioncentesis in early pregnancy proved to be useless because alpha-feto-protein levels and chromosomal status were normal.     

Chemical determinants of resistance in winter-dormant seedlings of European white birch (Betula pendula) to browsing by the mountain hare

Summary A sample of one-year-old seedlings of European white birch (Betula pendula) was analyzed to determine the content of sugars, phenolics and terpenoid compounds. Two vertical segments of each seedling were analyzed separately. The number of resin droplets, which correlates strongly and negatively with feeding by the mountain hare, was also counted on the bark of experimental seedlings. The variation in the palatability of birch seedlings to mountain hare was determined primarily by the most abundant terpenoid, papyriferic acid. On the other hand, the resistance to hare feeding at the seedling bases, which are frequently attacked by voles, appeared to be dependent on other components, apparently phenolic substances. Sugars did not affect the resistance of the tested seedlings. The variation among experimental seedlings was much greater for secondary substances, especially terpenoid compounds, than for sugars. It is suggested that this high variation in protective compounds may be an adaptive trait selected for by the feeding of generalist herbivores.     

Interference by wood ant influences size selection and retrieval rate of prey by Formica fusca

Summary Dominance relations between the territorial wood ant Formica polyctena and the submissive F. fusca generate testable predictions on the mechanisms of their coexistence. Here I tested the influence of interference competition by the dominant F. polyctena on the foraging of F. fusca. In the presence of F. polyctena, the activity and the retrieval rate of items of F. fusca decreased significantly. When F. fusca were given a choice between small chironomids and flies a hundred times heavier they selected nearly always flies in the absence of wood ants; when disturbed F. fusca took proportionately more chironomids. In nature, irrespective of distance from the wood-ant mound the size distribution of potentially available food items was the same. F. fusca collected smaller items close to the wood-ant mound, where the density of interfering wood ants was high, than far from it. Also, F. polyctena carried larger protein items from the outskirts of its territory than from the center. The items of F. fusca were on average smaller than those of F. polyctena although the item-size overlap was substantial. When encountering a F. polyctena, those F. fusca workers carrying a fly always lost their booty to the dominant but always managed to bring the chironomids to the nest. F. fusca and F. polyctena were equally efficient in detecting single chironomids placed on the surface of ground, but the presence of either species decreased the discovery rate of the other. This implies mutual exploitation competition between the species for the locally most abundant protein resource. F. polyctena found single flies faster than F. fusca. In an earlier study I showed that close to the wood-ant mound the colony size and production of sexual offspring of F. fusca were reduced. I suggest that the suppressed colony success of F. fusca is attributable to the diminished size and decreased retrieval rate of prey items close to the woodant mound abounding with interfering wood-ant foragers.     

Cost-Effectiveness of Alternative Strategies in Mitigating the Greenhouse Impact of Waste Management in Three Communities of Different Size

Waste management is a significant source of methane (CH₄) emissions. CH₄ is second to carbon dioxide (CO₂) the most important anthropogenic greenhouse gas. In this article the methodology and results from a study on the reduction potential of alternative waste treatment strategies in mitigating the greenhouse impact are presented. The objective is to provide information to decision makers so that the greenhouse issue can be included in the decision making on waste management strategies. The potential cost-effectiveness of reducing the greenhouse impact of alternative waste treatment strategies in three communities of different size in Finland is assessed. The estimation of the greenhouse impact includes estimates of the greenhouse gas (GHG) emissions, the amount of carbon (C) stored at landfills (Csink) and the emission savings that can be achieved by using waste for energy production (assumed decrease in the use of fossil fuels). Landfill gas recovery with energy production was found to be the most-efficient way in reducing the greenhouse impact from large landfills. Burning of all the waste or the combustible fraction in municipal solid waste (MSW) was also an efficient method to reduce greenhouse gas emissions, especially if the energy produced can reduce the burning of fossil fuels. Emissions from transportation of waste are small compared with the emissions from landfills. Even if the transportion mileage is doubled due to increasing separation and recycling the greenhouse impact of transportation would be only 3–4 percent of the impact of landfilling the waste.     

波罗的海蓝藻赤潮的历史

波罗的海所发生的赤湖,主要是由Nodudaria spupmigena和Aphanizomenon sp.这两种蓝藻形成的.有关这些赤潮的长期变化记录可以从过去(1887～1938年)和现代(1974～1998年)出版的浮游植物数据记录中找到.通过各种不同的收集、分析方法已经得到了大量的数据,为了提高这些数据的可比性,人们正在不断地尝试老的、新的采样方式与固定方法.l00多年前,浮游生物就做为鱼类的食物来源而引起了人们的兴趣;富营养化问题主要出现在南部的礁湖(haffs)以及大城市附近的海边水ro域.二战前,很少有关于开阔海域赤潮的报道.在过去的营养环境中,Nodudaria spupmlgena和Aphanizomenon sp.的数量还很少,从l 887～1938年的137个夏季采样中表明它们的丰度还没有达到过最高峰.在现在的营养环境中,高丰度是非常普遍的,这两个物种的数目范围相对于过去的营养环境来说有了明显的增长.自20世纪60年代以来,蓝藻赤潮在波罗的海本体与芬兰湾的开阔海域是非常常见的,这表明了营养物已经高度丰富.     

Cost-Effectiveness of Alternative Strategies in Mitigating the Greenhouse Impact of Waste Management in Three Communities of Different Size

Mitigation and Adaptation Strategies for Global Change - Waste management is a significant source of methane (CH4) emissions. CH4 is second to carbon dioxide (CO2) the most important anthropogenic...     

Mitigation of global greenhouse gas emissions from waste: conclusions and strategies from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. Working Group III (Mitigation).

Greenhouse gas (GHG) emissions from post-consumer waste and wastewater are a small contributor (about 3%) to total global anthropogenic GHG emissions. Emissions for 2004-2005 totalled 1.4 Gt CO2-eq year(-1) relative to total emissions from all sectors of 49 Gt CO2-eq year(-1) [including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and F-gases normalized according to their 100-year global warming potentials (GWP)]. The CH4 from landfills and wastewater collectively accounted for about 90% of waste sector emissions, or about 18% of global anthropogenic methane emissions (which were about 14% of the global total in 2004). Wastewater N2O and CO2 from the incineration of waste containing fossil carbon (plastics; synthetic textiles) are minor sources. Due to the wide range of mature technologies that can mitigate GHG emissions from waste and provide public health, environmental protection, and sustainable development co-benefits, existing waste management practices can provide effective mitigation of GHG emissions from this sector. Current mitigation technologies include landfill gas recovery, improved landfill practices, and engineered wastewater management. In addition, significant GHG generation is avoided through controlled composting, state-of-the-art incineration, and expanded sanitation coverage. Reduced waste generation and the exploitation of energy from waste (landfill gas, incineration, anaerobic digester biogas) produce an indirect reduction of GHG emissions through the conservation of raw materials, improved energy and resource efficiency, and fossil fuel avoidance. Flexible strategies and financial incentives can expand waste management options to achieve GHG mitigation goals; local technology decisions are influenced by a variety of factors such as waste quantity and characteristics, cost and financing issues, infrastructure requirements including available land area, collection and transport considerations, and regulatory constraints. Existing studies on mitigation potentials and costs for the waste sector tend to focus on landfill CH4 as the baseline. The commercial recovery of landfill CH4 as a source of renewable energy has been practised at full scale since 1975 and currently exceeds 105 Mt CO2-eq year(-1). Although landfill CH4 emissions from developed countries have been largely stabilized, emissions from developing countries are increasing as more controlled (anaerobic) landfilling practices are implemented; these emissions could be reduced by accelerating the introduction of engineered gas recovery, increasing rates of waste minimization and recycling, and implementing alternative waste management strategies provided they are affordable, effective, and sustainable. Aided by Kyoto mechanisms such as the Clean Development Mechanism (CDM) and Joint Implementation (JI), the total global economic mitigation potential for reducing waste sector emissions in 2030 is estimated to be > 1000 Mt CO2-eq (or 70% of estimated emissions) at costs below 100 US$ t(-1) CO2-eq year(-1). An estimated 20-30% of projected emissions for 2030 can be reduced at negative cost and 30-50% at costs < 20 US$ t(-) CO2-eq year(-1). As landfills produce CH4 for several decades, incineration and composting are complementary mitigation measures to landfill gas recovery in the short- to medium-term--at the present time, there are > 130 Mt waste year(-1) incinerated at more than 600 plants. Current uncertainties with respect to emissions and mitigation potentials could be reduced by more consistent national definitions, coordinated international data collection, standardized data analysis, field validation of models, and consistent application of life-cycle assessment tools inclusive of fossil fuel offsets.