The applicability of different waste materials for the production of lightweight aggregates

The applicability of different waste materials for the production of lightweight aggregates has been studied. The following waste materials were investigated: silica sludge, superfluous clay in the quarry, waste glass, and residue from the polishing process of different types of stone. SiC and MnO₂ were selected as foaming agents. Feldspar containing minerals and scrap glass were added in order to lower the softening point of the waste materials. The granules were prepared by mixing together finely ground waste with one or both of the selected foaming agents. The granules were then fired at different temperatures above the softening point of the glassy phase within the temperature range from 1150 to 1220 °C, where the foaming agent degasses, and the resulting gasses remain trapped in the glassy structure. The foaming process was observed by hot-stage microscopy. The properties of the so-obtained granules, such as their apparent density and compressive strength, were determined, and their microstructures were evaluating using SEM and polarizing microscopy.With the addition to clay of polishing residue from granite-like rocks, after firing at 1220 °C homogeneously porous granules with a density down to 0.42 g/cm³ were obtained, whereas with the addition to waste silica sludge of polishing residue from granite-like rocks and waste glass with a foaming agent, after firing at 1220 °C densities from 0.57 to 0.82 g/cm³ were obtained.     

40K, 226Ra, 232Th, 238U and 137Cs relationships and behaviour in sedimentary rocks and sediments of a karstic coastal area (Kaštela Bay,Croatia) and related rocks and sediments’ differentiation

Environmental Science and Pollution Research - Natural (40K, 226Ra, 232Th, 238U) and anthropogenic (137Cs) radionuclides in consolidated sedimentary rocks (limestones s.l. and marls) and...     

Volatile fatty acid evolution in biomass mixture composts prepared in open and closed bioreactors

In this study we observed the production of volatile fatty acids (VFAs) during the composting process of compost heaps in two different bioreactors (open and closed) at three different depths (0, 40 and 80 cm). The compost was prepared as a mixture of bio-waste, horse manure, grass and sawdust to ensure sufficient pH conditions in compost heaps. VFA contents in the composting materials were analysed weekly over 14–119 d. The degradation process was monitored, along with temperature, pH, total organic carbon, oxidizable carbon and mono- and oligosaccharides. VFA contents were evaluated with regard to the depth of the sample site in the compost heap and to conditions in the bioreactors. The maximum VFA occurrence was observed during the first 35 d; acetic and propionic acids in particular were determined to occur in each sample. Considerable variations in their formation and elimination were observed in the two bioreactors as well as at the various depths in the compost heaps. Significant correlations were found between individual VFAs, as well as between VFA concentrations and organic carbon contents.     

Forest planning across Europe: the spatial scale,tools, andinter-sectoral integration in land-use planning

New approaches to forest planning are needed to support the transition of European forests to sustainable management. The aim of this study is to review forest planning systems already in place throughout Europe by exploring a set of case-study countries reflecting the main silvicultural schools of Western Europe, including Belgium, Finland, France, Italy, Portugal, and Slovenia.

A literature review and case-study data were used to assess the scale factors (vertical logic) as well as the relationships between forest planning and other environmental/land-use planning sectors (horizontal logic). The influence of EU policy on the development of forest planning is also discussed. As assessed using the vertical logic, the multi-scale and multi-topic planning approaches adopted in the countries studied here are highly heterogeneous. The horizontal logic shows that despite the importance of an inter-sectoral and harmonic relational framework between forest planning and the planning efforts of other sectors such as landscape and urban planning, the various plans are barely consistent with each other across the European countries studied here. Although interest is growing in the multi-functionality of forests, their sustainable management calls for the development of better integrated planning approaches across Europe.     

添加协效剂的灵石煤自燃阻化剂的研究

为了防止煤的自燃,采用双氧水氧化升温实验,对灵石肥煤在不同阻化剂下的阻化效果进行了研究。利用阻化时间变化率判定阻化效果。结果表明,添加氧化铝厂赤泥作为协效物质的协效阻化剂有效抑制了煤样的氧化升温,提高了阻化效果,阻化时间变化率达50.78%,为灵石肥煤最佳新型协效阻化剂。新型阻化剂原料廉价易得、反应条件温和、制备过程简单、环境友好,且实现了尾矿废渣的综合利用。     

声发射技术在湘西金矿深井安全开采中的应用

笔者介绍了岩体声发射监测技术及其基本技术参数 ,描述了井下采矿环境下识别岩体声发射信号的频谱特征 ,并进一步介绍了岩体声发射监测技术在湘西金矿深井开采中的应用情况。声发射安全监测技术应用表明 ,声发射事件率及其增长幅度直接反映了顶板稳定性的变化情况 :当岩音频度在 1 0次 /分以下时 ,采场顶板处于稳定 ;但达 1 6次 /分以上时 ,采场顶板就有冒落的可能性 ,应该采取预防措施。该技术安全监测预报结果为深井的安全生产、避免灾害事故的发生提供了决策依据     

Retrospective monitoring and inventory of soil contamination in relation to systematic monitoring

Retrospective monitoring of soil contamination has been performed in the Czech Republic. This kind of monitoring is based on the comparison of the heavy metals content in soil samples taken during a systematic soil survey (1960–1970) and in samples taken at the present time. The anticipated high degree of soil pollution in the Czech Republic has not been proved. Most of the contaminated soils were found to be loaded just 20–35 years ago. Retrospective monitoring is considered to be an accelerating tool for determining the strategy of the systematic monitoring of soil contamination. This procedure stimulated the development of the multi-step system of soil loading limits.     

Afforestation Planning and Biodiversity Conservation: Predicting Effects on Habitat Functionality in Lithuania

Habitat re-creation is one of the multiple faces of biodiversity restoration and encompasses the attempts to reconstruct an ecosystem on severely disturbed sites with little left to restore. Afforestation of abandoned or marginal agricultural land is an important tool for the re-creation of forest ecosystems and re-establishment of functional habitat networks for the maintenance of biodiversity. This study was performed in the context of the Danish-Lithuanian project ‘Afforestation of abandoned agricultural land based on sustainable land use planning and environmentally sound forest management’. The study assessed how habitat re-creation as designed in alternative afforestation plans for two administrative regions in Lithuania will affect the functionality of the landscapes for bird species of conservation concern. Spatial analysis of the forest cover was performed under existing and proposed conditions using general landscape ecological principles concerning core and edge habitats as well as nearest-neighbour metrics. The results show that the use of general criteria may result in proportionally negative changes in the availability of some forest habitats relative to changes in total forest cover, thus leading to less significant improvements in the habitats of many naturally occurring (and even protected) species compared to what would be expected from changes in forest cover alone. To solve this dilemma it is suggested that the requirements of focal species and quantitative conservation objectives should be considered in a spatially explicit – each main forest type. It is concluded that to ensure functionality of habitat networks, knowledge and experience from the fields of landscape ecology and conservation biology should be more commonly incorporated into afforestation planning.     

酸性尿素水溶液处理导弹氧化剂废水中氮氧化物

采用理论分析和实验两种方法对酸性尿素水溶液处理导弹氧化剂废水中NOx进行了研究.讨论了NO2的转化率与尿素浓度的关系.实验证明,该方法快速高效,反应的适宜温度为30 C,用7%的尿素水溶液处理含NO2 9 41 9.8 mg/m3的废水,10 s的去除率可达99.5%.