固化/稳定化处理污泥填埋气液转化模式

固化/稳定化污泥进行填埋产生填埋气,产气规律是指导填埋气收集处理系统设计的重要依据。通过构建大型填埋柱模拟填埋实验,研究不同固化材料添加量污泥气液转化规律。实验结果表明,原泥和固化污泥产气规律分为2种类型:前期产气速率呈线性增加,达到最大速率后产气速率呈指数降低。低添加量的固化污泥,产气分3个阶段,分别为产气抑制期、增长期和衰减期。高添加量固化污泥,产气只有一个阶段,产气速率随着时间推移逐渐减小,产气量很小。固化污泥降解过程就是有机质含量降低,气体产量、含水率增加相互转化过程,达到固化材料添加量25%时,水分和气体产生量均很小,降解受到很强抑制,产气150 d左右稳定,产气量很小,无需单独设置气体收集系统。     

Biotechnologies and bioinspired materials for the construction industry: an overview

Looking back to less than three centuries of industrialization, responsible for alarming levels of pollution and consumption of non-renewable resources that has led to the exhaustion of the earth's capacity, the humankind only now begins to grasp the overwhelming potential of natural systems. During almost 40 million centuries, Nature has developed materials and processes with optimal performance which are totally biodegradable. Analysis of bioinspired materials requires the knowledge of both biological and engineering principles which are being a part of a large research area termed biotechnology. This hot area is one of the six strategic Key Enabling Technologies that will be funded under the EU Framework Programme Horizon 2020. This paper reviews the current knowledge on the potential of this emerging field, particularly in the development of materials and technologies for the construction industry. It covers the use of bacteria for enhancing concrete durability and for soil stabilization. It also covers bioinspired tough composite materials, bioinspired adhesives and coatings, and self-cleaning materials. Incorporation of biology basics in the civil engineering curriculum would ease the communication between biologists and civil engineers, helping to foster research on biotechnologies and bioinspired materials for the construction industry.     

Even low to medium nitrogen deposition impacts vegetation of dry, coastal dunes around the Baltic Sea

Coastal dunes around the Baltic Sea have received small amounts of atmospheric nitrogen and are rather pristine ecosystems in this respect. In 19 investigated dune sites the atmospheric wet nitrogen deposition is 3-8 kg N ha⁻¹ yr⁻¹. The nitrogen content of Cladonia portentosa appeared to be a suitable biomonitor of these low to medium deposition levels. Comparison with EMEP-deposition data showed that Cladonia reflects the deposition history of the last 3-6 years. With increasing nitrogen load, we observed a shift from lichen-rich short grass vegetation towards species-poor vegetation dominated by the tall graminoid Carex arenaria. Plant species richness per field site, however, does not decrease directly with these low to medium N deposition loads, but with change in vegetation composition. Critical loads for acidic, dry coastal dunes might be lower than previously thought, in the range of 4-6 kg N ha⁻¹ yr⁻¹ wet deposition.     

Influence of papermill sludge on growth of Medicago sativa, Festuca rubra and Agropyron trachycaulum in gold mine tailings: a greenhouse study

A greenhouse study was undertaken to determine the suitability of adding papermill sludge to neutral/alkaline gold mine tailings to improve the establishment of Festuca rubra, Agropyron trachycaulum and Medicago sativa. Festuca rubra root and shoot biomass and A. Trachycaulum shoot biomass were increased with papermill sludge amendment. The addition of papermill sludge and fertilizer drastically increased the shoot and root biomass of M. sativa (20-30 times) while A. trachycaulum and F. rubra showed a more moderate increase in growth. Photosynthetic pigment content of the leaves was higher in papermill sludge treatments than in the treatments without papermill sludge. The organic carbon content, macro-aggregate content and field capacity of the gold mine tailings were increased while the bulk density was decreased by the addition of papermill sludge. This study suggests that addition of papermill sludge and adequate fertilization can alleviate some of the adverse conditions of neutral/alkaline gold mine tailings.     

流化床飞灰固化焚烧飞灰效果及微观分析

以深圳某垃圾焚烧厂焚烧飞灰为例分析了焚烧飞灰的性质和重金属毒性.结果表明,飞灰中 Pb 和 Cr 超出TCLP 阈值,必须进行稳定化处理.以流化床飞灰为主要成分配制固化材料,按不同比例掺人焚烧l￡灰进行固化实验,结果表明,实验范围内重金属固定效果良好.微观测试显示,固化过程主要产物有水化硅酸钙凝胶、钙矾石等,通过物理包胶、物理吸附、复分解沉淀反应和同晶替代等作用抑制重金属浸出.     

含油污泥生物稳定的研究进展

生物法处理含油污泥,已经成为国内外石油化行业的研究热点。本文综述了含油污泥的来源、生物稳定化原理,介绍了生物稳定的主要研究技术和应用进展,指出利用生物方法对含油污泥实现无害化和资源化,具有处理效果好、运行费用低、可资源化利用、不产生二次污染等优点,是国内外含油污泥处理处置的发展趋势。     

Ecological effects of cultivation on the machair sand dune systems of the Outer Hebrides, Scotland

The machair sand dune systems of the Outer Hebrides of Scotland are a unique habitat, which is rare within both a global and European context. Unusually, the machair habitat also represents an agricultural resource that is very important to the Hebridean people, having been subject to both grazing and cultivation throughout the historical period. Following designation as an Environmentally Sensitive Area (ESA) in 1988, the machairs of South Uist have been studied with the aim of understanding the links between agricultural practice and their plant community and ecosystem dynamics. This research focused primarily on the effects of cultivation practices and their role in maintaining plant species richness and community and ecosystem stability. Within two carefully selected areas, the successional plant communities of machair at different stages of recovery following ploughing and cultivation of cereals and potato patches or ‘lazy beds’ were identified at both a macro- and micro-level. Investigations of the vegetation recovery processes on turves taken from newly ploughed land indicated that the initial stages of recolonization are characterized primarily by rapid vegetative reproduction and growth, although re-vegetation by seeds is also an important factor. The implications of these findings for the long-term management of machair plant communities are discussed and in particular the need to maintain old cultivation practices such as shallow ploughing. The need for more detailed research into both seed banks and seed rain and into processes of vegetative reproduction is stressed.