湿法烟气脱硫添加剂的试验研究

采用我校自主设计研制的水浴脱硫设备,以石灰石为脱硫剂,通过模拟烟气净化冷态模型试验研究了甲酸,乙酸,已二酸,草酸作为有机添加剂对湿法烟气脱硫的影响,并讨论了其机理.试验结果表明,有机酸添加剂能减缓脱硫液pH值的降低过程,能在较低的pH值时得到较高的脱硫率.实验结果为有机添加剂在湿法脱硫中的应用提供了理论依据.     

Assessing Land-Use Impacts on Natural Resources

/ Much information is available on changes that occur in natural resources from both spatially-explicit data on environmental conditions and models of the interactions of these conditions and resources with human activities. The strategy for assessing land-use impacts on natural resources developed in this paper provides a framework for using relevant data and models to address questions of how management practices can promote both use and protection of resources. This assessment strategy integrates spatially explicit environmental data using geographic information systems (GIS) with computer models that simulate changes in land cover in response to land-use impacts. The computer models also simulate susceptibility of species to changes in habitat suitability and landscape patterns. The approach is applied to management of limestone barrens on the Oak Ridge Reservation in East Tennessee. Potential limestone barrens habitats are identified by overlaying appropriate soils, geology, slope, and land-use/land-cover conditions. Their validity is tested against known sites containing rare species that occur in these habitats. The location of habitats at risk in the aftermath of human activities is determined by using an available area model that identifies the size and proximity of sites that particular types of species can no longer use as habitat. The resulting risk map can be used in land management planning. The approach uses readily available in situ and remotely sensed data and is applicable to a wide range of locations and land-use scenarios. This approach can be refined based on needs identified by land managers and on the sensitivity of the results to the resolution of available resource information.KEY WORDS: Land management; Assessment; Habitat characterization; Limestone barrens; Ecological modeling; Geographic information systems     

Slope,aspect and climate: Spatially explicit and implicit models of topographic microclimate in chalk grassland

The slope and aspect of a vegetated surface strongly affects the amount of solar radiation intercepted by that surface. Solar radiation is the dominant component of the surface energy balance and influences ecologically critical factors of microclimate, including near-surface temperatures, evaporative demand and soil moisture content. It also determines the exposure of vegetation to photosynthetically active and ultra-violet wavelengths. Spatial variation in slope and aspect is therefore a key determinant of vegetation pattern, species distribution and ecosystem processes in many environments. Slope and aspect angle may vary considerably over distances of a few metres, and fine-scale species’ distribution patterns frequently follow these topographic patterns. The availability of suitable microclimate at such scales may be critical for the response of species distributions to climatic change at much larger spatial scales. However, quantifying the relevant microclimatic gradients is not straightforward, as the potential variation in solar radiation flux under clear-sky conditions is modified by local and regional variations in cloud cover, and interacts with long-wave radiation exchange, local meteorology and surface characteristics.     

湿壁塔烟气脱硫系统的研究

湿壁塔为基础的石灰石湿法烟气脱硫系统，以６０ｍ＾３／ｈ的模拟烟气的中试设备来研究该系统的操作特性（液气比Ｌ／Ｇ；石灰石浓度；喷雾状态；填料结构等）与脱硫率的关系，并得到了较为满意的工艺参数。     

无机盐对SO2—H2O—CaCO3气液固三相反应系统pH值的影响

研究了硫酸钠、硝酸钠和氯化钠及相应钙盐对石灰石浆液烟气脱硫条件下ＳＯ２－Ｈ２Ｏ－ＣａＣＯ３气、液、固三相反应系统中ｐＨ值的影响。发现硫酸钠能明显提高系统的ｐＨ值，硝酸钠和氯化钠使ｐＨ值提高的幅度不大，而３种钙盐均使ｐＨ值降低。根据膜模型的分析结果，认为无机盐影响该反应系统ｐＨ值的主要原因是无机盐的加入改变了石灰石表面的ｐＨ值。     

粉煤灰处理煤矿酸性废水的研究

采用石灰石中和沉淀，粉煤灰吸附处理煤矿酸性废水，取得了良好的效果。用石灰石调节pH至4.5，再用石灰中和至中性，并用粉煤灰吸附，粉煤灰用量为10g／L时处理效果较好。     

Limestone surfaces in built-up environment as indicators of atmospheric pollution

The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a black particle count (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO₂ and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels.     

石灰石脱硫反应动力学研究

用热重分析法（TGA）研究了石灰石脱硫反应特性,得出了影响氧化钙转化率的各种因素,包括反应温度、石灰石粒径、SO₂浓度和反应时间等。对反应机理进行分析并建立了反应动力学模型。     

石灰与石灰石作湿法脱硫剂的比较

石灰、石灰石是最常用的湿法脱硫剂。从反应机理、运行控制指标、液气比和钙硫比（化学过量比）、浆液循环池等方面对其性能作了比较。两者的脱硫机理、运行控制指标不同,受温度的影响程度也不同。两系统的最小液气比分别为10．0和5．6,化学过量比分别为1．05～1．15和1．25～1．60。前者的脱硫效力优于后者。     

粉煤灰对脱硫用石灰石溶解特性的影响研究

石灰石-石膏湿法烟气脱硫是我国广泛应用的脱硫技术,其中石灰石（CaCO3）活性对优化脱硫装置的设计,降低脱硫成本,提高脱硫效率显得尤为重要。通过实验对CaCO,活性进行了研究,在固定pH值的条件下,采用酸滴定CaCO3浆液的方法,研究了不同pH值以及粉煤灰对CaCO3溶解率的影响。结果表明,在所测的pH值范围内,较低的pH值有利于CaCO3的溶解,pH值每降低0．5,CaCO3的溶解率增加8％左右。但为了保持吸收溶液的脱硫效果,一般选择pH值=5．0～5．5之间。粉煤灰对石灰石硫酸溶解的影响较小,初始2h内粉煤灰对CaCO3的溶解有较大的促进作用,2h后变为微弱的阻碍作用。