电-袋复合除尘器功效探究

针对当前认为电-袋复合除尘器是一种新的除尘技术的观点,分析探讨了目前国内采用的电-袋复合除尘器的功效,指出电-袋复合除尘器实际为前电后袋式的电-袋结合除尘器,因而存在许多弊端,并不能克服电除尘器和袋式除尘器各自的缺点。     

电袋复合除尘器在燃煤锅炉大型机组上的应用

近年来,电袋复合除尘技术在燃煤锅炉烟气除尘行业的应用取得了快速发展,并实现了600MW、1000MW大型机组的突破。电袋复合除尘器已成为继电除尘器、袋式除尘器之后的新一代高效除尘设备。应用实践表明,电袋复合除尘器对煤种变化的适应性强,可长期保持低排放,并具有运行阻力低、占地面积小等优点。介绍了世界上首台1000MW机组电袋复合除尘器的开发和应用情况。     

复合除尘技术在烧结机电除尘器改造中的应用

简要介绍了电袋复合除尘器的技术特点及其在烧结机机尾旧电除尘器改造中的应用。电袋复合除尘器集合了电除尘器和布袋除尘器的优点,除尘效率高,系统运行阻力低,滤袋使用寿命长,应用于旧电除尘器的改造,具有良好的经济效益和环保效益。     

电-袋复合式除尘器运行管理探讨

针对电-袋复合式除尘器的特点,分析了电-袋复合式除尘器在运行过程中应注意的事项,提出了电-袋复合式除尘工艺过程的运行管理要求,探讨了电-袋复合除尘器设备管理以及现场运行参数的设定,以实现提高电-袋复合式除尘器使用寿命及降低能耗的目的。     

大型燃煤机组配套除尘设备的技术经济性分析

目前国家批建的火力发电燃煤机组主要为600MW及以上的大型机组,结合新的粉尘浓度≤30mg/Nm3的排放标准要求,本文根据大型燃煤机组主流配套的三种高效除尘设备(电除尘器、袋式除尘器、电袋复合除尘器)的设计经验,对其技术经济性进行了对比分析,结果表明,电袋复合除尘器的综合技术经济性优势明显。     

燃煤电厂电-袋复合除尘器滤袋损坏原因分析

着重对电-袋复合除尘器存在的PPS滤袋短期内出现非寿命期大面积损坏的原因,以及针对电-袋复合除尘工艺技术中的部分不同意见,进行了进一步的分析和探讨;提出电-袋复合除尘器与袋式除尘器在技术经济上并没有特殊优势,且电-袋复合除尘器在应用中已发现了一些重大问题,因而应引起有关重视,在选择采用这种工艺技术时要慎重。     

金属纤维电袋复合除尘器在氧化铝厂的应用

金属纤维电袋复合除尘器结合了传统电除尘器和袋除尘器的优点,是一种新型的耐高温、耐腐蚀、高过滤精度、低阻力的工业除尘净化设备,可实现高温烟气粉尘的超低排放。文章介绍了金属纤维电袋复合除尘器的结构、特点,并结合实际工程应用,说明了金属纤维电袋复合除尘器可实现氢氧化铝焙烧炉尾部烟气的超低排放,可在氧化铝厂推广应用。     

电袋除尘器的发展与机理研究

随着国家对细微颗粒物的排放标准要求日趋严格,除尘技术也在不断发展与改进。电袋除尘器是将静电除尘器和布袋除尘器有机结合起来的新型除尘设备,能有效提高除尘效率,降低压力损失。文章对电袋除尘器的发展历程进行了回顾,对其工作原理及除尘机理进行了分析研究,旨在为电袋除尘器的发展及推广提供一定参考。     

大型超净电袋复合除尘技术在土耳其的应用

以出口首台实现烟尘超低排放的土耳其泽塔斯三期2×660MW机组超净电袋复合除尘器为研究对象,分析超净电袋复合除尘技术的原理和措施,并介绍了该工程的工艺方案,通过运行情况、测试结果及电厂反馈,证明超净电袋复合除尘技术大型化出口应用的可行性和稳定性。     

高温超净电袋复合除尘器在氧化铝行业的应用

文章对比了在超低排放背景下的各种除尘技术对氢氧化铝〔Al(OH)_3〕焙烧炉烟气净化的适应性,提出了其最佳可行技术,即高温超净电袋复合除尘技术,阐述了该技术的原理及特点,重点介绍了山东某厂1#炉3000t/d Al(OH)_3焙烧炉项目电除尘器改造配套采用高温超净电袋复合除尘器技术方案,性能测试结果表明经改造出口颗粒物的排放浓度小于5mg/Nm~3,达到超低排放的要求。该技术的成功应用,验证了其除尘效率高、运行阻力小、维护费用低、无二次污染等优点,可大幅提高副产物回收率,降低除尘设备电耗,减少排污费,具有良好的经济效益和社会效益。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

Surface applied water treatment residuals affect bioavailable phosphorus losses in Florida sands

Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.     

Animal Consciousness and Ethics in Asia and the Pacific

The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. This revised version was published online in July 2006 with corrections to the Cover Date.     

Rehabilitation and Flood Management Planning in a Steep,Boulder-Bedded Stream

This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects.     

AN INDEX FOR MEASURING THE PERFORMANCE OF IRRIGATION MANAGEMENT SYSTEMS WITH AN APPLICATION1

ABSTRACT: This paper presents a statistically valid index for measuring the performance of irrigation systems. The index is applied to a sample of 39 farms on a watercourse under the warabandi system of irrigation management in India. It is found that while the farmers in fact irrigated almost exactly the total amount of irrigated area as designed, inter-farm variations were considerable. The index shows that the degree of error of managerial effectiveness of irrigation on this watercourse is 20 percent. Therefore it is concluded that the system is performing at 80 percent effectiveness.     

WATER LOSS EQUATIONS AND COEFFICIENTS TO ESTIMATE RUNOFF FROM RAINFALL1

Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found.     

Vegetation dynamics in impounded marshes along the Indian River Lagoon,Florida, USA

Data are presented on the vegetation dynamics of two impounded marshes along the Indian River Lagoon, in east-central Florida, USA. Vegetation in one of the marshes (IRC 12) was totally eliminated by overflooding and by hypersaline conditions (salinities over 100 ppt) that developed there in 1979 after the culvert connecting the marsh with the lagoon was closed. Over 20% recovery of the herbaceous halophytesSalicornia virginica, S. bigelovii, andBatis maritima was observed at that site after the culvert was reopened in 1982, but total cover in the marsh remains well below the original 75%. No recovery of mangroves was observed at this site. The second site (SLC 24), while remaining isolated from the lagoon during much of the study, did not suffer the complete elimination of vegetation experienced at the first site. At this location, mangroves increased in cover and frequency with a concomitant decrease in herbaceous halophytes. Considerable damage to the vegetation was evident at IRC 12 when the impoundment was closed and flooded for mosquito control in 1986. Although the damage was temporary, its occurrence emphasizes the need of planning and constant monitoring and adjustment of management details as conditions within particular marshes change. Storms and hurricanes may be important in promoting a replacement of black mangroves by red mangroves in closed impoundments because the former cannot tolerate pneumatophore submergence for long periods of time. University of Florida-IFAS Journal Series R-00521.