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1.
高温固硫反应中锶化合物的促进作用   总被引:18,自引:0,他引:18  
肖佩林  沈迪新 《环境化学》1994,13(5):389-394
本文论述了锶化合物在高温燃烧条件下固硫反应的促进作用,通过X-射线粉晶衍射及扫描电镜的研究,证明形成含硫酸钙的复合盐的生成是提高固硫率的关键,用该方法制成的工业型煤,在实际锅炉中试烧其固硫率可达70%,是烟气排烟脱硫的有效方法之一,对净化大气,减少污染有现实意义。  相似文献   

2.
煤气发生炉在工业炉窑烟气治理中的应用   总被引:2,自引:0,他引:2  
文章介绍了煤气发生炉在工业炉窑烟气治理中的应用,从减少环境污染和节能降耗两个方面客观实际地分析了不同的煤气发生炉在各种窑炉应用中的特点,对典型性和普遍性的内容予以概括,希望起到抛砖引玉的作用,以利用工业炉窑烟气治理工程的开展。  相似文献   

3.
选择性去除香烟烟气中亚硝胺的研究   总被引:15,自引:0,他引:15  
沸石具有选择性吸附和催化去除亚硝胺的功能.使用沸石添加剂和/或微波辐射预处理,可将香烟侧流烟气中致癌性物质亚硝胺的含量降低约50%,主流烟气中降低60-90%,能有效地减轻吸烟对于环境的污染.  相似文献   

4.
高效湿式脱硫除尘一体化装置的研究   总被引:3,自引:0,他引:3  
针对我国目前SO2和颗粒状污染物(特别是PM10)污染严重的现状,开发了一种高效湿式除尘脱硫一体化装置。试验表明,本装置的平均除尘率和平均脱硫率分别为97.6%和88.1%。并且对细小颗粒物具有良好的捕集效果。与国内同类装置比较,本装置能在较小的液气比(0.11-0.34L/m^3)和阻力(<900MPa)条件下实现良好的除尘和脱硫,适合于工业锅炉和窑炉的烟气治理。  相似文献   

5.
文章综述了国内烟气脱硫技术及设备发展的历程和现状,分析了引进国外全套烟气脱硫技术装置对国内用户所造成的巨大经济压力,提出走转化高新技术发展国内烟气脱硫技术的道路,介绍了国内外脱硫技术与国内技术相结合,在天津市重点工程项目上实施的实例。  相似文献   

6.
燃煤烟气中汞形态分析的实验研究   总被引:5,自引:0,他引:5  
在一维煤粉燃烧炉台架上采用EPA推荐的Ontario Hydro方法 ,测量了燃烧不同煤种排放的烟气中汞的形态分布情况 .结果表明 ,烟气中汞以颗粒态和气态汞的形式存在 .气态汞总量在 9— 2 3 μg·Nm- 3范围内 ,主要以单质汞的形式存在 ,占气态汞总量的 5 2 %—83 % ,而二价汞占 1 7%— 48% .飞灰中汞的浓度大大超过了底灰中汞的浓度 ,表明汞在飞灰中富集 ,在底灰中分散的行为  相似文献   

7.
改性半焦烟气脱硫的机理研究   总被引:10,自引:0,他引:10  
刘昌见  李荫重 《环境化学》1999,18(4):309-314
本文对海拉尔褐煤半焦及其水蒸气活化和高温氧化改性后的烟气脱硫性能进行了研究。  相似文献   

8.
一步法烟气浸锰-脱硫的工艺参数及机理   总被引:1,自引:1,他引:0  
应用一步法烟气浸锰-脱硫的新工艺,考察烟气流量、烟气SO2浓度、吸收时间、液固比及浸出时间等工艺参数对烟气氧化脱硫效果的影响,并运用溶液化学原理,对SO2及Mn2 在溶液中的组分进行了计算,研究Mn2 液相催化氧化烟气脱硫的机理.在吸收液pH值5-6时,锰主要以Mn2 形态存在,Mn2 的存在强化了从HSO-3开始发生的SO2氧化反应.采用菱锰矿为原料,能有效地脱除含SO2烟气中的硫,在实现烟气脱硫的同时自动调节溶液的pH值,并可从浸出液中回收高价值的硫酸锰.在最佳的工艺条件下,仅一步吸收过程,取得了锰浸出率85%,含SO2烟气脱硫率70%以上的效果.  相似文献   

9.
固定燃烧源排放N2O的采样,分析方法及其监测   总被引:5,自引:1,他引:5  
赵瑞兰  赵海涛 《环境化学》1995,14(2):113-117
烟道气是一含有多种哗合物的复杂体系,除N2,O2外,还含有燃烧产物H2O,CO2CO,NOx,SO2和H2S等,烟气样在贮放过程中它们之间相互影响,使各自的浓度发生变化,为了得到烟气中N2O含量的准确测定值,分别研究了H2O,SO2和NO的含量,放置时间对N2O生成量的影响,试验结果表明,玻璃注射器不适于贮放烟气样,样品中只有H2O,SO2和NO三种化合物同时存在时,才会有进一步的N2O的生成,其  相似文献   

10.
杨法军  赵保路 《环境化学》1993,12(2):116-120
本文用ESR自旋捕集技术,以4-POBN为捕集剂,研究了吸烟烟气处理的鼠肝微粒体体系中的自由基性质。结果发现,在吸烟烟气处理的鼠肝微粒体中,4-POBN捕集到了自由基信号,这一信号的强度随温育时间的延长及充入烟气的量增加而增强,根据其性质及ESR波谱参数分析,体系中产生了脂类自由基。结果说明,吸烟烟气刺激了鼠肝微粒体的脂质过氧化。  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

14.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

15.
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.  相似文献   

16.
17.
Parasitic wasps orient to green leaf volatiles   总被引:12,自引:0,他引:12  
Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture  相似文献   

18.
Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras  相似文献   

19.
The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.  相似文献   

20.
International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).  相似文献   

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