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甲烷排放源及减排对策 总被引:11,自引:0,他引:11
甲烷是一种比较重要的温室气体,它对温室效应的作用仅次于二氧化碳。据估计,目前全球每年排放的甲烷总量为535Mt,其中,通过石油与天然气工业,煤炭开采、固体废物堆存,污水处理、水稻种植、反刍家畜饲养以及生物质燃烧等人类活动排放的甲烷约占70%,根据国际能源署的有关调查与研究资料,比较系统地介绍了上述各种主要甲烷排放源及相应的减排对策。 相似文献
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The impacts of global warming on the environment, economy and society are presently receiving much attention by the international community. However, the extent to which anthropogenic factors are the main cause of global warming is still being debated. There are obviously large stakes associated with the validity of any theory since that will indicate what actions need to be taken to protect the human races only home—Earth. Most studies of global warming have investigated the rates and quantities of carbon dioxide emitted into the atmosphere since the beginning of the industrial revolution. In this paper, we focus on the earths carbon budget and the associated energy transfer between various components of the climate system. This research invokes some new concepts: (i) certain biochemical processes which strongly interact with geophysical processes in climate system; (ii) a hypothesis that internal processes in the oceans rather than in the atmosphere are at the center of global warming; (iii) chemical energy stored in biochemical processes can significantly affect ocean dynamics and therefore the climate system. Based on those concepts, we propose a new hypothesis for global warming. We also propose a revolutionary strategy to deal with global climate change and provide domestic energy security at the same time. Recent ocean exploration indicates that huge deposits of oceanic methane hydrate deposits exist on the seafloor on continental margins. Methane hydrate transforms into water and methane gas when it dissociates. So, this potentially could provide the United States with energy security if the technology for mining in the 200-mile EEZ is developed and is economically viable. Furthermore, methane hydrate is a relatively environmentally benign, clean fuel. Such technology would help industry reduce carbon dioxide emissions to the atmosphere, and thus reduce global warming by harnessing the energy from the deep sea. 相似文献
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分析在大型化学工业区建立气体中心的优点,探讨以煤为原料,以大型水煤浆气化制气为基础设置多种气体分离装置得到不 同的工业气体的工艺。初步分析该方案的优劣,为我国类似的气体供应中心提供比较依据。 相似文献
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针对高氨氮低C/N比干清粪养猪废水处理面临的脱氮问题,制作并运行了一种升流式微氧生物膜反应器(UMBR),考察了废水水质和由出水回流比调控的溶解氧(DO)对系统处理效能的影响。结果表明,将系统内DO控制在0.23~0.70 mg·L-1范围,不会对UMBR的COD去除率造成不良影响,而且能够保证NH4--N的氧化效能。但DO为0.70 mg·L-1的微氧环境,会抑制厌氧氨氧化作用,降低系统的TN去除效能。在HRT 8 h、27℃和DO 0.40 mg·L-1的条件下,UMBR对NH4--N和TN的去除负荷平均可达0.94和0.91 kg·m-3·d-1,COD去除负荷也能达到0.60 kg·m-3·d-1左右。分析认为,填料的布设及生物膜的着生,不仅保证了UMBR的微生物持有量,而且可为化能自养菌群、氨氮氧化菌群、自养反硝化菌群和异养反硝化菌群等微生物类群创造各自适宜的微环境,是系统保持污染物高效去除的生物学基础。 相似文献
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研究了氮源类型和浓度以及磷元素浓度对生物滴滤塔净化极低浓度CH4的影响。利用空气和高纯CH4混合气模拟煤矿乏风瓦斯,生物滴滤塔填料为陶瓷鲍尔环,以实验室分离筛选到的甲烷氧化菌进行接种挂膜。结果表明,进气流量为2 L?min?1,喷淋液流量为0.1 L?min?1,进气CH4浓度在0.1%~1.1%,以Na NO3为氮源时,生物滴滤塔净化CH4的效果最好,优于(NH4)2SO4和NH4NO3为氮源时的表现。喷淋液中Na NO3浓度为70 mmol?L?1,进气CH4浓度为0.1%~1.1%时,生物滴滤塔的CH4去除负荷为10.67~39.72 g?m?3?h?1,去除负荷随CH4浓度增加而增加;CH4净化率为97.92%~39.70%,净化率随CH4浓度增加而下降。在最佳氮源条件下,进气CH4浓度为0.9%,P元素浓度为100 mmol?L?1时,滴滤塔CH4去除负荷最大为49.69 g?m?3?h?1,CH4净化率60.90%。 相似文献
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《分离科学与技术》2012,47(14):3131-3153
Abstract For the separation of CH4 and CO2 from landfill gas, pure and binary adsorption behavior of these gases were studied up to 5 atmosphere pressure at 40, 70, and 100°C for silicalite as the adsorbent. Pure and binary adsorption isotherms were determined experimentally and compared to predicted isotherms by several equilibrium models, as well as the other available data in the literature. Experimental binary isotherms at different concentrations were determined by using three concentration pulse methods (CPM). HT–CPM (Harlick‐Tezel CPM) was observed to be the best one to describe the behavior of this binary system. Equilibrium phase diagrams and separation factors were obtained from the experimental binary isotherms. For this system, the integral thermodynamic consistency tests were also shown and discussed. 相似文献
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Alyaa K. Mageed;May Ali Alsaffar;Mohamed Abdel Rahman Abdel Ghany;Khalid A. Sukkar;Bamidele Victor Ayodele; 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2024,99(12):2655-2664
The mitigation of global warming effect requires intensified research efforts to reduce greenhouse gas emissions. This study was aimed at investigating the valorization of two principal greenhouse gases, namely carbon dioxide (CO2) and methane (CH4), over CeO2-doped Co–Ni/GO catalytic materials. The CeO2-doped Co–Ni/GO catalysts were synthesized using a sequential wet impregnation method and employed for CO2 reforming of CH4. The catalytic materials were characterized using various instrumental techniques. Response surface methodology (RSM) was employed to investigate the impact of process factors, namely reaction temperature (ranging from 700 to 800 °C), CeO2 loading (ranging from 5% to 15%) and feed flowrate (ranging from 10n to 50 mL min−1), on the CH4 conversions. 相似文献
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Geovanni Avila-Nuñez;Alexis Saldivar;Patricia Ruiz-Ruiz;Sergio Revah; 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2024,99(6):1356-1363
Methanotrophs play an important role in mitigating methane (CH4) emissions in ecosystems. They closely interact with other microorganisms forming communities where the cross-feeding of metabolites, presumably methanol (MeOH), is essential for the growth and activity of non-methanotrophs. The experiments in this study were focused on investigating the effect of adding the supernatant from a methanotrophic consortium to pure cultures of Methylomonas methanica. 相似文献
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The significance of agricultural sources of greenhouse gases 总被引:17,自引:0,他引:17
John M. Duxbury 《Nutrient Cycling in Agroecosystems》1994,38(2):151-163
The impact of development of land for agriculture and agricultural production practices on emissions of greenhouse gases is reviewed and evaluated within the context of anthropogenic radiative forcing of climate. Combined, these activities are estimated to contribute about 25%, 65%, and 90% of total anthropogenic emissions of CO2, CH4, and N2O, respectively. Agriculture is also a significant contributor to global emissions of NH3, CO, and NO. Over the last 150 y, cumulative emissions of CO2 associated with land clearing for agriculture are comparable to those from combustion of fossil fuel, but the latter is the major source of CO2 at present and is projected to become more dominant in the future. Ruminant animals, rice paddies, and biomass burning are principal agricultural sources of CH4, and oxidation of CH4 by aerobic soils has been reduced by perturbations to natural N cycles. Agricultural sources of N2O have probably been substantially underestimated due to incomplete analysis of increased N flows in the environment, especially via NH3 volatilization from animal manures, leaching of NO
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, and increased use of biological N fixation.The contribution of agriculture to radiative forcing of climate is analyzed using data from the Intergovernmental Panel on Climate Change (IPCC)(base case) and cases where the global warming potential of CH4, and agricultural emissions of N2O are doubled. With these scenarios, agriculture, including land clearing, is estimated to contribute between 28–33% of the radiative forcing created over the next 100yr by 1990 anthropogenic emissions of CO2, CH4, and N2O. Analyses of the sources of agriculturally generated radiative climate forcing show that 80% is associated with tropical agriculture and that two-thirds comes from non-soil sources of greenhouse gases. The importance of agriculture to radiative forcing created by different countries varies widely and is illustrated by comparisons between the USA, India, and Brazil. Some caveats to these analyses include inadequate evaluations of the net greenhouse effects of agroecosystems, uncertainties in global fluxes of greenhouse gases, and incomplete understanding of tropospheric chemical processes.Extension of the analytical approach to projected future emissions of greenhouse gases (IPCC moderate growth scenario) indicates that agriculture will become a less important source of radiative forcing in the future. Technological approaches to mitigation of agricultural sources of greenhouse gases will probably focus on CH4 and N2O because emissions of CO2 are essentially associated with the socio-political issue of tropical deforestation. Available technologies include dietary supplements to reduce CH4 production by ruminant animals and various means of improving fertilizer N management to reduce N2O emissions. Increased storage of C in soil organic matter is not considered to be viable because of slow accretion rates and misconceptions about losses of soil organic matter from agricultural soils. 相似文献
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A global inventory of nitric oxide emissions from soils 总被引:15,自引:1,他引:15
Over 60 published papers reporting field measurements of emissions of nitric oxide (NO) from soil are reviewed, and over 100 annual estimates of NO emissions were made for various types of ecosystems, including agricultural fields. These data were stratified by biome and the mean of each stratum was multiplied by an estimate of the biome area. A few strata were identified as clearly having low NO emissions: montane forests, swamps and marshes, tundra, and temperate forests that are not heavily affected by N deposition. The largest emissions were observed in tropical savanna/woodland, chaparral, and cultivated agriculture, but variation in NO emissions within these strata was also large. Although the stratification scheme fails to partition this within-stratum variation, it does clearly identify these biomes as globally important sources of NO and as areas where more research is needed to investigate within-biome variation in NO emissions. It is too early to tell whether differences in NO emissions between temperate and tropical agriculture are significant, but it is clear that agriculture is an important source of NO and that management practices affect NO emissions. The best current estimate of the global soil source of NO is 21 Tg N yr-1. Adsorption of NOx onto plant canopy surfaces may reduce emissions to the atmosphere to as low as 13 Tg N yr-1, although the absorption effect is probably smaller than this. An error term for the global estimate is difficult to determine, but it is at least ±4 and perhaps as large at ±10 Tg N yr-1. Hence, only modest progress has been made in narrowing uncertainties in the estimate of the global soil source of NO, although some published lower estimates appear unlikely. This inventory reconfirms that the soil source of NO is similar in magnitude to fossil fuel emissions of NOx. Further narrowing of the uncertainty of the estimate of global soil NO emissions will require more sophisticated and carefully chosen stratification schemes to address variation within biomes based on soil fertility, soil texture, climate, and management and will require linking this type of inventory and stratification with mechanistic models. 相似文献
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文章针对目益严熏的猪场养殖业排放物污染问题,构建于清粪工艺、水葫芦生态稳定塘、沼气池、种植业为基础的生态处理系统。监测结果显示,处理效果明显,投入成本低廉、不形成二次污染,适用在广大农村地区进行应用和推广。 相似文献
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CaO/PAC混合絮凝剂的沼液净化性能 总被引:2,自引:0,他引:2
厌氧发酵后产生的沼液中含有大量的有机污染物需要处理,为降低后期沼液处理工程的操作费用,改善常规絮凝剂存在的不足,本文提出向沼液中添加由氧化钙(CaO)和聚合氯化铝(PAC)组成的混合絮凝剂对沼液进行预处理,降低沼液浊度、化学需氧量(COD)和总磷(TP)质量浓度,以及强化沼液的氨氮脱除潜力,并研究了混合絮凝剂中CaO和PAC的添加顺序、质量浓度配比和总质量浓度的影响。结果表明,CaO/PAC混合絮凝剂中CaO和PAC的添加顺序对沼液净化性能的影响并不显著。降低CaO/PAC中CaO与PAC的质量浓度配比(mCaO/mPAC)和增加CaO/PAC总质量浓度均将会降低沼液浊度、COD含量与TP质量浓度,但以沼液pH来表征的沼液氨氮脱除潜能却随着mCaO/mPAC值与CaO/PAC总质量浓度的上升而增加。综合考虑混合絮凝剂对沼液的净化性能,CaO/PAC混合絮凝剂总质量浓度可选择12.5~18.75g/L,mCaO/mPAC值可选择(2~10)∶1。 相似文献
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Interactions and coupling between emissions of methane and nitrous oxide from animal husbandry 总被引:1,自引:0,他引:1
G.J. Monteny C.M. Groenestein M.A. Hilhorst 《Nutrient Cycling in Agroecosystems》2001,60(1-3):123-132
The gases methane (CH4) and nitrous oxide (N2O) contribute to global warming, while N2O also affects the ozone layer. Sources of greenhouse gas emissions in animal husbandry include animals, animal houses (indoor
storage of animal excreta), outdoor storage, manure and slurry treatment (e.g., composting, anaerobic treatment), land application
and chemical fertilisers. Although in many countries emphasis is put on reduction of environmental pollution by nutrients,
ammonia emission and odour nuisance, reduction of the emission of greenhouse gases will become equally important in the near
future to meet integrated sustainability criteria (1997 Kyoto protocol). Emissions of greenhouse gases differ in origin. Methane
from animal husbandry is for a large part endogenous, and may be hard to reduce in intensive animal production. Methane emission
reduction strategies should focus on its use as fuel or preventing its formation, mainly during on-farm storage (indoor, outside)
or treatment through control of critical processes (degradation of organic matter) and critical factors (e.g., temperature).
Nitrous oxide is mainly produced during the aerobic storage and treatment of animal excreta, as well as after land spreading.
As N2O basically is an intermediate product of complex biochemical processes (nitrification, denitrification), optimal process
conditions are the key issues in N2O emission reduction strategies from animal husbandry.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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John H. Seinfeld 《American Institute of Chemical Engineers》2011,57(12):3259-3284
The global temperature increase over the last century and a half (~ 0.8°C), and the last three decades in particular, is well outside of that which can be attributed to natural climate fluctuations. The increase of atmospheric CO2 over this period has been conclusively demonstrated to be a result largely of fossil fuel burning. The global mean temperature change that results in response to a sustained perturbation of the Earth's energy balance after a time sufficiently long for both the atmosphere and oceans to come to thermal equilibrium is termed the Earth's climate sensitivity. The purely radiative (blackbody) warming from a doubling of CO2 from its preindustrial level of 280 parts‐per‐million (ppm) to 560 ppm is ~ 1.2°C; the actual warming that would result is considerably larger owing to amplification by climate feedbacks, including that owing to water vapor. Increases in greenhouse gas (GHG) levels are estimated to have contributed about +3.0 W m?2 perturbation (radiative forcing) to the Earth's energy balance. Particles (aerosols), on the whole, exert a cooling effect on climate, with a total forcing estimated by the Intergovernmental Panel on Climate Change (2007)1 as ?1.2 W m?2, a value that is subject to considerable uncertainty. If the actual magnitude of aerosol forcing is close to the low end of its estimated uncertainty range, then it offsets a considerably smaller fraction of the GHG forcing and the total net forcing is at the high end of its range, ~ 2.4 W m?2; at the other extreme, if the actual aerosol cooling is at the high end of its range, then aerosol forcing is currently offsetting a major fraction of GHG forcing, and the total net forcing is only ~ 0.6 W m?2. To explain the actual global increase in temperature of ~ 0.8°C, these two extremes have major implications in terms of the Earth's climate sensitivity. Climate sensitivity is determined by the strength of feedbacks, of which cloud feedback is the most uncertain. That the Earth has warmed and that GHGs are responsible is unequivocal; the Earth's climate sensitivity and the effect of aerosols complicate answers to the question: how much warming and how soon? © 2011 American Institute of Chemical Engineers AIChE J, 2011 相似文献
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综述了温室气体效应的功过及其变化和人类活动对自然大气温室效应的影响以及地球本身所存在的应对全球变暖的一些恢复能力;陈述了对于温室气体及其效应,我国已采取的种种应对之策;阐述了扭转温室气体效应逐渐变大的危险须全人类联手才行。 相似文献