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烟气脱硝技术及在我国的应用 总被引:3,自引:0,他引:3
氮氧化物气体是危害最大、最难处理的大气污染物之一。随着经济的发展,有效控制燃煤造成的大气污染已经刻不容缓,特别是控制燃煤过程中的氮氧化物,烟气脱硝技术显得相当重要。本文分析了几种常用的烟气脱硝技术(选择性催化还原脱硝技术、选择性非催化还原脱硝技术、碱性溶液吸收法和等离子体活化法等)的原理、技术特点以及在我国的应用情况。 相似文献
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介绍了垃圾焚烧烟气烧脱硝控制的主要技术及应用情况,以及非催化还原技术的应用实例,采用该技术,氮氧化物排放值可满足现阶段排放要求。 相似文献
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燃煤烟气中的氮氧化物(NOX)脱除,国际上主要采用SCR法,但SCE催化剂制备工艺技术是制约我国脱硝技术产业化的瓶颈。对催化剂配方和成型工艺进行优化和创新研制的TZ型板式催化剂填补了国内空白。 相似文献
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选择性催化还原法(SCR)是目前国际上处理火电厂氮氧化物的最主要方法.本文从SCR工艺的原理出发,介绍了与德国STEULER公司在烟气脱硝技术方面合作的相关运行工艺. 相似文献
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Despite the importance of anhydrous ammonia (AA) and urea as nitrogen (N) fertilizer sources in the United States, there have been few direct comparisons of their effects on soil nitrous oxide (NO) and nitric oxide (NO) emissions. We compared N oxide emissions, yields, and N fertilizer recovery efficiency (NFRE) in a corn ( L.) production system that used three different fertilizer practices: urea that was broadcast and incorporated (BU) and AA that was injected at a conventional depth (0.20 m) (AAc) and at a shallower depth (0.10 m) (AAs). Averaged over 2 yr in an irrigated loamy sand in Minnesota, growing season NO emissions increased in the order BU < AAc < AAs. In contrast, NO emissions were greater with BU than with AAc or AAs. Emissions of NO ranged from 0.5 to 1.4 kg N ha (50-140 g N Mg grain), while NO emissions ranged from 0.2 to 0.7 kg N ha (20-70 g N Mg grain). Emissions of total N oxides (NO + NO) increased in the order AAc < BU < AAs. Despite having the greatest emissions of NO and total N oxides, the AAs treatment had greater NFRE compared with the AAc treatment. These results provide additional evidence that AA emits more NO, but less NO, than broadcast urea and show that practices to reduce NO emissions do not always improve N use efficiency. 相似文献
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Erich Wagner 《Environmental management》1994,18(5):759-765
Environmental management involves controlling various forms of pollution to levels that do not pose a threat to the health
of the people and the environment in general. This paper presents a framework to analyze sources of local air pollution in
cities. Using an OLS model, an investigation is performed of the relationship among the concentrations of air pollutants [more
precisely, concentrations of sulfur dioxide (SO2), dust, nitric oxide (NO), nitrogen dioxide (NO2), carbon oxide (CO) and ozone (O3)], economic activities, and meteorology. Time series analysis leads to a model, that explains a high degree of the variance
in the air pollution data. The model is applied to daily time series from three measurement stations in innsbruck, Austria.
Estimation results of the model generally fit with the expected relations. Space heating influences SO2, dust, and NO, while NO2 levels are primarily affected by traffic. These results also indicate interdependent relations among the pollutants NO, NO2, O3, and CO; O3 levels depend on temperature and sunshine. 相似文献
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Nitrification and denitrification gene abundances in swine wastewater anaerobic lagoons 总被引:2,自引:0,他引:2
Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling ofN is only beginning to become understood. Within this cycling, nitrification can be performed by organisms that produce the enzyme ammonia monooxygenase. For denitrification, the reduction of nitrite to nitric oxide can be catalyzed by two forms of nitrite reductases, and N,O can be reduced by nitrous oxide reductase encoded by the gene nosZ The objectives of this investigation were to (i) quantify the abundance of the amoA, nirK, nirS, and nosZ genes; (ii) evaluate the influence of environmental conditions on their abundances; and (iii) evaluate their abundance relative to denitrification enzyme activity (DEA). Samples were analyzed via real-time quantitative polymerase chain reaction and collected from eight typical, commercial anaerobic, swine wastewater lagoons located in the Carolinas. The four genes assayed in this study were present in all eight lagoons. Their abundances relative to total bacterial populations were 0.04% (amoA), 1.33% (nirS), 5.29% (nirK), and 0.27% (nosZ). When compared with lagoon chemical characteristics, amoA and nirK correlated with several measured variables. Neither nirS nor nosZ correlated with any measured environmental variables. Although no gene measured in this study correlated with actual or potential DEA, nosZ copy numbers did correlate with the disparity between actual and potential DEA. Phylogenetic analysis ofnosZdid not reveal any correlations to DEA rates. As with other investigations, analyses of these genes provide useful insight while revealing the underlying greater complexity of N cycling within swine waste lagoons. 相似文献
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Nitrogen oxide and methane emissions under varying tillage and fertilizer management 总被引:6,自引:0,他引:6
Comprehensive assessment of the total greenhouse gas (GHG) budget of reduced tillage agricultural systems must consider emissions of nitrous oxide (N2O) and methane (CH4), each of which have higher global warming potentials than carbon dioxide (CO2). Tillage intensity may also impact nitric oxide (NO) emissions, which can have various environmental and agronomic impacts. In 2003 and 2004, we used chambers to measure N2O, CH4, and NO fluxes from plots that had been managed under differing tillage intensity since 1991. The effect of tillage on non-CO2 GHG emissions varied, in both magnitude and direction, depending on fertilizer practices. Emissions of N2O following broadcast urea (BU) application were higher under no till (NT) and conservation tillage (CsT) compared to conventional tillage (CT). In contrast, following anhydrous ammonia (AA) injection, N2O emissions were higher under CT and CsT compared to NT. Emissions following surface urea ammonium nitrate (UAN) application did not vary with tillage. Total growing season non-CO2 GHG emissions were equivalent to CO2 emissions of 0.15 to 1.9 Mg CO2 ha(-1) yr(-1) or 0.04 to 0.53 Mg soil-C ha(-1) yr(-1). Emissions of N2O from AA-amended plots were two to four times greater than UAN- and BU-amended plots. Total NO + N2O losses in the UAN treatment were approximately 50% lower than AA and BU. This study demonstrates that N2O emissions can represent a substantial component of the total GHG budget of reduced tillage systems, and that interactions between fertilizer and tillage practices can be important in controlling non-CO2 GHG emissions. 相似文献
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Increased knowledge of the magnetic field influence on hemodynamic function may have significant therapeutic potential and
possible health effects. For example, magnetic field therapy using moderate intensity static magnetic fields (SMF) in the
mT range (in particular, 1–600 mT) could be useful for circulatory diseases, including ischemic pain, inflammation, and hypertension,
primarily due to the modulation of blood flow and/or blood pressure through the nervous system. We suggested that the mechanisms
of SMF effects on the circulatory system in the mT range could be mediated by suppressing or enhancing the action of biochemical
effectors, thereby inducing homeostatic effects biphasically. The potent mechanisms of SMF effects have often been linked
to nitric oxide pathway, Ca2+-dependent pathway, sympathetic nervous system (e.g., BRS and the action of sympathetic agonists or antagonists), and neurohumoral
regulatory system (e.g., production and secretion of angiotensin II and aldosterone). Thus, this review mainly focuses on
the experimental studies of SMF effects on the circulatory system in animals and may provide the physiological basis for future
clinical investigations of SMF therapy. 相似文献
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Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material – Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing. 相似文献
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This research work investigates the engine performances, combustion characteristics, and emission of exhaust gases of variable compression ratio engine fuelled with cottonseed oil methyl ester (COME) and diesel at different blends. The analysis showed that heat release rate and cylinder pressure is higher for diesel than COME blends. Higher BTE is obtained at the maximum load condition. The higher BTE and lower SFC are obtained for blend B15 as 42.17% and 0.2 kg/kW-hr at brake mean effective pressure (BMEP) of 4.64 bar. Also it is found that the peak cylinder gas pressure and combustion duration increases when the BMEP increases. At the BMEP of 3.51 bar, higher HRR is observed as 18.12 J/deg. Increase in HRR is obtained as 6.07% for B30 at BMEP of 4.64 bar when compared to diesel. Ignition delay decreased by 13.16% for B100, by the increment of blend proportions when compared to diesel, at BMEP of 4.64 bar. Lower smoke, HC and CO emissions are observed when increasing the blend proportions, whereas the nitric oxide emissions increases due to the better combustion resulted in higher temperatures. At BMEP of 4.64 bar, the CO emissions are reduced to 25.24% for neat biodiesel when compared with the diesel. 相似文献
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采用消化液硝酸/高氯酸消解法、硝酸-硫酸消解法和微波消解方法消化省沽油,用原子吸收分光光度法测定硒(Se)含量。比较了3种消解方法在测定省沽油中的硒含量。发现微波消解法测定野生省沽油(干菜)中Se含量准确性好、时间段效率高、对环境污染少、操作简单。 相似文献
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D.R. Quigley J.E. Wey C.R. Breckenridge D.L. Stoner 《Resources, Conservation and Recycling》1988,1(3-4)
Solubilization of nitric acid oxidized Texas lignite by either microorganisms or alkali were compared. Three fungi and three actinomycetes were able to solubilize small amounts of 3.2 N nitric acid-oxidized coal in liquid culture. A correlation was observed between increases in culture fluid pH and solubilization. Extraction of 8 N nitric acid-oxidized Texas lignite with alkaline buffers (pH 7, 8, 10, 11, and 12.3) resulted in extensive coal solubilization. UV-Vis spectra of most microbially solubilized samples were similar to those of alkali solubilized coal. Addition of alkali soluble Texas lignite to growing cultures resulted in no UV-Vis spectral changes with time for the majority of cultures tested. Taken together these data suggest that alkali production is a mechanism by which microorganisms solubilize oxidized coal. 相似文献
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通过对某民爆企业废气排放现状进行分析发现,该厂废气主要来源于稀硝酸配制产生的硝烟和粉尘、硫化氢、爆炸烟气、硝烟、一甲胺的无组织排放。针对该企业废气排放现状,提出了采用新建硝烟吸收罐对稀硝酸配制过程中产生的硝烟进行吸收处理和拟采用碱液吸收系统对产生的硫化氢气体进行处理等治理措施。 相似文献