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电厂燃煤过程中汞控制技术研究 总被引:3,自引:0,他引:3
燃煤电厂汞控制技术分燃烧前、燃烧中和燃烧后脱汞,燃烧后脱汞技术为主要汞控制排放工艺,其中吸附剂吸附方法的研究较为广泛。基于国内外近几年燃煤电厂烟气脱汞技术的研究,综述了汞控制技术的最新进展。 相似文献
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介绍了燃煤电厂汞控制研究现状,分析了燃煤中汞的含量和赋存状态、燃烧中汞的化学行为特性,探讨了汞的监测和控制技术,为我国燃烧电厂汞排放控制提供参考. 相似文献
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K. Karlfeldt Fedje S. Rauch P. Cho B.-M. Steenari 《Waste management (New York, N.Y.)》2010,30(7):1273-1279
The incineration of MSW in fluidized beds is a commonly applied waste management practice. The composition of the ashes produced in a fluidized bed boiler has important environmental implications as potentially toxic trace elements may be associated with ash particles and it is therefore essential to determine the mechanisms controlling the association of trace elements to ash particles, including the role of major element composition. The research presented here uses micro-analytical techniques to study the distribution of major and trace elements and determine the importance of affinity-based binding mechanisms in separate cyclone ash particles from MSW combustion. Particle size and the occurrence of Ca and Fe were found to be important factors for the binding of trace elements to ash particles, but the binding largely depends on random associations based on the presence of a particle when trace elements condensate in the flue gas. 相似文献
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Khudre M. Attar B.S. Tawabini E.R. Pambid M.A. Abdel-Aal 《Waste management (New York, N.Y.)》1991,11(4)
Leachate from composite samples of automobile-scrap shredder waste was analyzed for trace elements by inductively coupled plasma atomic emission spectrometry, according to the USEPA Toxicity Characteristic Leaching Procedure for solid waste (TCLP). Analytical results confirmed the existence of several environmentally important elements such as barium, cadmium, copper and lead. However, the concentrations of these elements were below the USEPA regulatory limits for the leachate of solid waste. It was also found that representative average values for trace elements, as well as their variability in the leachate of such heterogeneous solid waste, can be arrived at by analyzing composite samples rather than single samples, if a stratified sample selection and composition plan were implemented. Effect of extraction fluids used in the TCLP method was also investigated. The results indicated that the more acidic extraction fluid can leach more of the elements from the shredder waste, regardless of the selection criterion specified in the method. 相似文献
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Thermodynamic analysis of the role of chlorine and sulfur environments during combustion and incineration processes 总被引:1,自引:0,他引:1
Iddi S.N. Mkilaha Hong Yao Ichiro Naruse 《Journal of Material Cycles and Waste Management》2002,4(2):143-149
In order to control the emission of trace metals from combustion and incineration systems, sorbents and filters are sometimes
used. However, the effectiveness of these methods is greatly affected by the volatility of the metals and the way in which
they speciate during combustion, and afterwards during condensation, and physical or chemical sorption. Although there has
been a lot of research into the mechanisms by which trace metals speciate and subsequently appear in submicron particles,
the details of these mechanisms are not yet thoroughly understood. In this study, a chemical equilibrium approach was used
to qualitatively determine the speciation of lead, cadmium, and chromium in Cl and S environments. The reaction conditions
of sorbents were also tested numerically in order to understand the reaction behavior of metals with sorbents. This article
reports the influence of different concentrations of Cl and SO2 on Pb, Cd, and Cr speciation, as representatives of other trace elements. The partitioning behavior of metals during combustion
was also examined for Cl and S. The results obtained indicate that most metals exist in the vapor phase, even at low temperatures,
when chlorine is present. However, the addition of SO2 enhances the formation of the condensed phase, except at extremely high temperatures. This observation was not significant
for Cd or Cr. The higher the concentration of Cl the higher the retention of trace metals in the vapor phase, even at low
temperatures. Results from comparisons of the reactivities of mixed metals with Cl indicate that the presence of Fe limits
the reactivity of most trace metals with Cl except at higher concentrations. In the presence of Fe, alkali metals are the
first to react with Cl. If Fe is not present, most trace metals react with Cl, and the activity increases with higher concentrations.
On the other hand, the partitioning characteristics of S show that its presence generally means that metals remain in the
condensed phase. Sulfur is more reactive with alkali metals than with other trace metals.
Received: June 6, 2001 / Accepted: April 30, 2002 相似文献
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Matthias Achternbosch Klaus-Rainer Br?utigam Nicola Hartlieb Christel Kupsch Ulf Richers Peter Stemmermann 《Waste management & research》2005,23(4):328-337
The results of model calculations carried out to identify and quantify the input pathways of trace elements into cement and concrete and to estimate the extent to which trace element concentrations in cement may change due to waste utilization are presented. As expected, primary raw materials represented the most important input pathway for trace elements into cement, but the contribution from wastes was not negligible. The use of waste led to a slight increase of the concentrations of cadmium, antimony and zinc in cement. For cobalt, lead and vanadium, this increase was less distinct and for all other trace elements considered, the effect of the use of wastes on trace element concentrations in cement could not be demonstrated clearly. The trace element content of concrete was governed by the aggregates for most elements considered. However, for arsenic, cadmium, lead and zinc, both cement and the additive coal fly ash contributed noticeably to the total trace element concentration in the concrete. 相似文献
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A mobile sampling and measurement system for the analysis of gaseous and liquid samples in the field was developed. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is built into a van, was used as detector. The analytical system was calibrated with liquid and/or gaseous standards. It was shown that identical mass flows of either gaseous or liquid standards resulted in identical ICP-OES signal intensities. In a field measurement campaign trace and minor elements in the raw flue gas of a waste wood combustor were monitored. Sampling was performed with a highly transport efficient liquid quench system, which allowed to observe temporal variations in the elemental process gas composition. After a change in feedstock an immediate change of the element concentrations in the flue gas was detected. A comparison of the average element concentrations during the combustion of the two feedstocks showed a high reproducibility for matrix elements that are expected to be present in similar concentrations. On the other hand elements that showed strong differences in their concentration in the feedstock were also represented by a higher concentration in the flue gas. Following the temporal variations of different elements revealed strong correlations between a number of elements, such as chlorine with sodium, potassium and zinc, as well as arsenic with lead, and calcium with strontium. 相似文献
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The purpose of this study was to examine if long-term anaerobic digestion of food waste in a semi-continuous single-stage reactor could be stabilized by supplementing trace elements. Contrary to the failure of anaerobic digestion of food waste alone, stable anaerobic digestion of food waste was achieved for 368 days by supplementing trace elements. Under the conditions of OLR (organic loading rates) of 2.19-6.64 g VS (volatile solid)/L day and 20-30 days of HRT (hydraulic retention time), a high methane yield (352-450 mL CH(4)/g VS(added)) was obtained, and no significant accumulation of volatile fatty acids was observed. The subsequent investigation on effects of individual trace elements (Co, Fe, Mo and Ni) showed that iron was essential for maintaining stable methane production. These results proved that the food waste used in this study was deficient in trace elements. 相似文献
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针对工业废水难生物降解的问题,综述了通过添加微量营养物质影响活性污泥法处理难降解工业废水效果的研究进展,介绍了微量营养物质的分类,总结了微量金属元素和维生素等不同种类微量营养物质及其适宜浓度对微生物生长的作用以及对污泥法处理难降解工业废水效果的影响。指出:补充必要的微量营养物质是提高难降解工业废水处理效果的可行的优化策略,但是需要针对工业废水可生化性和营养需求的特点有的放矢地进行补充;另外需要对各种微量营养物质促进污染物降解的代谢途径进行研究。 相似文献
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Yooko Tsuchiya Hisashi Abe Hisashi Shimogaki 《Journal of Material Cycles and Waste Management》2011,13(2):150-155
The leaching properties of trace elements in wood ash were examined to evaluate the safety of using woody biomass ash. Boron
and selenium were detected in high concentrations not only in ash collected from an electric furnace but also in combustion
ash from a small wood stove. As for the leaching of trace elements, the influence of calcium compounds on boron and selenium
in wood ash is proposed. The leaching of trace elements is enhanced when calcium carbonate is the calcium compound in ash,
although it is inhibited in the case of portlandite. There is little information in the literature that can be used to determine
the effective use of wood biomass ash, thus limiting the development of woody biomass for applications such as thermal power
generation. 相似文献