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81.
Uncertainties in Solubility Calculations 总被引:1,自引:0,他引:1
Summary. When considering the possible migration of hazardous elements in groundwater, one has to take into account several phenomena,
e.g. solubility, ion exchange, adsorption, matrix diffusion, and transport paths. Here, we focus upon the solubility which in
turn depends on several more or less uncertain chemical properties. Uncertainties in the data during laboratory experiments
aiming at measurements of thermodynamic constants may cause uncertainties in the amount of some species of several tenths
of the relative mass fraction.
The thermodynamic data may then be used for solubility calculations under different conditions and water compositions. Clearly,
there are several uncertainties associated with solubility calculations in the rock-water system. First, there is the effect
of uncertainties in thermodynamic data such as stability and solubility constants, and also enthalpies of reaction if the
water is not at room temperature. Furthermore, there are the rock-water interactions which will change the water composition
as different minerals come in contact with the water flowing through a system of fractures. Studies in mineralogy to an accuracy
good enough for modeling of water evolution are difficult to perform, and therefore the mineral composition of the rock and
thus the water composition should be treated as parameters subjected to uncertainties. In addition, there are also conceptual
uncertainties with respect to input data. The calculation of a solubility should be an easy task for every chemist, but in
fact results differing by orders of magnitude are found even when the modelers have used the same computer program and the
same data.
In this paper, uncertainties associated with solubility calculations are discussed. The results are exemplified on the calculated
solubilities of some actinides in groundwater from crystalline rock.
Received August 21, 2000. Accepted (revised) May 18, 2001 相似文献
82.
毛细管区带电泳分离测定邻、对、间氯代苯酚 总被引:3,自引:0,他引:3
通过改变电泳条件,用毛细管区带电泳成功地分离了邻、对、间氯代苯酚,并检测到废水中样品的含量。研究了缓冲溶液种类、浓度、pH值、电泳电压以及内标物的选择,并得出了三种样品的标准曲线、线性范围以及加样回收率,为环境样品的监测提供了依据。 相似文献
83.
84.
以改性废旧聚苯乙烯塑料高效减水增强剂为基的早强型水泥高效减水剂的研究 总被引:4,自引:0,他引:4
以自己改性合成的改性聚苯乙烯塑料高效减水增强剂为基础 ,利用调配技术 ,与水泥早强剂、普通减水剂复配制备综合性能优良的早强型高效减水剂。研究了配方中各组分对水泥混凝土性能如早期强度、减水率和最终强度的影响 相似文献
85.
利用焦炭和铁屑在酸性含铬溶液中形成接触电池,使六价铬转化为三价铬,再在碱性液中把三价铬沉淀析出的方法,采用简单的设施对电镀厂含铬废水进行处理,以较少的投入达到国家废水排放标准。 相似文献
86.
Cristiana Lofrumento Marilena Ricci Elena Platania Maurizio Becucci Emilio Castellucci 《Journal of Raman spectroscopy : JRS》2013,44(1):47-54
Micro‐Raman spectroscopy has been widely employed in the last few years for the study of artworks, allowing for the characterization of a high class of pictorial materials. However, the detection of organic dyes by conventional Raman spectroscopy is quite difficult, due to the high fluorescence provided by these compounds. Recently, remarkable improvements have been achieved by the introduction of the surface enhanced Raman spectroscopy (SERS) technique for the analysis of organic dyes. In the present work, a new method is presented, based on the use of a SERS probe made of agar‐agar coupled with silver nanoparticles, for a non‐destructive and minimally invasive micro‐extraction of dyes from textiles. Ag‐agar gel has been tested first on textile mock‐ups dyed with alizarin, purpurin and carminic acid. SERS measurements have been performed adopting laser light excitations at 514.5 and 785 nm of a micro‐Raman setup. Highly structured SERS band intensities have been obtained. After having verified the safety of the method by colorimetric, X‐ray fluorescence and attenuated total reflectance Fourier transform infrared techniques, a real case, a pre‐Columbian piece of textile, have been investigated by Ag‐agar gel. This cutting‐edge method offers new possibilities for a sensitive and non‐destructive analysis of fluorescent materials. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
87.
Innovative stabilization/solidification processes of fly ash from an incinerator plant of urban solid waste 总被引:3,自引:0,他引:3
R. Fuoco A. Ceccarini P. Tassone Y. Wei A. Brongo S. Francesconi 《Microchemical Journal》2005,79(1-2):29
Fly ash samples from an incineration plant of urban solid waste (USW) were submitted to a stabilization/solidification process based on encapsulation with a polyester resin. With this process, a very limited increase of about 25% in weight and a compressive strength as high as 1200 kg/cm2 can be obtained. The efficiency of the process to stabilize/solidify the residues and to reduce the pollutant release was evaluated by performing both mechanical and leaching tests following the IRSA–CNR standard method. The leaching test was based on treating the sample with an acetic acid solution adjusted to pH 5.2 for 24 h under magnetic stirring. Toxic metals (Pb, Cd, and Cu) and organic pollutants (PAHs, PCBs, and OCPs) were determined in raw fly ash samples and in the leaching solutions of treated samples. Raw residues showed higher concentrations of trace metals than the regulatory limits, whereas the stabilized/solidified residues showed a concentration of all the pollutants lower than the regulatory limits and a compressive strength much higher than the suggested minimum value. Finally, a critical comparison with conventional stabilization/solidification processes based on the use of Portland cement highlighted that the polyester resin-based process performed much better in terms of the release of both organic and inorganic pollutants, thus substantially lowering the environmental impact of these residues. 相似文献
88.
现代流行的能源管理方面的软件多是利用字符型数据库系统进行对能源数据的统计分析并生成电子报表山。余热资源量的计算涉及不多。这项工作恰恰是能源管理系统中难度较大问题之一。其主要原因是能源转换和耗能设备种类繁多、运行工况复杂多变、现场能源监测数据不全、计算工作量大的缘故。对余热资源量的计算和分析要投入大量的精力和财力。因此,开发余热资源量的计算和统计分析的应用软件是非常必要的。11业余热载体的种类及其余热资源量的计算方法1.1工业余热资源分类工业余热资源按载热体形态可分为三大类:固态载体余热资源、液态载体… 相似文献
89.
Langmaier F. Mládek M. Kolomaznik K. Šívarová J. Sukop S. 《Journal of Thermal Analysis and Calorimetry》2002,67(3):659-666
Hydrolysates from chromed leather waste obtained in powdered form on an industrial scale by using biotechnical methods were
analysed by TG an DSC techniques. Besides about 9% (mass/mass) of moisture, around 1% (mass/mass) of cyclohexylamine was found
in the pulverized hydrolysates. Calorimetric measurement of the reaction heats of the reactions of the hydrolysates with commercially
available aldehydes indicates that their reactivity decreases in the sequenceglutardialdehyde>>methylglyoxal≈acetaldehyde>>glyoxal>formaldehyde.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
90.
MICROBE-METAL-INTERACTIONS FOR THE BIOTECHNOLOGICAL TREATMENT OF METAL-CONTAINING SOLID WASTE 总被引:3,自引:0,他引:3
Helmut Brandl Mohammad A. Faramarzi 《中国颗粒学报》2006,4(2):93-97
In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat particulate solid wastes. Especially the microbiological solubilization of metals from solid minerals (termed bioleaching) to obtain metal values is a well-known technique in the mining industry. We focus here on non-mining minerai wastes to demonstrate the applicability of mining-based technologies for the treatment of metal-containing solid wastes. In the case study presented, microbial metal mobilization from particulate fly ash (originating from municipal solid waste incineration) by Acidithiobacilli resulted in cadmium, copper, and zinc mobilization of 〉80%, whereas lead, chromium, and nickel were mobilized by 2, 11 and 32%, respectively. In addition, the potential of HCN-forming bacteria (Chromobacterium violaceum, Pseudornonas fluorescens) was investigated to mobilize metals when grown in the presence of solid materials (e.g.,copper-containing ores, electronic scrap, spent automobile catalytic converters). C. violaceum was found capable of mobilizina nickel as tetracyanonickelate from fine-grained nickel powder. Gold was microbially solubJlized as dicyanoaurate from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit-board scraps. Water-soluble copper and platinum cyanide were also detected during the treatment of spent automobile catalytic converters. 相似文献