Treatment of stormwater sediments: Efficiency of an attrition scrubber – laboratory and pilot-scale studies

The purpose of this research is to present the efficiency of an attrition scrubber in the decontamination of stormwater sediments. Application of the attrition process serves to remove fine particles and contaminants from the surface of materials, i.e. sediment in the present case. This mechanical method has been evaluated both on the laboratory scale and at a pilot plant; the two treatments display different operating parameters. This article will introduce a ratio, defined as (R = mass% of pollutant/total mass%), to quantify the effect of attrition on the removal of pollutants (organic matter and trace elements). Screening and attrition have made it possible to concentrate pollutants into the fine fractions at ratio R, extending from 1.9 to 6.6. These results show that an attrition scrubber can remediate contaminated sediment and moreover that the remediation of stormwater sediment is indeed possible.     

The cellular fatty acid composition of bacteria in the family Vibrionaceae

It is shown that strains of Vibrio cholerae of serovar O1, biovar eltor, subtype Ogawa, museum strains V. cholerae of serovar O1 and NAG-vibrios (isolated from various sources: sea, river and sewage water, canal water and people) possess identical composition of cell fatty acids with prevailing hexadecenoic, hexadecanoic and octadecenoic acids. Being identical, fatty acid profiles of V. parahaemolyticus and V. alginolyticus, are close to that of V. cholerae differing from the latter mainly by the higher content of dodecanoic acid. Similarity of Aeromonas sp. and Vibrio strains in the fatty acid composition proves phylogenetic relation-ship of these bacteria. Fatty acid composition of Plesiomonas shigelloides cells characterized by the presence of methylenhexadecanoic acid as well as by similarity with Vibrio and Aeromonas by the content of most fatty acids confirms a supposition of R. R. Colwell on the intermediate status of genus Plesiomonas between the families Enterobacteriaceae and Vibrionaceae. Independent of the growth medium, the strains Vibrio. Aeromonas and Plesiomonas preserved a fatty-acid profile, inherent in them, with variations mainly in the content of fatty acids with the odd number of carbon atoms. Allowing for relative stability of fatty acid composition and its peculiarity in certain taxonomic groups of the studied bacteria, the above test may be used as additional objective criterion to identify the representatives of Vibrionaceae family.     

Functional Graded Materials Based on ZrO2 and Al2O3. Production Methods

The various methods for producing functional graded materials based on ZrO₂ and Al₂O₃ are reviewed: dry pressing followed by thermal treatment, diffusion welding, co-extrusion, chemical infiltration, electrophoretic deposition, centrifugal deposition, sedimentation, tape casting, slip casting, direct ceramic ink-jet printing.     

Effect of Al<Subscript>2</Subscript>O<Subscript>3</Subscript> on the properties of nanocrystalline ZrO<Subscript>2</Subscript> + 3 mol % Y<Subscript>2</Subscript>O<Subscript>3</Subscript> powder

We have studied the properties of nanocrystalline ZrO₂〈3 mol % Y₂O₃〉 and 90 wt % ZrO₂〈3 mol % Y₂O₃〉-10 wt % Al₂O₃ powders prepared via hydrothermal treatment of coprecipitated hydroxides at 210°C. The results demonstrate that Al₂O₃ doping raises the phase transition temperatures of the metastable low-temperature ZrO₂ polymorphs and that the structural transformations of the ZrO₂ and Al₂O₃ in the doped material inhibit each other.     

Modeling of hydrogen explosion on a pressure swing adsorption facility

Computational fluid dynamic simulations have been performed in order to study the consequences of a hydrogen release from a pressure swing adsorption installation operating at 30 barg. The simulations were performed using FLACS-Hydrogen software from GexCon. The impact of obstruction, partial confinement, leak orientation and wind on the explosive cloud formation (size and explosive mass) and on explosion consequences is investigated. Overpressures resulting from ignition are calculated as a function of the time to ignition.     

Flash heat processing of brown coals and hard-coal preparation products prior to their use for energy production

The principles of calculation of vortex chambers, in which flash heat processing of brown coal or a hard-coal beneficiation product with an ash content of 25–40% produced along can be run, are shown. Fast heat treatment of this type makes it possible to reduce the initial moisture content of brown coal from 35–40 to 2–12% and of coal preparation products, from 20–25 to 10–12%. In the basic parameters (fuel consumption, specific amount of metal, etc.), this method of reducing the moisture content is superior to traditional methods for drying coals and their preparation products (in drum, pipe, fluid-bed, or pneumatic dryers). After decreasing the moisture content of brown coals to a value of ≤3%, their bertinization, i.e., preparing a product with properties close to that of grade D coals, is also performed.     

First-principles investigations of interatomic interactions in Ni3Al alloyed by interstitial and substitutional impurities

First-principles calculations of the total energy of interstitial and substitutional solid solutions in intermetallic compound Ni₃Al were performed based on methods using Vienna ab-initio simulation package (VASP). The results of the calculations for interstitial solutions of carbon in Ni₃Al confirmed the priority role of chemical interactions over deformational ones for the nearest neighbors. We attempted to use first-principles methods of calculation of the deformation interaction and continuum approaching in the theory of solutions to calculate coefficients of the concentration changes of the lattice spacing. Comparison of the calculation results with experimental data of substitutional impurities in Ni₃Al has shown that the proposed method can aid in the study of the distribution of impurity atoms on the sublattices of the ordered phases, intermetallic compounds. We have proposed a method of calculating the partial molar volume of impurity in interstitial solid solutions.