Tritium percolation through porous ceramic breeders - A random-lattice approach

Porous membrane of poly(tetrafluoroethylene) (PTFE) was formed on the surface of porous ceramic tubes by means of heat treatment of the PTFE particles deposit layer prepared by filtering PTFE microparticles emulsified in aqueous phase. By means of inert gas permeation, pore size was determined and compared with scanning electron micrograph observation. Also rejection measurement of aqueous dextran solutions of wide range of molecular weights showed consistent results regarding the pore size. Since the membrane prepared by this method is stable and has unique features derived from PTFE, it is expected that the membrane has interesting applications in the field of water treatment. Membrane separation of activated sludge by this composite membrane and original ceramics membrane showed that the PTFE membrane gives better detachability of the cake layer formed on the membrane. This might be due to the hydrophobic nature of the PTFE skin layer.

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Perspective Biomass Carrier for Anaerobic Processing Systems of Organic Waste AIC

Elektrotekhnologii i elektrooborudovanie v APK ◽

10.22314/2658-4859-2020-67-1-148-155 ◽

2020 ◽

Vol 67 (1) ◽

pp. 148-155

Author(s):

Anatoliy V. Fedotov ◽

Viktor S. Grigoriev ◽

Dmitriy A. Kovalev ◽

Andrey A. Kovalev

Keyword(s):

Wastewater Treatment ◽

Anaerobic Digestion ◽

Specific Surface ◽

Organic Waste ◽

Porous Ceramic ◽

Experimental Studies ◽

Ceramic Materials ◽

Porous Ceramics ◽

Developed Surface ◽

Highly Porous

To speed up the wastewater treatment under aerobic conditions and to optimize the processes of anaerobic wastewater treatment in digesters, immobilization technologies of microorganisms and enzymes on solid carriers are used. Ceramic carriers based on aluminosilicates and alumina are one of the promising inorganic biomass carriers. (Research purpose) To study the structure of porous ceramic biomass carriers for anaerobic processing of organic waste and evaluate the prospects for their use. (Materials and methods) The substrate for anaerobic digestion was a mixture of sediments of the primary and secondary sewage sumps of the Lyubertsy treatment facilities. K-65 cattle feed was used to ensure the constancy of the composition of organic substances in substrates as a cosubstrate. The authors used the method of low-temperature nitrogen adsorption of Bruner-Emmett-Teller to study the pore structure and specific surface of solid carriers on a specific surface analyzer Quntachrome Autosorb-1. (Results and discussion) The main characteristics (specific surface, volume of micro- and mesopores, predominant pore radius, water absorption and others) of chamotte foam lightweight and highly porous corundum ceramics were determined. It was revealed that ceramic materials with a developed surface and electrically conductive material provided an increase in biogas yield by 3.8-3.9 percent with an increase in methane content by an average of 5 percent. (Conclusions) The results of anaerobic digestion showed a positive effect of both a conductive carrier and highly porous ceramic materials on the process of anaerobic bioconversion of organic waste into biogas. It is advisable to expand experimental studies on the use of a conductive carrier with a developed surface based on highly porous ceramics.

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Thermal Evaluation of the Use of Porous Ceramic Plates on Ventilated Façades – Part I: Effect of Composition and Firing Temperature on Porosity and Bending Strength

International Journal of Applied Ceramic Technology ◽

10.1111/ijac.13827 ◽

2021 ◽

Author(s):

S. M. dos S. Pizzatto ◽

F. Pizzatto ◽

E. Angioletto ◽

S. Arcaro ◽

E. Junca ◽

...

Keyword(s):

Firing Temperature ◽

Bending Strength ◽

Porous Ceramic

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Modelling Sorption Thermodynamics and Mass Transport of n-Hexane in a Propylene-Ethylene Elastomer

Polymers ◽

10.3390/polym13071157 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1157

Author(s):

Daniele Tammaro ◽

Lorenzo Lombardi ◽

Giuseppe Scherillo ◽

Ernesto Di Maio ◽

Navanshu Ahuja ◽

...

Keyword(s):

Mass Transport ◽

Interaction Parameter ◽

Sorption Isotherms ◽

Binary Interaction ◽

Binary Interaction Parameter ◽

Theoretical Interpretation ◽

Sorption Behavior ◽

Solvent Mixtures ◽

Random Lattice ◽

Hexane Vapor

Optimization of post polymerization processes of polyolefin elastomers (POE) involving solvents is of considerable industrial interest. To this aim, experimental determination and theoretical interpretation of the thermodynamics and mass transport properties of POE-solvent mixtures is relevant. Sorption behavior of n-hexane vapor in a commercial propylene-ethylene elastomer (V8880 VistamaxxTM from ExxonMobil, Machelen, Belgium) is addressed here, determining experimentally the sorption isotherms at temperatures ranging from 115 to 140 °C and pressure values of n-hexane vapor up to 1 atm. Sorption isotherms have been interpreted using a Non Random Lattice Fluid (NRLF) Equation of State model retrieving, from data fitting, the value of the binary interaction parameter for the n-hexane/V8880 system. Both the cases of temperature-independent and of temperature-dependent binary interaction parameter have been considered. Sorption kinetics was also investigated at different pressures and has been interpreted using a Fick’s model determining values of the mutual diffusivity as a function of temperature and of n-hexane/V8880 mixture composition. From these values, n-hexane intra-diffusion coefficient has been calculated interpreting its dependence on mixture concentration and temperature by a semi-empiric model based on free volume arguments.

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