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W pracy zaprezentowano dotychczasowe osiągnięcia w perwaporacyjnym odsiarczaniu benzyny krakingowej. Przedstawiono kryteria wstępnego doboru materiału warstwy aktywnej membran. Omówiono ponadto wpływ typowych węglowodorów oraz związków siarkoorganicznych obecnych w benzynie krakingowej na selektywność i właściwości transportowe membran jak również wpływ parametrów procesowych (temperatury nadawy, ciśnienia po stronie permeatu oraz szybkości przepływu nadawy) na efektywność procesu perwaporacyjnego odsiarczania. W pracy przedstawiono możliwość zastosowania komercyjnych membran kompozytowych z warstwą aktywną wykonaną z poli(dimetylosiloksanu) (PDMS) w procesie perwaporacyjnego odsiarczania benzyny pochodzącej z fluidalnego krakingu katalitycznego (FCC). Określono wpływ stężenia organicznych związków siarki na efektywność ich usuwania z organicznych mieszanin tiofen/n-heptan metodą perwaporacji próżniowej.

Environmental applications of carbon nanotubes (CNTs) have recently attracted worldwide attention due to their excellent adsorption capacities and promising physical, chemical and mechanical properties, as well as the preparation of novel membranes with attractive features for water purification. This paper critically reviews the recent progress on the preparation and applications of CNT based membranes in water and wastewater treatment. Various synthesis techniques for the preparation of CNT based membranes are discussed. The functionalization of CNTs, which involves chemical/physical modification of pristine CNTs with different types of functional groups, improves the capabilities of CNT for water and wastewater treatment and/or removal of waterborne contaminants. The CNT-based membrane applications are found to possess a variety of advantages, including improving water permeability, high selectivity and antifouling capability. However, their applications at full scale are still limited by their high cost. Finally, we highlight that CNT membranes with promising removal efficiencies for respective contaminants can be considered for commercialization and to achieve holistic performance for the purpose of water treatment and desalination. This paper may provide an insight for the development of CNT based membranes for water purification in the future. With their tremendous separation performance, low biofouling potential and ultra-high water flux, CNT membranes have the potential to be a leading technology in water treatment, especially desalination. [ABSTRACT FROM AUTHOR]

In recent decades, novel and promising graphene-based materials (i.e., carbon nanotubes, nanoporous graphene and graphene oxide) suitable to be used in preparation of high-capacity membranes for water desalination and water and wastewater treatment have been developed. After detail recognition of properties of nanoporous graphene and graphene oxide-based materials, the general conclusion on preparation of membranes made of only graphene or only graphene oxide as well as other composite materials involving these nanomaterials has been given. Novel composite membranes containing nanoporous graphene and, first of all, graphene oxide can be divided into two groups: (i) freestanding membranes made only of graphene or only of graphene oxide, and (ii) polymeric/ceramic membranes modified with the use of graphene-based nanomaterials. The modification of polymeric membranes can be achieved either by introduction of a nanomaterial onto a membrane surface or its addition to a membrane casting solution followed by membrane formation from a polymer and a nanomaterial mixture. Membranes based on nanomaterials enable to obtain significantly higher water/permeate fluxes than currently used thin film composite polyamide membranes. The future prospect of membranes based on nanoporous graphene and graphene oxide in regard to the final separation efficiency and commercial scaling up has been discussed. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Annual Set the Environment Protection / Rocznik Ochrona Środowiska is the property of Koszalin University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A series of vacuum pervaporation tests were carried out to investigate the performance of the commercial composite membrane with an active layer made of polydimethylsiloxane (PDMS). The effects of feed temperature, the sulfur content in the mixture, and feed composition on membrane performance were investigated. Toluene/thiophene andn-heptane/thiophene binary organic mixtures (thiophene concentration 0.8–1.6% by mass) simulating gasoline were separated at 30–50°C, at laboratory scale. Studies have shown that the concentration of thiophene in the mixture and the temperature of the feed have a significant impact on the yield and selectivity of the desulfurization process. Experimental results indicated that higher feed temperature yielded higher total and partial fluxes and a lower sulfur enrichment factor. The total and partial fluxes increased as the sulfur content in the feed increased. The sulfur enrichment factor decreased with the amount of thiophene added in the gasoline. The experiments also showed that commercial PDMS membrane was more selective to thiophene in the case ofn-haptane/thiophene mixture and it may be mainly due to higher affinity of toluene toward PDMS. The total fluxes forn-heptane/thiophene mixture and toluene/thiophene mixture were measured to be 7.4 and 9.4 kg/m2 h at 40°C, with the corresponding enrichment factor values of 1.7 and 1.4, respectively. [ABSTRACT FROM PUBLISHER]

Pervaporative separation properties of crosslinked chitosan and alginate membrane on ethanol-water mixture at room temperature was studied. The influence of crosslinking agents on the separation properties were discussed. Selected crosslinking agents were affected differently on used polymer matrices. The better separation properties were obtained for membranes crosslinked by phosphoric (V) acid. The highest pervaporation separation index (309.6 kg/m2·h) and separation factor (52.6) were obtained for phosphoric (V) acid crosslinked alginate membranes, however, the greatest total flux (12.4 kg/m2·h) obtained for phosphoric acid crosslinked chitosan membranes. [ABSTRACT FROM AUTHOR]