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This paper reviews the investigated applications of membrane reactors for in situ water removal during catalytic reactions in the food, pharmaceutical, cosmetics, and petrochemical sectors. The global target in the works reported herein was the design of a compact and more efficient catalytic reactor (process intensification). By applying in situ water removal, two objectives have been pursued: i) overcoming the thermodynamic limitations of the reaction and ii) avoiding catalyst poisoning. Different solution strategies proposed to overcome the difficulties in operating a membrane reactor in extreme acidic or temperature conditions are addressed covering various aspects ranging from membrane materials to reactor configuration design using pervaporation or vapor permeation techniques. As a general remark, membrane materials (polymeric and inorganic) still lack the required characteristics or reproducibility necessary for industrial application in the sectors under study. Further investigation is required to accomplish this task.

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The present work studies the functional behavior of novel poly(ε-caprolactone) (PCL) membranes functionalized with reduced graphene oxide (rGO) nanoplatelets under simulated in vitro culture conditions (phosphate buffer solution (PBS) at 37 °C) during 1 year, in order to elucidate their applicability as scaffolds for in vitro neural regeneration. The morphological, chemical, and DSC results demonstrated that high internal porosity of the membranes facilitated water permeation and procured an accelerated hydrolytic degradation throughout the bulk pathway. Therefore, similar molecular weight reduction, from 80 kDa to 33 kDa for the control PCL, and to 27 kDa for PCL/rGO membranes, at the end of the study, was observed. After 1 year of hydrolytic degradation, though monomers coming from the hydrolytic cleavage of PCL diffused towards the PBS medium, the pH was barely affected, and the rGO nanoplatelets mainly remained in the membranes which envisaged low cytotoxic effect. On the other hand, the presence of rGO nanomaterials accelerated the loss of mechanical stability of the membranes. However, it is envisioned that the gradual degradation of the PCL/rGO membranes could facilitate cells infiltration, interconnectivity, and tissue formation.

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Polymeric hollow fiber (HF) membranes are commercially available, i.e. microfiltration and ultrafiltration cartridges or reverse osmosis and gas separation modules, to be applied for separation purposes in industry, for instance to recover valuable raw materials or products, or for the treatment of end‐of‐pipe wastes to avoid environmental impacts, to regenerate or treat waters for reuse and for the separation of key components or clarification in food and beverage industries. They have also shown important benefits as hemodialyzers, hemodiafiltration or plasma purification devices in patients with liver or kidney damage. The good mass transport properties characterizing the polymeric HFs have opened new research areas of application in the biomedical field, such as the tissue engineering (TE) and the construction of bioartificial organs (BAO). In TE, the HFs act as scaffolds or supports and/or allow high permeance of nutrients and waste removal for cell proliferation and differentiation. In BAO, HFs are used for the fabrication of bio‐hybrid constructs that replace the damaged organs of the patient or can be used as in vitro models for therapeutic studies. This review presents the state‐of‐the‐art concerning preparation and application of HFs for TE and BAO and discusses the challenges and future perspectives of the HFs in both fields. © 2014 Society of Chemical Industry

The inherent resistance of perfluoroalkyl substances (PFASs) to biological degradation makes necessary to develop advanced technologies for the abatement of this group of hazardous substances. The present work investigated the photocatalytic decomposition of perfluorooctanoic acid (PFOA) using a composite catalyst based on TiO and reduced graphene oxide (95% TiO/5% rGO) that was synthesized using a facile hydrothermal method. The efficient photoactivity of the TiO-rGO (0.1gL) composite was confirmed for PFOA (0.24mmolL) degradation that reached 93±7% after 12h of UV-vis irradiation using a medium pressure mercury lamp, a great improvement compared to the TiO photocatalysis (24±11% PFOA removal) and direct photolysis (58±9%). These findings indicate that rGO provided the suited properties of TiO-rGO, possibly as a result of acting as electron acceptor and avoiding the high recombination electron/hole pairs. The release of fluoride and the formation of shorter-chain perfluorocarboxilyc acids, that were progressively eliminated in a good match with the analysed reduction of total organic carbon, is consistent with a step-by-step PFOA decomposition via photogenerated hydroxyl radicals. Finally, the apparent first order rate constants of the TiO-rGO UV-vis PFOA decompositions, and the intermediate perfluorcarboxylic acids were found to increase as the length of the carbon chain was shorter.

This paper reports the electrochemical treatment of poly-and perfluoroalkyl substances (PFASs) in the effluent from an industrial wastewater treatment plant (WWTP). While most of the previous research focused on the electrochemical degradation of perfluorooctanoic acid and perfluorooctane sulfonate in model solutions, this work studies the simultaneous removal of 8 PFASs at environmentally relevant concentrations in real industrial emissions, which also contained organic matter and inorganic anions. The overall PFASs content in the WWTP effluent was 1652 µg/L, which emphasized the need to develop innovative technologies for the management of PFASs emissions. 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB) and 6:2 fluorotelomer sulfonate (6:2 FTSA) were the major contributors (92% w/w) to the overall PFASs content, that also contained significant amounts of short-chain perfluorocarboxylic acids (PFCAs). Using a boron doped diamond (BDD) anode of 0.0070 m 2 , the effluent (2 L) was treated by applying a current density of 50 mA/cm 2 for 10 hours, that resulted in 99.7% PFASs removal. The operation at lower current densities (5 and 10 mA/cm 2 ) evidenced the initial degradation of 6:2 fluorotelomers into perfluoroheptanoic and perfluorohexanoic acids, that were later degraded into shorter chain PFCAs. The high TOC removal, >90%, and the fluoride release revealed that PFASs mineralization was effective. These results highlight the potential of the electrochemical technology for the treatment of PFASs contained in industrial wastewaters, which nowadays stands as the main source of this group of persistent pollutants into the environment.