scholarly journals Critical Issues and Guidelines to Improve the Performance of Photocatalytic Polymeric Membranes

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 570 ◽  
Author(s):  
Marta Romay ◽  
Nazely Diban ◽  
Maria J. Rivero ◽  
Ane Urtiaga ◽  
Inmaculada Ortiz

Photocatalytic membrane reactors (PMR), with immobilized photocatalysts, play an important role in process intensification strategies; this approach offers a simple solution to the typical catalyst recovery problem of photocatalytic processes and, by simultaneous filtration and photocatalysis of the aqueous streams, facilitates clean water production in a single unit. The synthesis of polymer photocatalytic membranes has been widely explored, while studies focused on ceramic photocatalytic membranes represent a minority. However, previous reports have identified that the successful synthesis of polymeric photocatalytic membranes still faces certain challenges that demand further research, e.g., (i) reduced photocatalytic activity, (ii) photocatalyst stability, and (iii) membrane aging, to achieve technological competitiveness with respect to suspended photocatalytic systems. The novelty of this review is to go a step further to preceding literature by first, critically analyzing the factors behind these major limitations and second, establishing useful guidelines. This information will help researchers in the field in the selection of the membrane materials and synthesis methodology for a better performance of polymeric photocatalytic membranes with targeted functionality; special attention is focused on factors affecting membrane aging and photocatalyst stability.

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 162 ◽  
Author(s):  
Pietro Argurio ◽  
Enrica Fontananova ◽  
Raffaele Molinari ◽  
Enrico Drioli

The present work gives a critical overview of the recent progresses and new perspectives in the field of photocatalytic membranes (PMs) in photocatalytic membrane reactors (PMRs), thus highlighting the main advantages and the still existing limitations for large scale applications in the perspective of a sustainable growth. The classification of the PMRs is mainly based on the location of the photocatalyst with respect to the membranes and distinguished in: (i) PMRs with photocatalyst solubilized or suspended in solution and (ii) PMRs with photocatalyst immobilized in/on a membrane (i.e., a PM). The main factors affecting the two types of PMRs are deeply discussed. A multidisciplinary approach for the progress of research in PMs and PMRs is presented starting from selected case studies. A special attention is dedicated to PMRs employing dispersed TiO2 confined in the reactor by a membrane for wastewater treatment. Moreover, the design and development of efficient photocatalytic membranes by the heterogenization of polyoxometalates in/on polymeric membranes is discussed for applications in environmental friendly advanced oxidation processes and fine chemical synthesis.


2018 ◽  
Vol 13 (1) ◽  
pp. 45-52
Author(s):  
Aynura Manaf kizi Ismayilova ◽  

2012 ◽  
Vol 20 (7) ◽  
pp. 695-700 ◽  
Author(s):  
Toru Sugihara ◽  
Hideo Yasunaga ◽  
Hiromasa Horiguchi ◽  
Tetsuya Fujimura ◽  
Hiroaki Nishimatsu ◽  
...  

Author(s):  
I. G. Wenten ◽  
K. Khoiruddin ◽  
R. R. Mukti ◽  
W. Rahmah ◽  
Z. Wang ◽  
...  

Coupling chemical reaction with membrane separation or known as membrane reactor (MR) has been demonstrated by numerous studies and showed that this strategy has successfully addressed the goal of process intensification.


2011 ◽  
Vol 3 (3) ◽  
pp. 414-416 ◽  
Author(s):  
Nathan H Boyd ◽  
Raul M Cruz

Abstract Background The objective of this study was to determine the extent of interest in international electives among prospective otolaryngology residents and to determine whether the availability of international electives affected students' interest in ranking a particular residency program. Methods A 3-part survey was given to all medical students enrolled in the 2008 otolaryngology match via the Electronic Residency Application Service. Part 1 elicited demographic information. Part 2 explored general interest in international rotations. Part 3 involved ranking several factors affecting students' choice of residency programs. This survey was developed at our institution, with no formal validation. Participation was anonymous and voluntary. Results A total of 307 students entered the otolaryngology match, and 55 surveys (18%) were completed. Twenty-five of 55 students (55%) had completed an international elective during or prior to medical school, and 51 of 55 respondents (93%) had a “strong” or “very strong” desire to participate in an international elective during residency; 48 of 55 students (87%) had a “strong” or “very strong” desire to participate in international surgical missions after residency. Future practice goals had no correlation with interest in international rotations, either during or after residency training. Respondents ranked 8 factors that had an impact on residency program selection in the following order of importance: operative experience, location, lifestyle, research opportunities, didactics, international electives, prestige of program, and salary. Conclusion Interest in international medicine among prospective otolaryngologists was high in this subset of respondents but did not appear to affect residency program selection.


2005 ◽  
Vol 83 (9) ◽  
pp. 1240-1245 ◽  
Author(s):  
Iain J Stenhouse ◽  
H Grant Gilchrist ◽  
William A Montevecchi

The selection of breeding habitat is of prime importance for individual fitness. Among birds, natural selection should favour the ability to recognize and select habitat suitable for nesting and rearing chicks. This study compares the characteristics of Sabine's Gull, Xema sabini (Sabine, 1819), nest sites with random points across a coastal tundra environment on Southampton Island, Nunavut, Canada. The availability of terrestrial invertebrate prey was also examined among habitats. Sabine's Gull nests were nonrandomly distributed in relation to vegetation, substrate, and proximity to water. Gulls nested within approximately 1 km of the coastline and selected sites with the greatest proportions of moss and standing water (i.e., they nested close to the edge of small freshwater ponds near shore). However, there were no detectable differences in characteristics between successful and unsuccessful nests within preferred habitat. The dynamics of terrestrial invertebrate prey communities varied between years, but the volume of invertebrates in Sabine's Gull nesting habitat was intermediate between the most productive habitats and the least productive habitats in both years. However, nest-site selection in Sabine's Gulls may also be influenced by the availability of aquatic invertebrates (not examined in this study) and their proximity to the marine coastline, where chicks are taken to be reared.


2014 ◽  
Vol 5 (1) ◽  
pp. 97-124 ◽  
Author(s):  
Mehdi Behboudi ◽  
Hossein Vazifehdoust ◽  
Kobra Najafi ◽  
Mina Najafi

Purpose – The purpose of this study is to verify the factors affecting the use of emotional and rational appeals in online advertising among Muslim customers in Iran. Design/methodology/approach – By reviewing the literature of advertising appeals and developing a comprehensive theoretical model, the effect of rational and emotional appeals on online advertising was examined. Expert questionnaire was administered to verify the validity of collected features. The Student's t-test was utilized to analyze the data collected from 271 participants. Findings – Five latent variables, namely user type, product involvement, e-lifestyle, advertising strategies, and internet motives were examined to explain factors affecting online advertising appeals among Muslim customers in Iran. It was found that “advertising strategies” and “user type” are the most effective factors influencing Muslims customers in developing an online advertising campaign. Research limitations/implications – The sample of this study was Iranian experts and it is necessary to conduct a survey with a larger sample size. Originality/value – This study provides insights into factors affecting the selection of emotional and rational appeals in Muslims countries. Moreover, it reports the primary columns of online advertising appeals.


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