Mesoscale Simulations of Particle Rejection by Microfiltration Membranes with Straight Cylindrical Pore during Pressure-Driven Dead-End Filtration

2016 ◽  
Vol 49 (5) ◽  
pp. 452-459 ◽  
Author(s):  
Kazuki Akamatsu ◽  
Shosuke Kanasugi ◽  
Tsutomu Ando ◽  
Osamu Koike ◽  
Masahiro Fujita ◽  
...  
2010 ◽  
Vol 43 (10) ◽  
pp. 815-828 ◽  
Author(s):  
Tsutomu Ando ◽  
Kazuki Akamatsu ◽  
Masahiro Fujita ◽  
Shin-ichi Nakao

2019 ◽  
Vol 13 (1) ◽  
pp. 6 ◽  
Author(s):  
Iqbal Shalahuddin ◽  
Yusuf Wibisono

A B S T R A C TMicrofiltration is a low pressure driven membrane process of about 1 bar trans-membrane pressure which is used frequently for separating dissolved particles within 0.1 to 10 μm size. Microfiltration membranes are utilized in water and wastewater treatment processes either during pretreatment, treatment, or post-treatment steps. Moreover in bioprocessing, microfiltration is used in upstream process for substrate sterilization or in downstream process for microbial suspension separation. Fouling is one major concern of membrane filtration processes, including microfiltration. In this article, the fouling mechanism on microfiltration membrane is explained based on the blocking model refer to cake filtration due to the complexity of fouling phenomena. Fouling mechanism on dead-end and cross-flow modes microfiltration are explained, and basically distinguished into four different mechanisms, i.e. complete blocking, standard blocking, intermediate blocking and cake filtration. The proposed models are based on constant pressure operation on the uniform membrane pores, both for dead-end and cross-flow modes. Cross-flow mode, however, is restricted on the beginning of filtration until critical flux condition is reached.Keywords: bioprocess; blocking model; cake filtration; fouling; microfiltration; wastewater A B S T R A KMembran mikrofiltrasi merupakan salah satu teknologi membran yang menggunakan tekanan rendah sekitar 1 bar sebagai gaya pendorong dan digunakan untuk proses pemisahan partikel terlarut yang berukuran antara 0,1 hingga 10 μm. Membran mikrofiltrasi banyak digunakan baik dalam proses pra-pengolahan, pengolahan, maupun pasca-pengolahan air dan air limbah. Pada bioproses, mikrofitrasi juga digunakan pada proses hulu untuk sterilisasi substrat atau pada proses hilir untuk pemisahan suspensi mikrob. Masalah yang paling utama dalam proses filtrasi membran adalah fouling. Dalam artikel ini, mekanisme terjadinya fouling pada membran mikrofiltrasi dijelaskan dengan menggunakan model pemblokiran yang mengacu pada filtrasi deposit partikel (cake) untuk menguraikan kerumitan fenomena fouling dalam mikrofiltrasi. Pada tulisan ini dijelaskan lebih rinci mengenai mekanisme fouling baik pada mikrofiltrasi searah (dead-end) maupun aliran silang (cross-flow). Mekanisme fouling pada proses mikrofiltrasi bisa dimodelkan dengan empat model yaitu pemblokiran pori, penyempitan pori, pemblokiran pori bersamaan dengan endapan permukaan dan formasi endapan permukaan. Mekanisme tersebut berlaku pada kondisi operasional bertekanan tetap dan ukuran pori yang seragam, baik pada aliran searah ataupun silang. Hanya saja, model mekanisme pada aliran silang hanya berlaku pada kondisi awal filtrasi hingga tercapai kondisi fluks kritis.Kata kunci: air limbah; bioproses; filtrasi cake; fouling; mikrofiltrasi; model pemblokiran


2003 ◽  
Vol 3 (5-6) ◽  
pp. 93-99 ◽  
Author(s):  
Y. Matsui ◽  
T. Matsushita ◽  
T. Inoue ◽  
M. Yamamoto ◽  
Y. Hayashi ◽  
...  

The performance and mechanism of virus removal by microfiltration with coagulation pretreatment were investigated. We confirmed the unexpectedly high performance of virus removal for two types of ceramic membrane system: a positive pressure-driven dead-end filtration with inside-out configuration and a vacuum pressure-driven dead-end immersed filtration with outside-in configuration. Virus removals by both systems were more than 7 logs, although the size of the tested Qβ virus (23 nm) was much smaller than the membrane nominal pore size of 100 nm. The virus inactivation by the addition of the coagulant (PACl) and the virus adsorption onto the floc retained on the membrane surface mainly contributed the virus removal. No virus accumulation in the retentate was observed, possibly due to the virus inactivation by the coagulant.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 489-496 ◽  
Author(s):  
Gemunu Herath ◽  
Kazuo Yamamoto ◽  
Taro Urase

Microorganisms such as Qβ, MS2, T4 virus and several bacteria strains in Pseudomonas, Alcaligenes and E-coli groups were filtered with different pore size nuclepore and anopore flat sheet membranes in dead end mode. The obtained rejection results were analyzed with existing pore models in which the rejection is related to the ratio of solute size to pore size. The existing pore models (transport equations) were adjusted to accommodate the microfiltration range particles. The adjusted pore models showed good agreement with the obtained experimental rejection results for virus while the bacteria rejection results showed a deviation. This deviation is partially explained with the wide size distribution of bacteria. The equivalent spherical diameter can be used to represent the virus size while the oval diameter of the cells may be the best possible dimension for bacteria size in membrane filtration. This determination showed the possibility of bacteria cells approaching the membrane pores in their longitudinal direction.


2012 ◽  
Vol 51 (1-3) ◽  
pp. 416-422 ◽  
Author(s):  
Julie Guilbaud ◽  
Anthony Massé ◽  
François-Charles Wolff ◽  
Pascal Jaouen
Keyword(s):  
Dead End ◽  

2012 ◽  
Vol 2 (1) ◽  
pp. 49-80
Author(s):  
Evrea Ness-Bergstein

In Lewis’ transposition of Milton’s Paradise to a distant world where Adam and Eve do not succumb to Satan, the structure of Eden is radically different from the enclosed garden familiar to most readers. In the novel Perelandra (1944), C.S. Lewis represents the Garden of Eden as an open and ‘shifting’ place. The new Garden of Eden, with Adam and Eve unfallen, is a place of indeterminate future, excitement, growth, and change, very unlike the static, safe, enclosed Garden—the hortus conclusus of traditional iconography—from which humanity is not just expelled but also, in some sense, escapes. The innovation is not in the theological underpinnings that Lewis claims to share with Milton but in the literary devices that make evil in Perelandra seem boring, dead-end, and repetitive, while goodness is the clear source of change and excitement.


Romanticism ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 22-35
Author(s):  
Nicola Healey

The literary career and troubled life of Derwent Moultrie Coleridge (1828–80), Derwent Coleridge's eldest son (S. T. Coleridge's first grandson) has been critically overlooked. After a period of alcohol-related, reckless behaviour at Cambridge University, he was exiled to Australia in November 1850, lest he continue to dishonour his father and the Coleridge name. Despite struggling considerably, he quickly became part of an Australian literary circle and he often contributed poems to Sydney newspapers. This essay analyses the most biographical of his poems that was published in the Australian press, ‘The Loafer's Christmas’ (1871) – a hitherto unknown poem – looking, in particular, at the dialogues in which the poem engages with his family, especially S. T. Coleridge's ‘The Rime of the Ancient Mariner’. I also contextualise ‘The Loafer's Christmas’ within nineteenth-century Australian culture. Looking at issues of exile, idleness, addiction, family, home(lessness), and religious redemption, this essay explores the ways in which Derwent Moultrie's exile proved to be both a literary liberation and a dead end, trapping him between times and spaces, real and imaginary. In so doing, I show how the lost life and writings of Derwent Moultrie Coleridge can offer us new perspectives on the Coleridge legacy.


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