Hollow fiber dead-end ultrafiltration: Influence of ionic environment on filtration of alginates

2008 ◽  
Vol 308 (1-2) ◽  
pp. 218-229 ◽  
Author(s):  
W.J.C. van de Ven ◽  
K. van’t Sant ◽  
I.G.M. Pünt ◽  
A. Zwijnenburg ◽  
A.J.B. Kemperman ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Ionic Environment ◽  
Dead End

Drinking water production by coagulation-microfiltration and adsorption-ultrafiltration

1998 ◽  
Vol 37 (10) ◽  
pp. 135-146 ◽  
Author(s):  
Akira Yuasa
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Hollow Fiber ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Cellulose Acetate Membrane ◽  
Water Recovery ◽  
Dead End ◽  
Iron Manganese ◽  
Gac Adsorption

Microfiltration (MF) and ultrafiltration (UF) pilot plants were operated to produce drinking water from surface water from 1992 to 1996. Microfiltration was combined with pre-coagulation by polyaluminium chloride and was operated in a dead-end mode using hollow fiber polypropylene and monolith type ceramic membranes. Ultrafiltration pilot was operated in both cross-flow and dead-end modes using hollow fiber cellulose acetate membrane and was combined occasionally with powdered activated carbon (PAC) and granular activated carbon (GAC) adsorption. Turbidity in the raw water varied in the range between 1 and 100 mg/L (as standard Kaolin) and was removed almost completely in all MF and UF pilot plants to less than 0.1 mg/L. MF and UF removed metals such as iron, manganese and aluminium well. The background organics in the river water measured as KMnO4 demand varied in the range between 3 and 16 mg/L. KMnO4 demand decreased to less than 2 mg/L and to less than 3 mg/L on the average by the coagulation-MF process and the sole UF process, respectively. Combination of PAC or GAC adsorption with UF resulted in an increased removal of the background organics and the trihalomethanes formation potential as well as the micropollutants such as pesticides. Filtration flux was controlled in the range between 1.5 and 2.5 m/day with the trans-membrane pressure less than 100 kPa in most cases for MF and UF. The average water recovery varied from 99 to 85%.

A New Short–Cut Design Method for Ultrafiltration and Hyperfiltration Cross–Flow Hollow Fiber Membrane Modules

2012 ◽  
Author(s):  
Wan Ramli Wan Daud
Keyword(s):  
Hollow Fiber ◽  
Driving Force ◽  
Hollow Fiber Membrane ◽  
Cross Flow ◽  
Extinction Curve ◽  
Membrane Area ◽  
Transfer Unit ◽  
Dead End ◽  
The Dead ◽  
The Difference

Although ultrafiltration and hyperfiltration have replaced many liquid phase separation equipment, both are still considered as “non–unit operation” processes because the sizing of both equipments could not be calculated using either the equilibrium stage, or the rate–based methods. Previous design methods using the dead–end and complete–mixing models are unsatisfactory because the dead–end model tends to underestimate the membrane area, due to the use of the feed concentration in the driving force, while the complete–mixing model tends to overestimate the membrane area, due to the use of a more concentrated rejection concentration in the driving force. In this paper, cross–flow models for both ultrafiltration and hyperfiltration are developed by considering mass balance at a differential element of the cross–flow module, and then integrating the expression over the whole module to get the module length. Since the modeling is rated–based, the length of both modules could be expressed as the product of the height of a transfer unit (HTU), and the number of transfer unit (NTU). The solution of the integral representing the NTU of ultrafiltration is found to be the difference between two exponential integrals (Ei(x)) while that representing the NTU of hyperfiltration is found to be the difference between two hypergeometric functions. The poles of both solutions represent the flux extinction curves of ultrafiltration and hyperfiltration. The NTU for ultrafiltration is found to depend on three parameters: the rejection R, the recovery S, and the dimensionless gel concentration Cg. For any given Cg and R, the recovery, S, is limited by the corresponding flux extinction curve. The NTU for hyperfiltration is found to depend on four parameters: the rejection R, the recovery S, the polarization β, and the dimensionless applied pressure difference ψ. For any given ψ and R, the recovery, S, is limited by the corresponding flux extinction curve. The NTU for both ultrafiltration and hyperfiltration is found to be generally small and less than unity but increases rapidly to infinity near the poles due to flux extinction. Polarization is found to increase the NTU and hence the length and membrane area of the hollow fiber module for hyperfiltration. Key words: Ultrafiltration; hyperfiltration; reverse osmosis; hollow fiber module design; crossflow model; number of transfer unit; height of a transfer unit

Improving the performance of dead-end ultrafiltration systems: comparing air and water flushing

2001 ◽  
Vol 1 (5-6) ◽  
pp. 97-106
Author(s):  
M. Kennedy ◽  
S. Siriphannon ◽  
S. van Hoof ◽  
J. Schippers
Keyword(s):  
Hollow Fiber ◽  
Shear Force ◽  
Feed Water ◽  
Cake Filtration ◽  
Maximum Flux ◽  
Filtration Cycle ◽  
System A ◽  
Dead End ◽  
Cake Layer ◽  
Net Flux

A cleaning protocol that effectively removes fouling from hollow fiber UF systems without excessive use of chemicals, product water or (long) down time is needed. Cross flushing with UF feed water has been reported to increase the net flux of hollow fiber systems by reducing the frequency of backwashing, the consumption of permeate and the system down time. In this study, the flux restoration achieved in a vertical and horizontal UF system employing an intermittent water and water/air cross flush were compared. The flux restoration in the vertical UF system was not improved by the addition of air to the water flush and a maximum flux restoration of 82% was achieved, irrespective of the presence of air. Similarly, in a horizontal ultrafiltration system, a maximum flux restoration of 82% was also achieved with a water flush (v = 1.63 m/s). However, the addition of air to the water flush decreased the flux restoration to 40% at the highest water/air ratio (33% air). Low flux restoration in the horizontal system was attributed to residual air in the module after cross flushing. Flushing with water alone (v = 1.63 m/s) yielded a wall shear stress of 16 Pa compared with 130 Pa and 279 Pa in the liquid film surrounding the air slugs in the horizontal and vertical UF system, respectively, with a water/air ratio of 2:1. Despite the high shear force on the cake layer accumulated when air was added to the system, the maximum flux restoration was 82% both with and without air. This was attributed to the fact that it was the filtration mechanism and not the shear force on the cake layer that limited flux restoration during cross flushing. To improve the flux restoration that can be achieved by the cross flushing process, the filtration mechanism must be manipulated to minimize blocking filtration and induce cake filtration from the beginning of each filtration cycle.

Fouling Behavior of Microstructured Hollow Fiber Membranes in Dead-End Filtrations: Critical Flux Determination and NMR Imaging of Particle Deposition

Langmuir ◽  
2011 ◽  
Vol 27 (5) ◽  
pp. 1643-1652 ◽  
Author(s):  
P. Zeynep Çulfaz ◽  
Steffen Buetehorn ◽  
Lavinia Utiu ◽  
Markus Kueppers ◽  
Bernhard Bluemich ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Particle Deposition ◽  
Nmr Imaging ◽  
Hollow Fiber Membranes ◽  
Critical Flux ◽  
Dead End ◽  
Fiber Membranes ◽  
Flux Determination

scholarly journals Membran Separasi Serat Berongga untuk Hemodialisis

2019 ◽  
Vol 7 (1) ◽  
pp. 27-36
Author(s):  
Krisna Lumban Raja
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Salt Water ◽  
Cross Flow ◽  
Polymer Chains ◽  
Current Status ◽  
Separation Membranes ◽  
Fiber Separation ◽  
Dead End ◽  
Wide Range

Polimer mempunyai aplikasi luas. Campuran heterogennya membentuk struktur fasa terpisah menjadi membran untuk membuat perangkat medis. Fungsi membran melakukan penghalangan selektif dengan aspek keragaman : tebal, struktur, diameter pori, muatan listrik, perpindahan partikel. Grup. Membran separasi adalah membran sintetis untuk pemisahan. Membuat membran separasi polimerik dibutuhkan kriteria polimer berdaya rekat rendah, berdaya tahan pembersihan tinggi, berkarakteristik rantai polimer saling cocok, harga murah, serta mudah diperoleh. Sifat kimia permukaan membran memberi konsekuensi pembasahan atau pencemaran yang mempengaruhi daya tahan membran. Konfigurasi membran separasi adalah silang aliran dan dead-end.Hukum Darcy merumuskan pemodelan yang pokok pada membran separasi dead end. Serat membran morfologinya keropos dan gaya pendorongnya perbedaan konsentrasi. Aliran nya silang dan modulnya menampung hingga 10.000 serat berdiameter 200 μm sampai 2500 μm. Pada dialisis, aliran darah dan dialisat berlawanan, agar pengeluaran zat-zat beracun maksimal. Aplikasi membran serat berongga untuk hemodialisis karena gagal ginjal kronis. Hakekat dialisis adalah memindahkan zat-zat racun dari metabolisme dan memperbaiki keseimbangan garam, air dan asam dalam darah. Status iptek terkini membran hemodialisis adalah pada ginjal buatan dari bahan hidup selain peralatan hemodialisis yang dapat berpindah-pindah, dibawa, dikenakan di badan, dan ditanam dalam tubuh.Kata kunci : Membran, Sintetis, Separasi, Hemodialisis, Serat berongga.AbstractPolymers have a wide range of uses. Their heterogenous blends form separated phase structures to become membranes for making medical devices. Membranes serve as selective barriers with various classifications such as thickness, structure, pore diameter, electric charged, particle transport, and in groups. A separation membrane is synthetically created for separation purpose. To make polymeric separation membranes require polymers that are low binding affinity, withstand the harsh cleaning conditions, suitable with properties of polymer chains, reasonable pricing, and easily obtainable. Two flow configurations of separation membranes are cross flow and dead-end filtrations. Darcy’s law formulates the main modeling equation for the dead end filtration. Hollow fiber separation membranes have porous morphology and driving force of concentration gradients. They have cross flows and their modules can contain up to 10.000 fibers ranging from 200 to 2500 μm in diameter. In dialysis, blood travels in the opposite direction with the dialysate to maximize the excretion of poisonous substances. A hollow fiber membrane application is for hemodialysis of chronic renal failure that causes physiological derangements. Actually dialysis is to remove toxic end-products of nitrogen metabolism and improve the balance of the salt, water, and acid-base derangements in blood. The current status of hemodialysis are the bio-artificial kidneys along with the development of mobile, portable, wearable and implantable hemodialysis devices.Keywords : Membrane, Synthetic, Separation, Hemodialysis, Hollow-fiber.

scholarly journals Pengolahan Air Tanah di Kawasan Politeknik Negeri Bandung menjadi Air Minum dengan Metoda Ultrafiltrasi

2018 ◽  
Vol 2 (2) ◽  
pp. 55
Author(s):  
Emma Hermawati Muhari ◽  
Ayu Ratna Permanasari ◽  
Fitria Yulistiani
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Ground Water ◽  
Hollow Fiber ◽  
Vinylidene Fluoride ◽  
Hollow Fiber Membrane ◽  
Drinking Water Treatment ◽  
Dead End ◽  
Long Time ◽  
Total Dissolved Solid

Di Indonesia, khususnya di sekitar Politeknik Negeri Bandung, sebagian besar sumber air berasal dari air tanah. Air tanah di lingkungan Politeknik Negeri Bandung memiliki pH asam (< 6), coliform > 2.400, dan colitinja positif. Proses pemanasan air kurang efektif untuk mengolah air tanah karena memerlukan waktu yang relatif lama, energi besar, dan tidak dapat meningkatkan pH air agar memenuhi standar air minum sebagaimana tercantum dalam Permenkes Nomor 492/MENKES/PER/IV/2010. Untuk mengolah air tanah di lingkungan Politeknik Negeri Bandung, telah dibuat alat pengolahan air minum portabel dengan menggunakan konsep aliran dead-end filtration. Membran yang dipakai merupakan membran hollow-fiber, berjenis membran ultrafiltrasi berbahan dasar PVDF (Poly Vinylidene Flouride), ukuran pori 0,1μm, panjang membran 15cm, jumlah membran sebanyak 148 buah, dan dapat dioperasikan pada daya isap normal manusia.  Permeat yang dihasilkan sesuai dengan standar PERMENKES No. 492/MENKES/PER/IV/2010 dari parameter fisika, kimia, dan biologi. Lifetime membran diamati melalui jumlah permeat yang dihasilkan dari awal pemakaian membran hingga membran tersebut rusak. Lifetime pada alat pengolah air minum portabel ini adalah 38,879 L. Pengolahan air tanah menggunakan alat ini  dapat menaikkan pH sebesar 12,78%, menurunkan konduktivitas sebesar 39,31%, dan menurunkan Total Dissolved Solid (TDS) 13,72%. Dari segi ekonomi, penggunaan alat ini dapat menghemat biaya 50% dibandingkan dengan pembelian air minum kemasan 600 ml.In Indonesia, especially around the Bandung State Polytechnic, most of the water sources come from ground water. Ground water in the Bandung State Polytechnic environment has acidic pH (<6), coliform> 2,400, and positive colitis. The process of water heating is less effective for treating ground water because it requires a relatively long time, large energy, and can not increase the pH of the water to meet drinking water standards as stated in Permenkes No. 492 / MENKES / PER / IV / 2010. To treat ground water in the Bandung State Polytechnic, portable drinking water treatment equipment has been made using the concept of dead-end flow filtration. The membrane used is a hollow-fiber membrane, a type of ultrafiltration membrane made from PVDF (Poly Vinylidene Fluoride), pore size of 0.1μm, membrane length of 15cm, membrane number of 148 pieces, and can be operated on normal human suction. The permeate produced is in accordance with PERMENKES No. 492 / MENKES / PER / IV / 2010 from physical, chemical and biological parameters. Lifetime membranes are observed through the amount of permeate produced from the beginning of the use of the membrane until the membrane is damaged. Lifetime of this portable drinking water treatment device is 38,879 L. Ground water treatment using this tool can increase pH by 12.78%, decrease conductivity by 39.31%, and reduce Total Dissolved Solid (TDS) 13.72%. From an economic standpoint, the use of this tool can save 50% costs compared to the purchase of 600 ml of bottled water.

Dead-end ultrafiltration in hollow fiber modules: Module design and process simulation

1998 ◽  
Vol 145 (2) ◽  
pp. 159-172 ◽  
Author(s):  
Christophe Serra ◽  
Michael J Clifton ◽  
Philippe Moulin ◽  
Jean-Christophe Rouch ◽  
Philippe Aptel
Keyword(s):  
Hollow Fiber ◽  
Process Simulation ◽  
Module Design ◽  
Dead End

scholarly journals Dead-End Hollow-Fiber Ultrafiltration for Recovery of Diverse Microbes from Water

2009 ◽  
Vol 75 (16) ◽  
pp. 5284-5289 ◽  
Author(s):  
Carmela M. Smith ◽  
Vincent R. Hill
Keyword(s):  
Cryptosporidium Parvum ◽  
Hollow Fiber ◽  
Water Samples ◽  
Tap Water ◽  
Surfactant Solution ◽  
Flow Rates ◽  
Average Recovery ◽  
Dead End ◽  
Alternative Approach ◽  
Filter Clogging

ABSTRACT Dead-end ultrafiltration (DEUF) is an alternative approach to tangential-flow hollow-fiber ultrafiltration that can be readily employed under field conditions to recover microbes from water. The hydraulics of DEUF and microbe recovery for a new DEUF method were investigated using 100-liter tap water samples. Pressure, flow rate, and temperature were investigated using four hollow-fiber ultrafilter types. Based on hydraulic performance, the Asahi Kasei REXEED 25S ultrafilter was selected for microbe recovery experiments. Microbe recovery experiments were performed using MS2 bacteriophage, Enterococcus faecalis, Clostridium perfringens spores, and Cryptosporidium parvum oocysts. Microbes were recovered from ultrafilters by backflushing using a surfactant solution. Average flow rates were 2.1 liters/min for 100-liter water samples having turbidities of 0.28 to 4.3 nephelometric turbidity units (NTU), and no evidence of appreciable filter clogging was observed. The DEUF average recovery efficiencies for each study analyte in tap water were as follows: for E. faecalis, 93% ± 16%; for MS2, 57% ± 7.7%; for C. perfringens spores, 94% ± 22%; and for C. parvum, 87% ± 18%. Average microbe recoveries for tap water amended with surface water (average turbidity = 4.3 NTU) were as follows: for E. faecalis, 78% ± 12%; for MS2, 73% ± 13%; for C. perfringens, 57% ± 21%; and for C. parvum, 83% ± 21%. These data demonstrate that DEUF is an effective method for recovering diverse microbes from water and should be a useful tool for field-based environmental investigations.

scholarly journals Purification of lake water using a PES hollow fiber membrane

2019 ◽  
Vol 20 (2) ◽  
pp. 529-537
Author(s):  
K. M. W. Carolyn ◽  
M. U. M. Junaidi ◽  
N. A. Hashim ◽  
M. A. Hussain ◽  
F. Mohamed Zuki ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Purification ◽  
Hollow Fiber ◽  
Water Samples ◽  
Hollow Fiber Membrane ◽  
Class Ii ◽  
Class I ◽  
Raw Water ◽  
Fiber Membrane ◽  
Dead End

Abstract Water scarcity combined with increasing populations will create a massive problem of obtaining clean water sources in the future. In this research, a newly developed polyethersulfone (PES) hollow fiber membrane from Universiti Sains Malaysia (USM) is used in water purification experiments using raw water samples obtained from Varsity Lake of the University of Malaya (UM) and a lake in Taman Jaya. The raw water samples undergo water quality characteristics tests to determine their class of water quality based on national water quality standards. Both raw water samples have been characterized and belong to class II of water quality. Subsequently, both raw water samples are used in water purification experiments with two types of filtration configuration, cross-flow and dead-end. Results show that water purification using the PES hollow fiber membrane can obtain water quality of class I for both samples. However, the presence of Escherichia coli can still be detected in both purified water samples. From the results obtained, the fabricated PES membrane is able to filter raw water samples of WQI Class II to WQI Class I quality and adhere to drinking water standards, and the dead-end filtration configuration provides the best filtration performance.

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