scholarly journals New Generation Ceramic Membranes have the Potential of Removing Endotoxins from Dialysis Water and Dialysate

2005 ◽  
Vol 28 (7) ◽  
pp. 694-700 ◽  
Author(s):  
P. Czermak ◽  
M. Ebrahimi ◽  
G. Catapano
Keyword(s):  
Produced Water ◽  
Membrane Separation ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Operating Conditions ◽  
Biofilm Growth ◽  
Removal Capacity ◽  
Cross Flow Filtration ◽  
New Generation ◽  
Dialysis Water

Poor water properties, use of concentrated bicarbonate, and biofilm growth in pipes and storage tanks often cause dialysis water and dialysate contamination with bacteria and endotoxins. High-flux dialysis with bicarbonate may favor endotoxin transfer from the dialysate into the blood exposing patients to serious short - and long-term side effects. Ultrafiltration across hydrophobic synthetic membranes effectively removes endotoxins from dialysis water by combined filtration and adsorption. However, repeated sterilization worsens the membrane separation properties, and limits their use. Ceramic membranes are generally more resistant to harsh operating conditions than polymeric membranes, and may represent an alternative for endotoxin removal. Previously, we proved that the ceramic membranes commercially available at that time were not retentive enough to ensure production of endotoxin-free dialysis water. In this paper, we investigated the endotoxin removal capacity of new generation commercial ceramic membranes with nominal molecular weight cut-off down to 1,000. In dead-end filtration, all investigated membranes produced water meeting, the European standards, or close to, when challenged with low endotoxin concentrations, but only one membrane type succeeded at high endotoxin concentrations. In cross-flow filtration, none produced water meeting the European standard. Moreover, sterilization and rinsing procedures altered the separation properties of two out of three membrane types.

scholarly journals Innovative Optical-Sensing Technology for the Online Fouling Characterization of Silicon Carbide Membranes during the Treatment of Oily Water

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1161
Author(s):  
Mehrdad Ebrahimi ◽  
Axel A. Schmidt ◽  
Cagatay Kaplan ◽  
Oliver Schmitz ◽  
Peter Czermak
Keyword(s):  
Silicon Carbide ◽  
Oil Recovery ◽  
Oil And Gas ◽  
Produced Water ◽  
Cross Flow ◽  
Oil And Gas Industry ◽  
Ceramic Membranes ◽  
Transmembrane Pressure ◽  
Sensing Technology ◽  
Water Sensor

The oil and gas industry generates a large volume of contaminated water (produced water) which must be processed to recover oil before discharge. Here, we evaluated the performance and fouling behavior of commercial ceramic silicon carbide membranes in the treatment of oily wastewaters. In this context, microfiltration and ultrafiltration ceramic membranes were used for the separation of oil during the treatment of tank dewatering produced water and oily model solutions, respectively. We also tested a new online oil-in-water sensor (OMD-32) based on the principle of light scattering for the continuous measurement of oil concentrations in order to optimize the main filtration process parameters that determine membrane performance: the transmembrane pressure and cross-flow velocity. Using the OMD-32 sensor, the oil content of the feed, concentrate and permeate streams was measured continuously and fell within the range 0.0–200 parts per million (ppm) with a resolution of 1.0 ppm. The ceramic membranes achieved an oil-recovery efficiency of up to 98% with less than 1.0 ppm residual oil in the permeate stream, meeting environmental regulations for discharge in most areas.

scholarly journals Effect of Permeate Drag Force on the Development of a Biofouling Layer in a Pressure-Driven Membrane Separation System

2008 ◽  
Vol 74 (23) ◽  
pp. 7338-7347 ◽  
Author(s):  
L. Eshed ◽  
S. Yaron ◽  
C. G. Dosoretz
Keyword(s):  
Fluorescent Protein ◽  
Membrane Separation ◽  
Three Dimensional ◽  
Cross Flow ◽  
Luria Bertani ◽  
Confocal Scanning Laser Microscopy ◽  
Permeate Flux ◽  
Cross Flow Filtration ◽  
Confocal Scanning Laser ◽  
Biofilm Development

ABSTRACT The effect of permeate flux on the development of a biofouling layer on cross-flow separation membranes was studied by using a bench-scale system consisting of two replicate 100-molecular-weight-cutoff tubular ultrafiltration membrane modules, one that allowed flow of permeate and one that did not (control). The system was inoculated with Pseudomonas putida S-12 tagged with a red fluorescent protein and was operated using a laminar flow regimen under sterile conditions with a constant feed of diluted (1:75) Luria-Bertani medium. Biofilm development was studied by using field emission scanning electron microscopy and confocal scanning laser microscopy and was subsequently quantified by image analysis, as well as by determining live counts and by permeate flux monitoring. Biofilm development was highly enhanced in the presence of permeate flow, which resulted in the buildup of complex three-dimensional structures on the membrane. Bacterial transport toward the membrane by permeate drag was found to be a mechanism by which cross-flow filtration contributes to the buildup of a biofouling layer that was more dominant than transport of nutrients. Cellular viability was found to be not essential for transport and adhesion under cross-flow conditions, since the permeate drag overcame the effect of bacterial motility.

A Tubular Cross-Flow Filtration Module Based on Chaotic Advection

2015 ◽  
Author(s):  
T. G. Kang ◽  
K. T. Park ◽  
S. U. Kim
Keyword(s):  
Turbulent Flows ◽  
Three Dimensional ◽  
Cross Flow ◽  
Operating Conditions ◽  
Membrane Module ◽  
Chaotic Advection ◽  
Thin Plates ◽  
Tubular Membrane ◽  
Cross Flow Filtration ◽  
Wide Range

We propose a tubular membrane module with embedded three-dimensional structures which is efficient in a wide range of operating conditions (covering both laminar and turbulent flows). Thin plates with barriers are inserted periodically in the circular channel geometry, leading to chaotic advection in a spatially periodic channel flow. Using a numerical scheme combining a particle-tracking and the finite element method, the insert geometry is optimized. The performance of the newly proposed membrane module is assessed by experiments. The membrane module with embedded inserts is found to be better in performance than an ordinary tubular membrane module.

scholarly journals Extraction of laminarin from Saccharina latissima seaweed using cross-flow filtration

2021 ◽  
Author(s):  
Martin Sterner ◽  
Fredrik Gröndahl
Keyword(s):  
Molecular Weight ◽  
Microbial Degradation ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Saccharina Latissima ◽  
Dilute Acid ◽  
Liquid Pressure ◽  
Acid Pretreatment ◽  
Cross Flow Filtration ◽  
Flow Filtration

AbstractLaminarin is a low-molecular-weight polysaccharide found in seaweed (kelp), often in equal concentrations to that in the commercially important hydrocolloid alginate. However, while alginate can be easily recovered by dissolution followed by acid precipitation, for laminarin, there is no such straightforward way of recovering it. Laminarin can be used as dietary fiber and, if efficiently extracted, it may be used for functional food/feed applications and as a component in plant defense stimulants for agriculture. One way of concentrating laminarin from dilute solutions is to press the solution through ultrafine membranes that the molecules cannot pass through. When alginate is extracted, an acid pretreatment step is used and the dilute acid residue from that process also contains laminarin. We used cross-flow filtration to concentrate laminarin fromSaccharina latissima, retrieving it from the dilute acid solution of the acid pretreatment of an alginate extraction. Three ceramic membranes with 5, 15, and 50 kDa molecular weight cutoffs were used, and the pressure, temperature, and feed velocity were altered to reveal which parameters controlled the flow through the membrane and how efficiently laminarin was concentrated. The effects on laminarin extraction for fresh vs. frozen biomass were evaluated showing that frozen biomass releases more laminarin with a similar biomass homogenization technique. Thermal and microbial degradation of the feed components was studied during the course of the filtrations, showing that microbial degradation can affect the laminarin concentration, while the temperature of the process ~ 65 °C had little impact on laminarin. The techniques used to monitor the components in the feed and permeate during filtration were nuclear magnetic resonance,1H-NMR, and size exclusion chromatography. The filtrations were performed in a pilot-size filtration unit with ceramic membranes (ZrO2/TiO2, TiO2-Al2O support, 0.08 m2). To be able to operate without quick membrane fouling, the most important parameter was to have a high liquid velocity over the membrane, 4.7 m s−1. A good technique to concentrate laminarin was to prefilter it through a 50-kDa membrane using 2 bar liquid pressure and to concentrate it over a 5-kDa membrane using 5-bar liquid pressure. With these settings, the liquid flux through the filter became 60–80 and 30–40 L m−2 h−1over the 50-kDa and 5-kDa membrane.

scholarly journals Dynamic cross-flow filtration of oilfield produced water by rotating ceramic filter discs

2013 ◽  
Vol 51 (7-9) ◽  
pp. 1762-1768 ◽  
Author(s):  
M. Ebrahimi ◽  
O. Schmitz ◽  
S. Kerker ◽  
F. Liebermann ◽  
P. Czermak
Keyword(s):  
Produced Water ◽  
Cross Flow ◽  
Ceramic Filter ◽  
Cross Flow Filtration ◽  
Oilfield Produced Water ◽  
Flow Filtration

Cross-flow filtration of methane fermentation broth by ceramic membranes

1989 ◽  
Vol 68 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Takuo Imasaka ◽  
Nobuhiko Kanekuni ◽  
Hiroyuki So ◽  
Shigeru Yoshino
Keyword(s):  
Fermentation Broth ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Methane Fermentation ◽  
Cross Flow Filtration ◽  
Flow Filtration

Cross-flow Filtration through Ceramic Membranes of Enzymes and Degradation Products from Enzymatic Peeling of Satsuma Mandarin Segments

2008 ◽  
Vol 14 (5_suppl) ◽  
pp. 71-76 ◽  
Author(s):  
M. Moliner ◽  
D. Saura ◽  
J.M. Ros ◽  
J. Laencina
Keyword(s):  
Molecular Weight ◽  
Pore Size ◽  
Degradation Products ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Satsuma Mandarin ◽  
Cross Flow Filtration ◽  
Enzymatic Peeling ◽  
Commercial Enzymes ◽  
Flow Filtration

The present work evaluates the possibility of using cross-flow filtration to recover enzymatic activities from commercial enzymes used for peeling mandarin segments. Two ceramic membranes of different pore size and molecular weight cut-off were assayed. The membrane of 40 kDa molecular weight cut-off provided better separation of enzymes and carbohydrates than the membrane of 0.14 μm pore size, since the enzymes were readily retained in the retentate fraction, while carbohydrates easily passed into the permeate fraction. After separation, both fractions (enzymes and carbohydrates) could be further used.

Evaluation of Virus Removal in Membrane Separation Processes Using Coliphage Qβ

1993 ◽  
Vol 28 (7) ◽  
pp. 9-15 ◽  
Author(s):  
Taro Urase ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki
Keyword(s):  
Membrane Separation ◽  
Membrane Surface ◽  
Cross Flow ◽  
Pond Water ◽  
High Concentration ◽  
Separation Processes ◽  
Surface Deposit ◽  
Virus Removal ◽  
Cross Flow Filtration ◽  
Flow Filtration

Virus removal in membrane separation processes was investigated by employing coliphage Qβ as a tracer. Several types of microfiltration membrane and ultrafiltration membrane were tested. Two types of filtration experiments were carried out; dead-end filtration and cross-flow filtration. The membrane surface deposits played an important role in the rejection of viruses in the filtration of activated sludge and pond-water, whereas acrylate polymer cake did not affect the rejection of Qβ. The leakage of ultrafiltration membranes was well examined by the high concentration of Qβ applied. The major part of the rejected coliphages were adsorbed onto the membrane and in its surface deposit.

Sign in / Sign up

Export Citation Format

Share Document