scholarly journals The chemical cleaning of ceramic membrane used in UF

2012 ◽  
Vol 14 (3) ◽  
pp. 105-109 ◽  
Author(s):  
Maria Tomaszewska ◽  
Lidia Białończyk
Keyword(s):  
Food Industry ◽  
Ceramic Membrane ◽  
Fermentation Broth ◽  
Membrane Surface ◽  
Membrane Properties ◽  
Chemical Cleaning ◽  
Cleaning Procedure ◽  
Essential Step ◽  
Uf Membranes ◽  
Optimum Recovery

Ultrafiltration (UF) is one of the membrane processes which is mostly used in the dairy industry for the separation and concentration of whey components or fermentation broth. Fouling of UF membranes in the food industry is primarily due to a deposition of microorganisms, proteins, fats and minerals on the membrane surface. Thus, cleaning of the membranes is an essential step of UF separation. The results from investigations of chemical cleaning of a ceramic UF membrane fouled by precipitation of whey components and yeast contained in the fermentation broth are presented. The effect of cleaning procedure on the degree of permeability restoration by the fouled membrane was studied. The results demonstrated that a combination of sodium hydroxide, phosphoric acid and sodium hypochlorite as a disinfectant could be successfully used to achieve an optimum recovery of the membrane properties.

scholarly journals Influence of Ceramic Membrane Surface Characteristics on the Flux Behavior of a Complex Fermentation Broth

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 402
Author(s):  
Nicolas A. P. Maguire ◽  
Mehrdad Ebrahimi ◽  
Rong Fan ◽  
Sabine Gießelmann ◽  
Frank Ehlen ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Ceramic Membrane ◽  
Mechanical Stability ◽  
Fermentation Broth ◽  
Membrane Surface ◽  
Surface Characteristics ◽  
Ceramic Membranes ◽  
Ultrafiltration Membranes ◽  
Wall Shear

The valorization of agro-industrial residues using yeasts as biocatalysts requires efficient methods for biomass separation. Filtration with ceramic membranes is suitable for this task, however, the challenge of flux decline and the unavoidable cleaning must be taken into account. We investigated the filtration of fermentation broth and its components using tubular microfiltration and ultrafiltration membranes, and hollow-fiber ultrafiltration membranes, with cut-offs of 30 and 200 nm. The steady-state flux was limited by fouling under comparable wall shear stress conditions but increased when the wall shear stress was higher. Single-component filtration with two 30 nm tubular ultrafiltration membranes, whose average surface roughness ranged from 1.0 to 3.9 µm, showed that smoother surfaces experience less biomass fouling under more intense hydrodynamic conditions. Furthermore, we showed experimentally and by scanning electron microscopy in filtration with 30 nm tubular membranes that the thickness of the first separation layer is responsible for the degree of irreversible resistance caused by the deposition of organic material in the membrane pores. The thickness of this layer should therefore be minimized without compromising mechanical stability.

Effect of Process Factors on Pervaporation Dehydration of Isopropanol

2017 ◽  
Vol 68 (6) ◽  
pp. 1302-1305
Author(s):  
Ali A. A. Al Janabi ◽  
Oana Cristina Parvulescu ◽  
Bogdan Trica ◽  
Tanase Dobre
Keyword(s):  
Ceramic Membrane ◽  
Membrane Surface ◽  
Water System ◽  
Surface Model ◽  
Feed Water ◽  
Mixture Flow ◽  
Water Separation ◽  
Membrane Area ◽  
Operation Temperature ◽  
Process Factors

The paper aimed at studying the performances of pervaporation separation of isopropanol-water system using a Pervatech ceramic membrane at various values of feed mixture flow rate (F=1000 kg/hr), feed water mass fraction (xF=0.1-0.2), operation temperature (t=60-90 �C), permeate pressure (pP=1000-9000 Pa) and water separation degree (sW=0.9, 0.95). Membrane total flux and separation factor were predicted applying a second order response surface model with 3 factors, i.e., xF, t and pP. An algorithm for estimating the membrane surface area was presented. Membrane area increased with sW and xF and its lowest values (A=13 m2 for xF=0.1 and A=24 m2 for xF=0.2) were attained for t=60 �C and pP=9000 Pa. These findings could be applied for optimizing the process of isopropanol dehydration by pervaporation.

Low-pressure membrane filtration with unconventional coagulation regimes

2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Cross Flow ◽  
Chemical Cleaning ◽  
Sand Filters ◽  
Charge Neutralization ◽  
Floc Size ◽  
Filtration System ◽  
Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

Orange juice ultrafiltration: characterisation of deposit layers and membrane surfaces after fouling and cleaning

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Hainiza Abd-Razak ◽  
Y. M. John Chew ◽  
Michael R. Bird
Keyword(s):  
Shear Stress ◽  
Orange Juice ◽  
Surface Coverage ◽  
Fluid Shear Stress ◽  
Membrane Surface ◽  
Regenerated Cellulose ◽  
Fluid Shear ◽  
Chemical Cleaning ◽  
Membrane Area ◽  
Software Analysis

Abstract The influence of feed condition and membrane cleaning during the ultrafiltration (UF) of orange juice for phytosterol separation was investigated. UF was performed using regenerated cellulose acetate (RCA) membranes at different molecular weight cut-off (MWCO) values with a 336 cm2 membrane area and a range of temperatures (10–40 °C) and different feed volumes (3–9 L). Fluid dynamic gauging (FDG) was applied to assess the fouling and cleaning behaviours of RCA membranes fouled by orange juice and cleaned using P3-Ultrasil 11 over two complete cycles. During the FDG testing, fouling layers were removed by fluid shear stress caused by suction flow. The cleanability was characterised by using ImageJ software analysis. A Liebermann-Buchard-based method was used to quantify the phytosterol content. The results show that RCA 10 kDa filters exhibited the best separation of phytosterols from protein in orange juice at 20 °C using 3 L feed with a selectivity factor of 17. Membranes that were fouled after two cycles showed higher surface coverage compared to one fouling cycle. The surface coverage decreased with increasing fluid shear stress from 0 to 3.9 Pa. FDG achieved 80–95% removal at 3.9 Pa for all RCA membranes. Chemical cleaning using P3-Ultrasil 11 altered both the membrane surface hydrophobicity and roughness. These results show that the fouling layer on RCA membranes can be removed by fluid shear stress without affecting the membrane surface modification caused by chemical cleaning.

Surface modification of reverse osmosis membranes with zwitterionic polymer to reduce biofouling

2015 ◽  
Vol 15 (5) ◽  
pp. 999-1010 ◽  
Author(s):  
Ahmed E. Abdelhamid ◽  
Mahmoud M. Elawady ◽  
Mahmoud Ahmed Abd El-Ghaffar ◽  
Abdelgawad M. Rabie ◽  
Poul Larsen ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Tap Water ◽  
Membrane Surface ◽  
Salt Content ◽  
Cross Flow ◽  
Membrane Properties ◽  
Cleaning Efficiency ◽  
Bacteria Growth ◽  
Cross Flow Filtration

The zwitterionic homopolymer poly[2-(methacryloyloxy)ethyl-dimethyl-(3-sulfopropyl) ammonium hydroxide was coated onto the surface of commercial polyamide reverse osmosis (RO) membranes. Aqueous solutions of the polymer at different concentrations were applied to modify the polyamide membranes through an in situ surface coating procedure. After membrane modification, cross-flow filtration testing was used to test the antifouling potential of the modified membranes. The obtained data were compared with experimental data for unmodified membranes. Each test was done by cross-flow filtering tap water for 60 hours. Yeast extract was added as a nutrient source for the naturally occurring bacteria in tap water, to accelerate bacteria growth. Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, atomic force microscopy, and permeation tests were employed to characterize membrane properties. The results confirmed that modifying the membranes enhanced their antifouling properties and cleaning efficiency, the fouling resistance to bacteria improving due to the increased hydrophilicity of the membrane surface after coating. In addition, the water permeability and salt rejection improved. This in situ surface treatment approach for RO membranes could be very important for modifying membranes in their original module assemblies as it increases water production and reduces the salt content.

scholarly journals Diethylene Glycol-Assisted Organized TiO2 Nanostructures for Photocatalytic Wastewater Treatment Ceramic Membranes

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 750 ◽  
Author(s):  
Ahmad ◽  
Kim ◽  
Kim ◽  
Kim
Keyword(s):  
Wastewater Treatment ◽  
Diethylene Glycol ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Ceramic Membranes ◽  
Tio2 Nanorods ◽  
Hydrolysis Rate ◽  
Capping Agent ◽  
Alumina Support

A high-performance photocatalytic ceramic membrane was developed by direct growth of a TiO2 structure on a macroporous alumina support using a hydrothermal method. The morphological nanostructure of TiO2 on the support was successfully controlled via the interaction between the TiO2 precursor and a capping agent, diethylene glycol (DEG). The growth of anatase TiO2 nanorods was observed both on the membrane surface and pore walls. The well-organized nanorods TiO2 reduced the perturbation of the alumina support, thus controlling the hydrolysis rate of the TiO2 precursor and reducing membrane fouling. However, a decrease in the amount of the DEG capping agent significantly reduced membrane permeability, owing to the formation of nonporous clusters of TiO2 on the support. Distribution of the organized TiO2 nanorods on the support was very effective for the improvement of the organic removal efficiency and antifouling under ultraviolet illumination. The TiO2 nanostructure associated with the reactive crystalline phase, rather than the amount of layered TiO2 formed on the support, which was found to be the key to controlling photocatalytic membrane reactivity. These experimental findings would provide a new approach for the development of efficacious photocatalytic membranes with improved performance for wastewater treatment.

scholarly journals Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Pure Water ◽  
Ex Situ ◽  
Stable Operation ◽  
Chemical Cleaning ◽  
Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

Polysulfone Activated Carbon Composite Membranes

2010 ◽  
Vol 660-661 ◽  
pp. 1081-1086 ◽  
Author(s):  
Priscila Anadão ◽  
Laís Fumie Sato ◽  
Hélio Wiebeck ◽  
Francisco Rolando Valenzuela-Díaz
Keyword(s):  
Activated Carbon ◽  
Membrane Surface ◽  
Composite Membranes ◽  
Carbon Composite ◽  
Van Der Waals Interactions ◽  
Membrane Properties ◽  
Mechanical Resistance ◽  
Scanning Electron Micrographs ◽  
Polysulfone Membrane ◽  
Hydrophilic Material

The addition of a fourth component in the system composed by polymer/ solvent/ non-solvent is a technique generally employed to enhance membrane properties. Since polysulfone presents low hydrophilicity, which can hamper filtration performance, the addition of a hydrophilic material can be an important technique to improve this property. Therefore, the main purpose of this work is to understand the influence of addition of the activated carbon in the system polysulfone/ NMP/ water in terms of membrane morphology, hydrophilicity, thermal and mechanical resistance. From scanning electron micrographs, it could be seen that membrane surface became denser with the addition of higher activated carbon contents and the cross-section morphology was not changed. Acid-base interactions were favored with the activated carbon addition and the availability of Lifshtiz-van Der Waals interactions was decreased, being these two properties very important to avoid fouling formation onto membrane surface. The glass transition temperatures of the polysulfone composite membranes with higher activated carbon contents were increased. However, all activated carbon contents brittled the composite membranes in relation to the pristine polysulfone membrane.

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