Methods to Reduce Concentration Polarization and Fouling in Membrane Filtration

1994 ◽  
Vol 59 (4) ◽  
pp. 737-755 ◽  
Author(s):  
Petr Mikulášek
Keyword(s):  
Membrane Filtration ◽  
Morphological Analysis ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Separation Processes ◽  
Membrane Modules

Various methods and concepts that are currently being used and proposed to control or minimize concentration polarization and fouling in membrane separation processes are reviewed. A morphological analysis of hydrodynamic ways to prevent the detrimental influence on fluxes is given. The potentials of these different approaches are analyzed and some examples of module designs resulting from the various approaches with special attention to rotary membrane modules are given.

Biofilms: their structure, activity, and effect on membrane filtration

2005 ◽  
Vol 51 (6-7) ◽  
pp. 181-192 ◽  
Author(s):  
Z. Lewandowski ◽  
H. Beyenal
Keyword(s):  
Membrane Filtration ◽  
Membrane Separation ◽  
Separation Processes ◽  
Membrane Cleaning ◽  
Underlying Assumption ◽  
Structure Activity ◽  
Membrane Biofouling ◽  
Flux Decline ◽  
Cleaning Procedures ◽  
Near Future

The goal of this presentation is to identify biofouling mechanisms that cause undesirable effects to the membrane separation processes of flux decline and pressure drop. The underlying assumption of this presentation is that biofouling is unavoidable and that the operator cannot eliminate it entirely. This premise justifies research efforts toward understanding the mechanisms by which biofouling affects the membrane processes, rather than expecting that technology can entirely eliminate membrane biofouling in the near future. An improved understanding of biofouling mechanisms may lead to better membrane design, better membrane modules, and better membrane cleaning procedures.

The Effect of Flow Pulsation on Ultrafiltration System Limiting Flux Behavior

2013 ◽  
Author(s):  
Chyouhwu Brian Huang ◽  
Hung-Shyong Chen
Keyword(s):  
Membrane Filtration ◽  
Concentration Polarization ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Paper Industry ◽  
Surface Concentration ◽  
Permeate Flux ◽  
Filtration Time ◽  
Protection Systems ◽  
Oil Water

Ultrafiltration (UF) is an important industrial operation and is found in the food industry, separation of oil-water emulsions, treatment effluents from the pulp and paper industry, and environmental protection systems. Despite being widely used in these areas, UF systems exhibit a limiting flux behavior caused by concentration polarization on the membrane surface. Concentration polarization can be severe in macromolecular solutions due to low diffusivity on membrane separation and both mechanical and chemical methods have been used to reduce this phenomenon. This study introduces a new mechanical method that improves the performance of membrane separation and decreases concentration polarization. It involves pulsing the feed flow discontinuously and based on our results, feed flow velocity and solution bypass/membrane filtration time ratio are two vital factors when it comes to improving permeate flux. The proposed method is expected to find wide application, particularly in the processing of macromolecular solution.

scholarly journals Permeate Flux in Ultrafiltration Membrane: A Review

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
A. Beicha ◽  
R. Zaamouch ◽  
N. M. Sulaiman
Keyword(s):  
Membrane Filtration ◽  
Membrane Separation ◽  
Size Range ◽  
Membrane Surface ◽  
Separation Performance ◽  
Permeate Flux ◽  
Predictive Capability ◽  
Separation Processes ◽  
Ultrafiltration Pressure ◽  
Rate Limiting

Membrane processes exist for most of the fluid separations encountered in industry. The most widely used is membrane ultrafiltration, pressure driven process which is capable of separating particles in the approximate size range of 0.001 to 0.1 μm. The design of membrane separation processes, like all other processes, requires quantitative expressions relating material properties to separation performance. The factors controlling the performance of ultrafiltration are extensively reviewed. There have been a number of seminal approaches in this field. Most have been based on the rate limiting effects of the concentration polarization of the separated particles at the membrane surface. Various rigorous, empirical and intuitive models exist, which have been critically assessed in terms of their predictive capability and applicability. The decision as to which of the membrane filtration models is the most correct in predicting permeation rates is a matter of difficulty and appears to depend on the nature of the dispersion to separated.

scholarly journals Manganese in the source of groundwater in Malaysia and the method for the removal process: A review on the adsorption and membrane separation processes

2021 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Norin Zamiah Kassim Shaari ◽  
Ahmed Qutb Akmal Sajali
Keyword(s):  
Drinking Water ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Memory Loss ◽  
Motor Dysfunction ◽  
Activated Carbon Adsorption ◽  
Filtration Process ◽  
Separation Processes ◽  
Adsorptive Membrane ◽  
High Level

In Malaysia, the quality of groundwater as one of the main sources drinking water is deteriorated due to the presence of a high level of manganese, which exceeds the allowable values for drinking water consumption. Manganese at concentration higher than 0.1 mg/L causes staining, high turbidity and bad taste problem in drinking water, and eventually can cause a depletion of brain dopamine and a syndrome of motor dysfunction and memory loss resembling Parkinson disease. Several methods have been used to eliminate manganese from the groundwater, which include precipitation, coagulation, ion exchange, oxidation and filtration, aeration, activated carbon adsorption, ionic liquid extraction and biosorption. Among those methods, adsorption is the most efficient and cheaper method to remove heavy metal as the operation is easily be controlled and the reversible adsorbents can be regenerated through a suitable process. Membrane filtration on the other hand particularly reverse osmosis and nanofiltration have been found to be a very effective and economical way to isolate components that are suspended or dissolved in a liquid. In addition to that, the combination of adsorption and membrane filtration process such as polymer enhanced ultrafiltration and adsorptive membrane respectively are currently attracted attentions. This paper provides a review on the adsorption process and membrane filtration process for manganese removal, with subsequently outlining the potential adsorbents to be incorporated in the fabrication of adsorptive membrane.

scholarly journals Purification of Dairy Wastewaters by Advanced Oxidation Processes and Membrane Filtration

2017 ◽  
Vol 11 (1) ◽  
pp. 32-38
Author(s):  
Mihály Zakar ◽  
Erika Lakatos ◽  
Gábor Keszthelyi-Szabó ◽  
Zsuzsanna László
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
Scale Up ◽  
Separation Processes ◽  
Physicochemical Changes ◽  
Current Trends ◽  
Pre Treatment ◽  
Cost Efficient

Membrane separation processes are space and cost-efficient, easy to scale-up operations, which have proved to treat food industrial wastewaters efficiently. Beside the advantages like high separation efficiency without any chemical changes and low energy-intensity, membrane filtration also has drawbacks, like decreased operational efficiency caused by flux decile resulting from fouling and concentration polarization. Combination of oxidation pre-treatment and membrane filtration is a promising method for decreasing fouling due to the physicochemical changes caused by pre-oxidation of the wastewater in structure of colloidal pollutants and in the interactions between the foulants and the membrane material. The aim of this work is to identify the parameters affecting the membrane fouling during treatment of dairy wastewaters, and present the current trends of research in this field.

Fundamental aspects of centrifugal membrane separation

2001 ◽  
Vol 215 (4) ◽  
pp. 355-365
Author(s):  
A Bergen ◽  
P M Wild ◽  
N Djilali ◽  
G W Vickers
Keyword(s):  
Experimental Investigation ◽  
Membrane Filtration ◽  
Concentration Polarization ◽  
Energy Savings ◽  
Membrane Separation ◽  
Dynamic Environment ◽  
Separation Process ◽  
Filtration Process ◽  
Membrane Performance ◽  
Centrifuge Rotor

A new membrane filtration process which uses the dynamic environment created on board a centrifuge rotor to enhance the performance of the separation process is described. Centrifugal membrane separation (CMS) combines the energy savings associated with centrifugal reverse osmosis (CRO) with the natural alleviation of concentration polarization and fouling due to the dynamic environment. A research centrifuge was constructed to compare the CMS process directly with a conventional process. An experimental investigation was conducted to determine the effects of centripetal and Coriolis acceleration on membrane performance. A description of the apparatus and the experimental results for various membrane orientations are presented. Significant reduction in the fouling rate and virtual elimination of concentration polarization have been shown.

Separation of Biologically Active Compounds by Membrane Operations

2017 ◽  
Vol 23 (2) ◽  
pp. 218-230 ◽  
Author(s):  
Xiaoying Zhu ◽  
Renbi Bai
Keyword(s):  
Energy Consumption ◽  
Bioactive Compounds ◽  
Membrane Fouling ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
High Energy ◽  
Separation Processes ◽  
Membrane Processes ◽  
Separation Technology ◽  
Pressure Driven

Background: Bioactive compounds from various natural sources have been attracting more and more attention, owing to their broad diversity of functionalities and availabilities. However, many of the bioactive compounds often exist at an extremely low concentration in a mixture so that massive harvesting is needed to obtain sufficient amounts for their practical usage. Thus, effective fractionation or separation technologies are essential for the screening and production of the bioactive compound products. The applicatons of conventional processes such as extraction, distillation and lyophilisation, etc. may be tedious, have high energy consumption or cause denature or degradation of the bioactive compounds. Membrane separation processes operate at ambient temperature, without the need for heating and therefore with less energy consumption. The “cold” separation technology also prevents the possible degradation of the bioactive compounds. The separation process is mainly physical and both fractions (permeate and retentate) of the membrane processes may be recovered. Thus, using membrane separation technology is a promising approach to concentrate and separate bioactive compounds. Methods: A comprehensive survey of membrane operations used for the separation of bioactive compounds is conducted. The available and established membrane separation processes are introduced and reviewed. Results: The most frequently used membrane processes are the pressure driven ones, including microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). They are applied either individually as a single sieve or in combination as an integrated membrane array to meet the different requirements in the separation of bioactive compounds. Other new membrane processes with multiple functions have also been developed and employed for the separation or fractionation of bioactive compounds. The hybrid electrodialysis (ED)-UF membrane process, for example has been used to provide a solution for the separation of biomolecules with similar molecular weights but different surface electrical properties. In contrast, the affinity membrane technology is shown to have the advantages of increasing the separation efficiency at low operational pressures through selectively adsorbing bioactive compounds during the filtration process. Conclusion: Individual membranes or membrane arrays are effectively used to separate bioactive compounds or achieve multiple fractionation of them with different molecule weights or sizes. Pressure driven membrane processes are highly efficient and widely used. Membrane fouling, especially irreversible organic and biological fouling, is the inevitable problem. Multifunctional membranes and affinity membranes provide the possibility of effectively separating bioactive compounds that are similar in sizes but different in other physical and chemical properties. Surface modification methods are of great potential to increase membrane separation efficiency as well as reduce the problem of membrane fouling. Developing membranes and optimizing the operational parameters specifically for the applications of separation of various bioactive compounds should be taken as an important part of ongoing or future membrane research in this field.

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

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