Arsenic contamination, effects and remediation techniques: A special look onto membrane separation processes

Separation of Biologically Active Compounds by Membrane Operations

Current Pharmaceutical Design ◽

10.2174/1381612822666161027153823 ◽

2017 ◽

Vol 23 (2) ◽

pp. 218-230 ◽

Cited By ~ 4

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.

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Membranes and Membrane Separation Processes

Ullmann's Encyclopedia of Industrial Chemistry ◽

10.1002/14356007.a16_187.pub2 ◽

2005 ◽

Cited By ~ 20

Author(s):

Heinrich Strathmann

Keyword(s):

Membrane Separation ◽

Separation Processes

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Application of membrane separation processes in phosphorus recovery: A review

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.144346 ◽

2021 ◽

Vol 767 ◽

pp. 144346

Author(s):

Xiang Li ◽

Shuting Shen ◽

Yuye Xu ◽

Ting Guo ◽

Hongliang Dai ◽

...

Keyword(s):

Membrane Separation ◽

Phosphorus Recovery ◽

Separation Processes

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Analysis of ethanol dehydration using membrane separation processes

Open Life Sciences ◽

10.1515/biol-2020-0013 ◽

2020 ◽

Vol 15 (1) ◽

pp. 122-132 ◽

Cited By ~ 2

Author(s):

Carolina Conde-Mejía ◽

Arturo Jiménez-Gutiérrez

Keyword(s):

Capital Investment ◽

Membrane Separation ◽

Biomass Pretreatment ◽

Ethanol Dehydration ◽

Purification Step ◽

Silica Membrane ◽

Separation Processes ◽

Fermentation Processes ◽

Vapor Permeation ◽

Type Zeolite

AbstractAfter the biomass pretreatment and fermentation processes, the purification step constitutes a major task in bioethanol production processes. The use of membranes provides an interesting choice to achieve high-purity bioethanol. Membrane separation processes are generally characterized by low energy requirements, but a high capital investment. Some major design aspects for membrane processes and their application to the ethanol dehydration problem are addressed in this work. The analysis includes pervaporation and vapor permeation methods, and considers using two types of membranes, A-type zeolite and amorphous silica membrane. The results identify the best combination of membrane separation method and type of membrane needed for bioethanol purification.

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

Water Science & Technology ◽

10.2166/wst.2005.0637 ◽

2005 ◽

Vol 51 (6-7) ◽

pp. 181-192 ◽

Cited By ~ 18

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.

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