Reverse osmosis nanofiltration membrane

Wilbert, M.C., Pellegrino, J., and Zydney, A., Bencb-scale testing of surfactant-modified reverse osmosis/nanofiltration membranes. Desalination, 115(1), 15, 1998. 

Singh, Rajindar (M.A.E. Environmental Technologies). A Review of Membrane Technologies Reverse Osmosis, Nanofiltration and Ultrcfiltration. Ultrapure Water, Tall Oaks Publishing, Inc., USA, March 1997. 

Membrane filtration (reverse osmosis, nanofiltration, ultrafiltration, microfiltration)... 

In temperate climate zones it may be more appropriate to install a nanofiltration process rather than reverse osmosis. Nanofiltration allows the production of drinking water from polluted rivers. As for reverse osmosis, pretreatment is important to control fouling of the membranes. One of the largest such plants produces 140,000 m3/day of water for the North Paris region(26). 

H. Dach, J. Leparc, H. Suty, C. Diawara, A. Jadas-Hecart, A. Lhassani, M. Pontie, Innovative approach for characterization of nanofiltration (NF) and low pressure reverse osmosis (LPRO) membranes for brackish water desalination, Desalination, 2006 (submitted). 

Conventional methods for treating wastewater containing dyes, aromatic compounds, or heavy metals are coagulation, flocculation, reverse osmosis, nanofiltration and pervaporation (Paul and Ohlrogge, 1998), and activated carbon adsorption, the latter of which is combined with membrane processes like nanofiltration (Eilers and Melin, 1999) or ultrafiltra-tion (Lenggenhager and Lyndon, 1997). 

Membrane technology used in water reclamation includes five major membrane types reverse osmosis, nanofiltration, ultrafiltration, microfiltration, and liquid membranes. These five types of membranes are discussed briefly, and examples of their applications in municipal and industrial wastewater reclamation is also described. 

Membranes are used for a wide variety of separations. A membrane serves as a barrier to some particles while allowing others to selectively pass through. The pore size, shape, and electrostatic surface charge are fundamental to particle removal. Synthetic polymers (cellulose acetate, polyamides, etc.) and inorganic materials (ceramics, metals) are generally the principal materials of construction. Membranes may be formed with symmetric or asymmetric pores, or formed as composites of ultra thin layers attached to coarser support material. Reverse osmosis, nanofiltration, ultrafiltration, and microfiltration relate to separation of ions, macromolecules, and particles in the 0.001 to 10 pm range (Rushton et al. 1996). 

The concept of coupling reaction with membrane separation has been applied to biological processes since the seventies. Membrane bioreactors (MBR) have been extensively studied, and today many are in industrial use worldwide. MBR development was a natural outcome of the extensive utilization membranes had found in the food and pharmaceutical industries. The dairy industry, in particular, has been a pioneer in the use of microfiltra-tion (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes. Applications include the processing of various natural fluids (milk, blood, fruit juices, etc.), the concentration of proteins from milk, and the separation of whey fractions, including lactose, proteins, minerals, and fats. These processes are typically performed at low temperature and pressure conditions making use of commercial membranes. 

Likewise, nanofiltration can be integrated into waste water treatment. Combined reverse osmosis/nanofiltration processes can offer higher water recovery than either process alone [122]. Moreover, nanofiltration can be combined with other membrane filtration processes [123], electrodialysis [124], or other waste water treatment processes such as ozonation [125]. 

Finally, in Chap. 8, attempts are made to correlate the AFM parameters, such as nodule and pore sizes, to the membrane performance data. Membranes used for a variety of membrane processes, including reverse osmosis, nanofiltration, ultrafiltration, microfiltration, gas and vapor separation, pervaporation, and other membrane separation processes, are covered in this chapter. AFM parameters are also correlated to membrane biofouhng. This chapter also includes appUcations of AFM to characterize biomedical materials, including artificial organs cind drug release. 

UF, MF, nanofiltration, reverse osmosis flat membrane/dead-end Enzymatic interesterification between triacylglycerols and polyimsatmated fatty acids [154]... 

Integrated membrane process for seawater desalination. MF = microfiltration UF = ultrafiltration NF = nanofiltration MC = membrane contactor RO = reverse osmosis MD = membrane distillation. 

Reverse osmosis, nanofiltration, and ultrafUtration are typically used in the cross-flow configuration, where the feed stream flows across or tangential to the membrane surface. The constant flow across the membrane surface minimizes the buildup in concentration of salts at the membrane surface for reverse osmosis and nanofiltration products, and inhibits the formation of a gel or particulate layer for ultrafUtration and microfUtration products. The permeate passes through the membrane, and the concentrate or retentate retains the dissolved and suspended solids rejected by the membrane. 

Ahmad Fauzi Ismail (development of membrane technology for reverse osmosis, nanofiltration, ultrafiltration and membrane contactor). Deputy Vice Chancellor (Research Innovation) Founder and Director, Advanced Membrane Technology Research Center (AMTEC), University of Technology Malaysia (UTM), Johor Bahru,... 

Diawara, C.K., Diop, S.N., Diallo, M.A, Farcy, M. Deratani, A. (2011) Performance of nanofiltration (NF) and low pressure reverse osmosis (LPRO) membranes in the removal of fluorine and salinity from brackish drinking water. Jourrud of Water Resource and Protection, 3,912-917. 

Yoon, X, Amy, G., Chung, X, Sohn, X Yoon, Y. (2009) Removal of toxic ions (chromate, arsenate, and perchlorate) using reverse osmosis, nanofiltration, and ultrafiltration membranes. Chemosphere, 11 (2), 228-235. 

Chapter 9 will include all aspects of apphcations of carbon related membranes in separation processes such as reverse osmosis, nanofiltration, pervaporation, gas separation and fuel ceU. 

Membrane type Reverse osmosis Nanofiltration Ultrafiltration Microfiltration— ... 

This book was planned to commemorate the announcement of the first cellulose acetate membrane for reverse osmosis by Loeb and Sourirajan in 1960, which triggered R D activities for seawater desalination by membrane and eventually resulted in emergence of a novel industrial separation process. Membrane separation technologies that include reverse osmosis, nanofiltration, ultrafiltarion, membrane gas and vapor separation, pervaporation, membrane extraction, membrane distillation, bipolar membrane and others, touch nowadays all aspects of human life since they are applied in various branches of industries such as chemical process, petrochemical and petroleum, pharmaceutical, environmental and food processing industries. 

Reverse osmosis models can be divided into three types irreversible thermodynamics models, such as Kedem-Katchalsky and Spiegler-Kedem models nonporous or homogeneous membrane models, such as the solution—diffusion (SD), solution—diffusion—imperfection, and extended solution—diffusion models and pore models, such as the finely porous, preferential sorption—capillary flow, and surface force—pore flow models. Charged RO membrane theories can be used to describe nanofiltration membranes, which are often negatively charged. Models such as Dorman exclusion and the... 

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