Modelling and Simulation of Nanofiltration MembranesGamze Artug
Taschenbuch
Nanofiltration ( N F) is a relatively recent membrane process and offers a plethora of application areas due to its selective removal for ions and removal of organic matter above 200 g/mol molar mass. Application fields enlarged substantially in the last 25 years. Accordingly, there is an increasing need for process design and optimisation tools. Therefore, current research studiesfocus on a better understanding of mass transport phenomenon as well as the application and enhancement of the existing models to the real process streams.
In this thesis work, characterisation of N F membranes and investigations of their mass transport phenomenon through both experimental and modelling studies were of concern. For these purposes, flat sheet samples of four commercially available membranes were selected. Since the performance of a N F membrane is related to its structural and charge properties, membrane characterisation studies by microscopy, contact angle and electrokinetic measurements were conducted. A systematic experimental program was applied covering a wide spectrum of feed streams concerning both charged and uncharged solutes. Particularly charged streams regarding
single salts and their mixtures were emphasised. Moreover, the effects of the operating conditions and the solution p H on membrane performances were investigated. Standard performance characterisation experiments, consisting of pure water permeability, organic and single salt rejection measurements, gave initial information on the membrane charge and performance characteristics. In mixture solutions of salts, distinctive behaviours of membranes to different ion types at different combinations were observed. Furthermore, artificial seawater experiments were conducted in order to determine the convenience of the considered N F membranes for this recently recognised process as an intensification step in the pre-treatment of seawater.
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