ABSTRACT
Membrane filtration is expected to become a pretreatment for other membrane processes. One of the most important aspects of membrane treatment plant design is the source and character of the proposed feedwater. Colloidal sulfur fouling occurs when air is allowed to enter a feedwater system in which hydrogen sulfide is present. The basic requirements for a successful membrane are as follows: good flux characteristics at the lowest pressure possible, good salt rejection, long term stability, reproducible test results, mechanical strength and low cost. Reverse osmosis has long been recognized as an effective tool for organics rejection. Operating costs will vary significantly as a function of feedwater quality. Electrodialysis works by "drawing" positively and negatively charged ions, cations and anions, through a membrane system toward electrodes of the opposite charge, cathode and anode. The entire process is controlled by the following primary relationships: dissociation of salts in water, membrane properties, faraday's law and ohm's law.
