Death, Taxes . . . and RO Membrane Fouling

- By:

Courtesy of

Membrane fouling in reverse osmosis (RO) systems is as all pervasive and inevitable as the common cold. Avoidance is just as hit-or-miss: wash your hands, don't get your feet wet and hope for the best. The many unseen factors influencing whether a person becomes ill parallel the many variables that determine the onset and severity of fouling in a membrane system. Design, operation, and maintenance all play a role. Accepting that fouling is inevitable is the first step in effectively anticipating, compensating for and counteracting the fouling phenomena. Ultimately, this mindset can help operators keep their systems as 'healthy' as possible.

Fouling is a broad, generic term used to identify a multitude of time-dependent phenomena, which, singly or in combination, impact membrane performance. Just as illness can take many forms -- from a relatively mild cold to life-threatening cancer-- fouling also can have a range of effects.

Some degree of fouling has already been accounted for in any properly designed system. From a practical standpoint, fouling is of interest only when it negatively affects a system's productivity.

Calculations such as the Langelier saturation index (LSI) or silt density index (SDI), found in ASTM standards D4189-94 and D3739-94, respectively, can provide insight into the fouling problems that are inherent in any membrane system. Ideally, these calculations are used in the original design of the system. However, operators may find it useful to work through the calculations to anticipate the potential effects of a system upset.

Customer comments

No comments were found for Death, Taxes . . . and RO Membrane Fouling. Be the first to comment!