Don’t Let Chemical Cleaning Dictate Membrane Life

Membrane life is one of the biggest drivers in life cycle costs for any membrane-based water or wastewater treatment plant. The math is very simple: short membrane life drives costs up, long membrane life drives costs down. Shorter than expected membrane life not only increase life cycle costs, but it also generates an underserving negative perception of membranes as a whole. UF/MF membranes are critical for ensuring access to safe water due to the extremely high effluent quality they provide. When any particular membrane system does not live up to its expected performance, a negative perception that membranes are either too costly, too unreliable, or too difficult to operate & manage is created. This is particularly true in certain applications, such as membrane bioreactors, where shorter than expected membrane life is not uncommon, unfortunately. Membrane cleaning is a normal part of membrane plant operations regardless of application type. Unfortunately, chemical cleaning often dictates membrane life either by not fully recovering or by changing the properties of the membrane itself. In order to ensure membrane life is not compromised, it is necessary for all membrane systems to operate, without disruption or failure, to ever changing environments. This means being able to fully recover membrane permeability over its entire life, even when influent quality conditions change or deteriorate. Unfortunately, most membranes experience a gradual decline in permeability over time that accelerates as the membrane ages. The inability to completely recover a membrane sets in place the failure mechanism that can result in premature membrane replacement. Silicon carbide is a relatively new membrane material that helps solve many of the challenges associated with chemical cleaning. With a completely different set of material properties, compared to conventional polymeric membranes, SiC membranes do not experience the same degradation in permeability over time. SiC properties such as pore size, hydrophilicity or material strength are unaffected by prolonged chemical exposure.

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