Targeting Zeta Potential Value Versus Clarified Turbidity as Preatment to MF/UF

A major drawback of utilizing clarification/sedimentation ahead of low-pressure membranes is the issue of organic polymer addition (clarifier aid). Most membrane suppliers and design engineers restrict the use of this product to prevent potential accumulation within the membrane fiber and subsequent loss of beneficial use. Cationic polymers are specifically eliminated from consideration, although based on risk both non and anionic polymers are discounted as well. Organic polymer addition in conventional treatment enhances agglomeration of micro particles into particle masses which enhance settling and turbidity removal. This allows for smaller clarifier design, lower coagulant doses and greater turbidity removal.