Advanced, Robust, and Simple Pretreatment to Reverse Osmosis

The objective of this proposal is to demonstrate the feasibility of an innovative design that combines cross-flow filtration (CFF) and Dean Flow surface cleaning to achieve an effective self-cleaning filtration for Armys RO pretreatment. CFF is especially effective for feed flow with a high amount of colloidal solids that are commonly found in surface water. Unlike dead-end filtration, the surface dynamics of CFF does not make the gelatinous colloidal solids extrude through pores which often compromise the performance of filtration. The Dean Flow has a form of double vortices. The shear force of the vortices will prevent contaminants from adsorbing to the membrane wall. At the same time, the flow trajectory tends to push solids and contaminants toward the eye of the vortices, keeping them away from the membrane surface to minimize the fouling. The design also takes advantage of modern tubular membrane filter to engineer the flow path required for Dean Flow generation and to attain the required processed flow quality. The combination of the CFF and Dean Flow minimize the concentration polarization problem commonly found in membrane filtration.